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      AMERICAN SOCIETY OF CIVIL ENGINEERS
                Instituted 1852

                  TRANSACTIONS

                 Paper No. 1157

      THE NEW YORK TUNNEL EXTENSION OF THE
             PENNSYLVANIA RAILROAD.
       THE SITE OF THE TERMINAL STATION.[1]

     By GEORGE C. CLARKE, M. Am. Soc. C. E.


The purpose of this paper is to describe the preliminary work for and
the preparation of that portion of the site for the Terminal Station
in Manhattan, of the New York Tunnel Extension of the Pennsylvania
Railroad, which was constructed under the direction of the Chief
Engineer of the East River Division, including the disposal of material
excavated from all parts of the Terminal construction and the tunnels on
the East River Division.

As outlined in the paper by Brigadier-General Charles W. Raymond, M. Am.
Soc. C. E., Chairman of the Board of Engineers, the track yard of the
station, Plate LIII, extends from the east line of Tenth Avenue eastward
to points in 32d and 33d Streets, respectively, 292 and 502 ft. east of
the west line of Seventh Avenue. The width of the available area at
track level at Tenth Avenue is 213 ft., continuing at this width to
within 182 ft. of the west line of Ninth Avenue, where, by an offset
toward the south, it is increased to 355 ft. This width is held to a
point 5 ft. east of the east line of Ninth Avenue, where, by an offset
toward the north, it is increased to 509 ft., which width continues to
the west line of Seventh Avenue, where it divides into two fan-shaped
areas. The north area has a width of about 170 ft. and the south one,
160 ft., at the house line, each area tapering gradually to the width
of the standard three-track tunnel at the east ends, noted above in 33d
and 32d Streets. Additional track room for four tail-tracks is gained by
the construction of two double-track tunnels under Ninth Avenue at 33d
Street, their center lines being parallel to the street and 45.5 and
84.5 ft. distant, respectively, from the north house line. An additional
width of 24.5 ft. is occupied on the north from 277.5 ft. to 543.5 ft.
west of the west line of Seventh Avenue, where the buildings on the
north side of 33d Street have been torn down and the enclosing wall set
back in anticipation of a future outlet to 34th Street; and on the
south, from 459 ft. to 597 ft. west of the west line of Seventh Avenue a
rectangular offset of 124 ft. encloses the area occupied by the Service
Building. The total area above outlined is the space occupied at track
level, and amounts to 28 acres, of which the portion west of the east
house line of Ninth Avenue and south of a line 107.3 ft. south of the
south line of 33d Street is a part of the North River Division, and was
constructed under the direction of the engineers of that Division; the
fan-shaped areas east of the west house line of Seventh Avenue were
constructed under the direction of the Chief Engineer of Electric
Traction and Terminal Station Construction.

  [Illustration:
  Plate LIII.
  Pennsylvania Station, New York City: Plan Showing Area at Track Level]

In June, 1903, when the writer's connection with the work began, the
preliminary surveys had been completed and the location and extent of
the Terminal track area had been fixed, in so far as the city blocks to
be occupied were concerned. This contemplated area, however, did not
include the portion between Ninth and Tenth Avenues, that being added
subsequently. The elevation of the track level had also been fixed by
the requirement in the agreement with the City that no part of the
permanent structure should approach within 19 ft. of the surface under
any avenue or under any street except within the Terminal area. The
nearest approach of the tracks to the surface is at a point 320 ft. east
of Eighth Avenue, where the top of the rail is 40 ft. below the 31st
Street curb line.


WASH-BORINGS.

The general plan of enclosing the area in retaining walls having been
adopted, wash-borings were taken, for the purpose of determining the
best location for the walls, the depth of rock, and the nature of the
material overlying it. These borings were made along both curb lines of
Seventh Avenue, the east curb line of Ninth Avenue, the north curb line
of 33d Street, and the south curb line of 31st Street. The borings, as a
rule, were taken at intervals of approximately 100 ft., some deviation
in these intervals being made in order to prevent injury to water, gas,
and sewer connections, and, if the elevation of the surface of the rock,
as determined by one of these borings, corresponded fairly well with
the borings on either side of it, no intermediate borings were taken.
When a discrepancy appeared, a boring was taken midway between the
two non-corresponding ones, and if the information obtained from the
intermediate boring failed to account for the discrepancy, others were
taken at the quarter points of the original 100-ft. interval.

The dotted lines on Fig. 1 show the profiles of the surface of the rock
underlying 31st and 33d Streets, on the line of the borings, constructed
from the elevations obtained by them; the solid lines show the profiles
of the actual surface of the rock as found when uncovered. It will be
noted that, except in three cases, Borings 313, 328, and 333, the two
profiles correspond very closely at the points where the borings were
made, but they differ widely between those points, a variation of 5 ft.
being common; there is a variation of 14 ft. between Borings 324 and
327, and between Nos. 337 and 340; and of 12 ft. between Nos. 333 and
335, and between Nos. 312 and 313, while an extreme variation of 17 ft.
is shown between Nos. 303 and 305. At each of the points where the
variation is great the interval between borings is the full 100 ft., and
it is quite apparent that, if a definite idea is to be obtained of the
elevation of the surface of the rock in Manhattan, borings must be taken
at shorter intervals.

The necessary width of trench for the construction of the retaining
walls was determined by the elevation of the rock, as shown by the
borings, and only in the case of the dip between Borings 303 and 305
did the variation lead to any difficulty. The trench at that point had
to be widened after rock was reached. This depression corresponded very
closely in location to that of one arm of the creek shown on General
Viele's map of 1865,[2] the bed of that stream, or one in approximately
the same location, being clearly marked across the excavation by
smoothly-worn rock and well-rounded boulders. The original stream,
however, seemed to have turned in a westerly direction under 31st Street
to Eighth Avenue instead of crossing, as shown on General Viele's map.

  [Illustration:
  Fig. 1.
  PROFILE OF ROCK SURFACES IN THIRTY-FIRST AND THIRTY-THIRD STREETS,
  BETWEEN SEVENTH AND NINTH AVENUES]


SEWERS.

The arrangement of the sewers in the streets in the vicinity of the
Terminal Site, previous to the beginning of the construction, and the
drainage area tributary to those sewers, is shown by Fig. 2. The main
sewer for this district was in Eighth Avenue, and was a 6-ft. circular
brick conduit within the Terminal area. The sewers leading to it from
the west, in 31st, 32d, and 33d Streets, were elliptical, 3 by 2 ft.,
and egg-shaped, 4 ft. by 2 ft. 8 in., although in no case did they drain
more than one block, and they were on a heavy grade. Draining into
Eighth Avenue from the east, the one on 31st Street was 4 ft. by 2 ft.
8 in., egg-shaped, and drained a length of two blocks, and those on 32d
and 33d Streets were circular, 4 ft. in diameter, and drained the
territory for three blocks, or as far east as Fifth Avenue. There were
no sewers in Seventh Avenue within the Terminal area, except small
vitrified pipes, each less than 200 ft. in length.

It was desirable that the size and number of the sewers in the streets
and avenues surrounding the Terminal should be reduced to a minimum, on
account of the difficulty of caring for them during construction and
also to reduce the probability of sewage leaking into the underground
portion of the work after its completion. With this in view, the plan
was adopted of building an intercepting sewer down Seventh Avenue from
north of 33d Street to the 30th Street sewer, which, being a 4-ft.
circular conduit, was sufficiently large to carry all the sewage coming
from east of Seventh Avenue and south of 34th Street. It was decided to
build this sewer of cast iron where it crossed the proposed construction
work, and also to replace with cast iron the brick sewers on 31st, 32d,
and 33d Streets from Seventh Avenue to a point east of the west end of
the standard tunnel section, and also the sewer on Eighth Avenue from
the north side of 33d Street to the south side of 31st Street. This
arrangement permitted: first, the removal of the sewer in 32d Street
between Seventh and Eighth Avenues, which was necessary, as that street
was to be excavated; second, the reduction of the sewer in Eighth Avenue
from a 6-ft. to a 5-ft. circular conduit; and, third, assuming that the
sewage and drainage from the Terminal would be pumped directly to the
sewers in the avenues, the reduction of the sewers in 31st and 33d
Streets, from Seventh to Ninth Avenue, to 15-in. vitrified pipes, except
west of the Service Building in 31st Street, to accommodate which
section, a larger sewer was required. The sewer in 32d Street, from
Ninth to Eighth Avenue, of course, could be dispensed with in any
arrangement, as all the area tributary to it was to be excavated.

  [Illustration:
  Fig. 2.
  PLAN SHOWING LAYOUT OF SEWER IN CATCHMENT AREA ABOUT TERMINAL STATION]


GAS AND WATER MAINS.

A rearrangement of the gas pipes in the three streets crossing the
Terminal site was necessary. These pipes were of two classes: trunk
mains and service mains. Fortunately, there were but two trunk mains
in the three streets, one a 20-in. in 31st Street from east of Seventh
Avenue to Ninth Avenue, the other a 16-in. in 32d Street from east of
Seventh Avenue to Eighth Avenue. The 20-in. main was relaid from Seventh
Avenue and 31st Street down Seventh Avenue to 30th Street and through
that street to Ninth Avenue. The 16-in. main was relaid from Seventh
Avenue and 32d Street north to 34th Street and through that street to
Eighth Avenue. The service mains in 32d Street were no longer required,
and were taken up and not replaced. The houses on 31st and 33d Streets
were provided with service by two 6-in. wrought-iron mains back of the
retaining walls in each street, that location being chosen to avoid
damage by gas drip to the water-proofing of the street bridges. As the
permanent structures under the avenues were not to approach the surface
nearer than 19 ft., only slight rearrangements, sufficient to permit the
new sewers and water lines to be laid, were necessary.

There were no large water mains to be cared for, in fact, those in the
streets were too small for ample fire protection, being only 6 in. in
diameter. The main in 32d Street was taken up and not replaced, and
those on 31st and 33d Streets were replaced by 12-in. pipes laid back
of the retaining walls. No changes were necessary in the mains in the
avenues, but, before approving the rearrangement for the streets, the
Department of Water Supply, Gas and Electricity added a 48-in. main in
Eighth Avenue to be laid as a part of this construction, the pipe being
supplied by the City.


LOCATION AND DESIGN OF RETAINING WALLS.

The plans, from the earliest stages, contemplated founding the
retaining wall on the surface of the rock, where of suitable quality,
and afterward excavating the rock in front of the toe of the wall
to sub-grade. This plan was definitely adopted soon after the borings
were completed, on account of the great danger of blasting out large
quantities of rock in timbered trenches close to buildings founded on
soft material, and also to avoid the additional cost and delay that
would have been caused by carrying the walls to sub-grade. The retaining
walls in Seventh Avenue, south of the viaduct, and in Ninth Avenue,
north of the viaduct, were not governed by the same conditions as in the
streets. The dip and quality of the rock at both points required that
the walls be carried to sub-grade, and they are, in fact, face walls;
the Ninth Avenue wall, in particular, having little thrust to sustain,
is very light.

The results aimed at in the design and location of the retaining walls
in 31st and 33d Streets were:

  _First._--A perfectly stable wall under all conditions that might
    reasonably be expected;

  _Second._--As much room as possible at the elevation of the top of
    rail;

  _Third._--The least necessary interference with adjoining property
    during construction; and,

  _Fourth._--The most economical wall that would fulfill the other
    conditions.

As stated in the paper by Alfred Noble, Past-President, Am. Soc. C. E.,
the third stipulation required the relinquishing of a portion of the
space under these streets granted by the City, but it was finally
decided not to approach the south house line of 31st Street with the
back of the walls nearer than 9 ft., while on 33d Street the extreme
position of the back was fixed at the north line, as there were no
buildings, except those belonging to the Railroad Company, on the house
line at the low points in the rock.

The assumptions made in designing the wall were as follows:

  _First._--Weight of concrete, 140 lb. per cu. ft.

  _Second._--Weight of material from the surface of the ground to a
    depth of 12 ft. (which was shown by tests made in bore-holes to be
    the elevation of the ground-water surface), 100 lb. per cu. ft.;
    and angle of repose, 30 degrees. The distance of 12 ft. below
    the surface was the depth of the inverts of the sewers, which
    undoubtedly drained the ground above them, thus accounting for the
    standing of the ground-water in planes practically parallel with
    the surface.

  _Third._--Weight of buildings back of wall neglected, as that of the
    present type will about equal the cellars filled with material at
    100 lb. per cu. ft., and if large buildings are erected in the
    future they will undoubtedly be carried to rock.

  _Fourth._--Reaction from superstructure, live and dead load, 20,000
    lb. per lin. ft. of wall.

  _Fifth._--Weight of materials below the 12-ft. line, 124 lb. per
    cu. ft., ascertained as follows: The material was considered as
    weighing 165 lb. per cu. ft. in the solid, and having 40% of voids
    filled with water at 62.5 lb. per cu. ft., the resulting weight
    being (165 × 60/100) + (62.5 × 40/100) = 124 lb. per cu. ft.

Various angles of repose were used for this material in the
investigation, and it was finally decided that 30° was the greatest
angle that could be expected, whereas the worst condition that could be
anticipated was that the sand and water would act separately and give a
pressure as follows:

Hydraulic pressure from liquid weighing 62.5 lb. per cu. ft. plus
pressure from sand with angle of repose at 30° and weight as follows:

Weight of 1 cu. ft. in air = 165 × 60/100 = 99 lb.

Weight of water displaced by 1 cu. ft. = 60/100 × 62.5 lb. = 37.5 lb.

Weight in water, therefore = 61.5 lb. per cu. ft.

These combined weights, of course, are equal to the weight of the
combined material in the previous assumption.

  _Sixth._--The usual requirement that the resultant of both horizontal
    and vertical forces should, at all points, fall within the middle
    third of the wall, or, in other words, that there should be no
    tension in the concrete.

  [Illustration:
  Plate LIV.
  Diagram Showing Widths of Base of Retaining Wall Required
  for Different Batters and Pressures, Pennsylvania Station]

With these assumptions, investigation was made of walls with various
batters and differently designed backs. This investigation developed the
fact that the reaction from the superstructure was so great that, for
economy, both in first cost and space occupied, the batter must be
sufficient to cause that reaction to fall within or very close to the
middle third. Nothing could have been gained by having that reaction
fall back of the front of the middle third, as the wall was required
to be stable against the full pressure before the superstructure was
erected, and in case it should ever be removed; or, to state the matter
more clearly, the reaction from the superstructure was so great in
comparison to the weight of the wall, that, if it fell in front of the
resultant of all the other forces, the width of base required would be
greatly increased to make the wall stable after the superstructure was
erected; whereas, if the reaction from the superstructure fell back of
the resultant of all the other forces, the width of base could not be
correspondingly decreased without danger of the wall being overturned
before the superstructure was erected. The least batter that would
answer those conditions was found to be 2 in. per ft.

For convenience in designing, and economy in constructing, the
steelwork, the faces of the bridge seat and of the backwall were laid
parallel to the center line of the Terminal, and in elevation on line
parallel to the top of the curb and as near to it as the economical
depth of steel would permit, without bringing the finished construction
above the plane fixed in the ordinance. As there is a variation of 13
ft. in the elevation of the top of the curb of 31st Street above the top
of rail and a variation of 18 ft. in 33d Street, a uniform batter, with
the top parallel to the center line, would produce a toe varying in
distance from it and from the other constructions. It was decided,
therefore, for the sake of appearance, to make the face of the wall
(or wall produced) at the top of rail parallel to the center line,
and to vary the batter accordingly, using the 2-in. batter previously
mentioned as the minimum. This gave a maximum batter of 3 in. per ft. The
variation is so gradual that it is unnoticeable, and is not sufficient
to introduce any complications in construction.

The wall was designed with a stepped back, primarily to allow the
water-proofing and brick protection to be held in position more readily.
The first step was put at 13 ft. below the surface of the ground. This
gave a vertical back above that point for a 3-in. battered face, and a
slightly battered back for sections having a less batter in front. Below
that point a step was added for each 5 ft. of depth to the elevation
of the top of rail, or to the foundation of the wall if above that
elevation. As the horizontal distance of the heel of the wall, at its
greatest width, from its face at the top of rail would determine the
effective room to be occupied by the wall, it was determined to make the
back vertical below the top of rail and gain the necessary increase in
width below that point by making a heavy batter on the face.

The type of wall having been thus determined, calculations were made
of the width of base required for each ¼-in. batter from 2 to 3 in.,
inclusive, first for a depth of 13 ft. below the top of the curb and
then for each 5 ft. below that elevation, to a depth corresponding to
the distance between the top of the curb and the top of the rail at the
point of greatest variation. These widths of wall were determined for
the two pressures previously decided on, and curves were then plotted
showing the thickness of wall required for each batter calculated and
for each pressure. They are shown on Plate LIV. The curves in broken
lines represent the widths required for saturated material, and the
curves in dotted lines for hydraulic pressure. Mean curves were then
drawn between each broken and its corresponding dotted curve. These are
shown in solid lines, and represent the widths of wall which were used
in the construction. Typical sections of the wall and pipes back of it
are shown on Fig. 3.

The extreme positions of the back of the wall on the two streets having
been determined, as previously stated, the width of base required at
those points fixed the toe of the wall at the top of rail as 254.5 ft.
south of the center line of the Terminal in 31st Street, and 258.5 ft.
north of the center line in 33d Street.

  [Illustration:
  Fig. 3.
  TYPICAL SECTIONS OF RETAINING WALL IN THIRTY-FIRST STREET]


CONTRACTS.

The construction was done under the following contracts:

_1._--The principal contract, dated June 21st, 1904, was with the New
York Contracting and Trucking Company, later assigned by that company
to the New York Contracting Company-Pennsylvania Terminal, for the
performance of the following works:

  (_a_).--The excavation for and construction of a retaining wall in
    Seventh Avenue, 31st Street, Ninth Avenue, and 33d Street.

  (_b_).--Excavation over the area enclosed by the retaining wall.

  (_c_).--The building of sewers and the laying of water and gas pipes.

  (_d_).--The building of a timber trestle to support the surface of
    Eighth Avenue between the south side of 31st Street and the north
    side of 33d Street, and also the surface of 31st and 33d Streets
    between Seventh and Ninth Avenues. This refers to the trestles left
    in place on the completion of the work.

  (_e_).--The building of a trestle and bridging from a point near the
    west side of Tenth Avenue on the south side of 32d Street, westward
    to the outer end of Pier No. 62, at the foot of 32d Street.

_2._--The second contract, dated February 10th, 1905, was with the New
York Contracting Company-Pennsylvania Terminal, for the excavation for
and construction of retaining walls for the Manhattan Terminal Power
Station, and the excavation of the area thus enclosed.

_3._--The third contract, dated October 2d, 1907, was with the New York
Contracting Company-Pennsylvania Terminal, for the construction of two
twin tunnels under Ninth Avenue, and other work incidental thereto.

Sewers and gas mains laid outside the area covered by the foregoing
contracts were constructed under the following agreements:

An agreement, dated August 9th, 1904, between the New York Contracting
Company-Pennsylvania Terminal, and the New Amsterdam Gas Company, for a
20-in. gas main from Seventh Avenue and 31st Street to 30th Street, and
thence to Ninth Avenue, the New Amsterdam Gas Company being remunerated
for the cost by the Tunnel Company.

A contract, dated August 24th, 1904, with the New York Contracting
Company-Pennsylvania Terminal, for the construction of sewers in Seventh
Avenue and in 32d and 33d Streets east of Seventh Avenue.

A contract, dated November 24th, 1908, with the New York Contracting
Company-Pennsylvania Terminal, for the construction of a 16-in. gas main
from Seventh Avenue and 32d Street to 34th Street, and thence to Eighth
Avenue.

All these contracts required that the excavated material be delivered on
board scows to be furnished by the company at the pier at the foot of
32d Street, North River. These scows were furnished and the material
was disposed of from that point by Henry Steers, Incorporated, under a
contract, dated August 9th, 1904, which called for the transportation to
and placing of all material so delivered in the Pennsylvania Railroad
Company's freight terminal at Greenville, N.Y.

The disposal of the excavated material was one of the principal features
of the work, and, under the above contract, material from those portions
of the Terminal site east of Seventh Avenue and west of Ninth Avenue,
and from all substructures work, was disposed of, as well as from the
constructions herein described. The problem differed from that presented
by the usual foundation excavations in New York City in magnitude only,
and the methods were not unusual, but were adaptations of the usual ones
to exceptionally large work.


PIERS AND TRESTLE FOR DISPOSAL.

The most rapid and economical handling of all excavated material to
scows was made possible by the Tunnel Company procuring from the New
York Central and Hudson River Railroad Company the pier at the foot of
32d Street, North River, known in the earlier stages of the work as Pier
No. 62, but subsequently changed to Pier No. 72, and thus referred to in
this paper. This pier was occupied by a freight-shed used by the New
York Central Railroad Company, under a long-term lease from the City,
and that Company had to make numerous changes in their tracks and
adjoining piers before No. 72 could be turned over; the contract for
the excavation, therefore, required the contractor to procure any piers
needed previous to and in addition to it. Under this clause of the
agreement, the contractor procured one-half of the pier at 35th Street,
North River, which was used for the disposal of all material excavated
previous to May 22d, 1905, on which date Pier No. 72 was first put in
service.

As the type of plant the contractor would elect to use could not be
determined, previous to the letting of the contract, a general plan for
Pier No. 72 and the trestle approach, suitable for either trains or
wagons, was attached to the contract, and the details were worked out
afterward. The method adopted was by train, and a two-track approach to
the pier was provided. Beginning on the east side of Ninth Avenue, at
the south line of 32d Street, at an elevation of 20 ft. below the
surface, crossing under Ninth Avenue and to the center line of 32d
Street, it rose on a 1.5% grade in open cut to the surface of 32d Street
at a point 500 ft. west of Tenth Avenue, from which point it rose above
the surface of the street on a timber trestle to Tenth Avenue, which was
crossed overhead. West of Tenth Avenue the line changed by a reverse
curve to the south sidewalk of 32d Street, and continued on a timber
trestle, practically level, to the New York Central Yard tracks near
Eleventh Avenue. These tracks and Eleventh Avenue were crossed overhead
on a through-truss, steel bridge, and a column-and-girder construction
on which the two tracks separated to a distance of 29 ft, between center
lines, so as to bring them directly over the posts of special timber
bents which spanned the two house tracks of the New York Central
south-bound freight shed, which the trestle here paralleled. This
position was held to a point 25 ft. west of the east house line of
Twelfth Avenue, where, by a system of cross-overs and turn-outs, access
was had from either track to six tracks on the pier. Four of these were
on upper decks, two on the north and two on the south edge of the pier,
at an elevation of 41 ft. above mean high tide, to carry earth and small
rock to chutes from which it was dumped into barges. The other two
tracks proceeded by a 5.3% grade down the center of the pier to the
lower deck where, at a distance of 540 ft. from the bulkhead, and beyond
the upper deck construction, they diverged into six, two on the north
and two on the south edge of the pier for standing tracks to serve
derricks, and two down the center for shifting purposes. A siding to the
north of the two running tracks just west of the bottom of the incline
served a bank of eight electric telphers. The arrangement of the pier is
shown by Fig. 4.

The trestle east of the steel structure at Eleventh Avenue had simple
four-post bents, as shown by Bent "_A_," on Fig. 5, all posts being
vertical, to save room at the street level; the outside posts and the
caps and sills were of 12 by 12-in. timber; the intermediate posts were
of 8 by 12-in. timber; and single or double decks of 3 by 8-in. bracing
were used, depending on the height of the bents. These bents were framed
on the ground in position and raised by hand. West of Tenth Avenue, the
sills of the bents rested on four 12 by 12-in. longitudinal timbers,
each spanning two bays and breaking joints, for convenience in
supporting the trestle while the tunnels were constructed in open cut
beneath. These bents were placed 12 ft. on centers, with one 8 by 16-in.
stringer under each rail, and one 6 by 16-in. jack-stringer supporting
the overhang of the floor on either side.

The bents along the New York Central freight shed had but two posts of
12 by 14-in. yellow pine varying from 26 ft, to 31 ft. 9 in. from center
to center; they had double caps of 12 by 14-in. yellow pine on edge, no
bottom sills or bracing, and the vibration and wind pressure were taken
care of by the top bracing and anchorage, as shown by Bent "_G_," on
Fig. 6.

  [Illustration:
  Fig. 4.
  PLANT FOR DISPOSAL OF EXCAVATED MATERIALS PIER NO. 72 N.R.]

The method of erection was as follows: An excavation was made on the
line of each post, 4 ft. deep and from 4 to 5 ft. square, depending on
whether it was for a single or reinforced post; 6 in. of concrete was
placed in the bottom, and on this were laid, at right angles to the
center of the trench, three 8 by 12-in. timbers varying in length with
the excavation from 3 to 4 ft. To these timbers was drifted one 12 by
12-in. timber of the same length as those in the bottom row, but at
right angles to them. Elevations were then taken on top of the 12 by
12-in. timber, and the bent was framed complete and of correct height.
The framing was done south of the line of the trestle and west of the
freight-house. The framed bents were picked up by a small two-boom
traveler carrying two double-drum, electric, hoisting engines, and run
forward into position. A hole had previously been made in the metal
gutter and canopy of the freight-house, by an experienced roofer, and
in the freight platform underneath, and, as soon as the bent had been
dropped into position, it was firmly drifted to the foot-blocks,
previously described, and the excavation made for them was filled with
concrete well rammed about the blocks and rounded off 6 in. above the
surface of the ground. Secure flashings, in two sections, were then made
about the posts to cover the holes made in the gutter and roof, the
bottom sections being firmly soldered to the roof or gutter, and the top
sections, which lapped over the bottom and cleared them 2 in. in all
directions, were firmly nailed to the posts and the joints leaded. This
arrangement allowed the bents to move slightly, and at the same time
made the roof and gutter water-tight. These bents were placed 16 ft. on
centers to correspond with the spacing of the doors of the freight shed.

Under the cross-overs near Eleventh Avenue, where the tracks had to
be supported in different positions on the caps, and could no longer
be kept over the posts, the caps were trussed and the posts were
reinforced, as shown on Bents "_J_," "_H_," and "_K_," Fig. 5.

  [Illustration:
  Fig. 5.
  DETAIL OF BENTS FOR MATERIAL TRESTLE]

The trusses for the through bridge over the tracks were erected on
Sunday, April 16th. The two trusses, one 122 ft. and the other 165 ft. 8
in. from center to center of end posts, had been assembled and riveted,
lying flat on cribwork a few feet above the ground, south of the
permanent position and between the New York Central tracks and Eleventh
Avenue. On the date stated, the contractor, having been given permission
to block the Central's tracks from 5 a.m. to 9 p.m., erected a large
steel gin pole just south of the correct position of the center of the
north truss, which was then dragged, from the place where it had been
assembled, across the railroad tracks until the center of the bottom
chord was vertically under its true position, the truss still lying flat
and about at right angles to the center line of the bridge. Chains were
made fast to the top chord at the middle panel of the truss, which was
then turned up to a vertical plane, raised to its permanent position,
and guyed. The gin pole was then shifted and the operation repeated with
the longer truss, after which, half of the floor beams and a part of the
top laterals were bolted in position and the guys were removed, the
bridge being thus erected without the use of falsework of any kind.
During the lifting there was no sag in either truss that could be
noticed by the eye. Fig. 1, Plate LV, shows the bridge erected, with
the exception of the tight timber fence.

Pier No. 72 is directly over the North River Tunnels. When it was turned
over by the New York Central Railroad Company, the contractor for the
construction of those tunnels tore down the shed and removed the deck
and such piles as were in the path of the tubes. This left standing the
four northernmost, the four southernmost and two centers rows of piles
for the entire length of the pier. An additional row of piles was then
driven on either side of the two center rows, and battered so that at
the elevation of the tunnels they would be close to the center rows
and leave as much clear space as possible. The pier, therefore, was
constructed of three independent lines of four-post bents, which,
however, rested on sills which were continuous throughout the width of
the pier, as shown by Figs. 2 and 3, Plate LV.

  [Illustration:
  Fig. 6.
  DETAIL OF BENTS FOR MATERIAL TRESTLE.]

The bents for the upper floors of the pier were double-decked, with
12 by 12-in. posts, sills, intermediate and top caps, and 3 by 8-in.
longitudinal and cross-bracing. The bents for the incline were similar,
except that those below 16 ft. in height were of single-deck
construction. The spacing of the bents varied from 9 ft. 6 in. to 12
ft., except the three outer bays, which had a span of 23 ft., all to
agree with the position of the pile bents. The double-deck construction
extended for the full length of the original pier. A single-deck
extension, of full width and 180 ft. in length, was subsequently built
for the accommodation of four derricks for handling building material
and large rock. The piles for this extension were driven in three sets
of four rows each, similar to those in the old portion of the pier,
except that the bents were driven with a uniform spacing of 15 ft.
between centers. The three sets of bents were topped separately with
12 by 12-in. caps and 12 by 12-in. dock stringers; they were braced with
both cross and longitudinal low-water bracing, and were tied together by
a continuous 12 by 12-in. timber over the dock stringers and 12 by
12-in. packing pieces from stringer to stringer, each of these ties
being supported in the center of the span over the tunnels by two 2-in.
hog rods, Section "_A-A_," Fig. 4.

The south side of the upper deck of the pier carried three sets of nine
hoppers, each set covering 90 ft., a little less than the full length
between bulkheads of the largest deck scows, with 70 ft. clear between
sets, to allow for the length of a scow outside of the bulkhead and to
permit the free movement of boats. Each hopper occupied the full space
between two bents, and, as the caps were topped by strips of timber of
triangular section, with a width of 12 in. on the base and a height of
6 in., protected by a 6 by 6-in. steel angle, each set of hoppers
presented 90 lin. ft. of continuous dumping room. The bottoms of the
hoppers, set at an angle of 45°, were formed by 12 by 12-in. timbers
laid longitudinally, running continuously throughout each set, and
covered by 3-in. planking. The partitions were formed with 4-in. planks
securely spiked to uprights from the floor of the hoppers to the caps;
these partitions narrowed toward the front and bottom so as to fit
inside the chutes. Each hopper was lined on the bottom and sides with
½-in. steel plates, and the bottoms were subsequently armored with 2 by
1-in. square bars laid 3 in. on centers and bolted through the 12 by
12-in. flooring of the hoppers. The chutes, extending from the bottom of
the hoppers, were 20 ft. long and 7 ft. wide, in the clear; they were
formed entirely of steel plates, channels, and angles, and were
supported from the upper deck of the pier by chains; their lower ends
were 17 ft. above mean high tide and 14 ft. 6 in. from the string piece
of the pier. The hoppers and chutes are shown by Fig. 1, Plate LVI.

  [Illustration:
  Plate LV.
  Material Trestle Over N.Y.C. & H.R.R.R. Co.'s Tracks;
    and Construction of Pier No. 72, North River
  Fig. 1.--Material Trestle Over N.Y.C. & H.R.R.R. Co.'s Tracks.
  Fig. 2.--Material Trestle Under Construction on Pier No. 72,
    North River, Showing Clear Water Over Tunnel Location.
  Fig. 3.--Pier No. 72, North River, Showing Incline as Reconstructed
    For Locomotives.]

A length of 150 ft. of the north side of the pier was for the use of the
contractor for the North River tunnels; it was equipped with a set of
nine chutes similar to those for the south side; they were used but
little, and were finally removed to make room for a cableway for
unloading sand and crushed stone.

At the foot of the incline there was a bank of eight telphers running
on rails securely bolted to the tops of 20-in. I-beams, which were hung
from stringers resting on the upper caps. The beams were erected in
pairs, each pair being securely braced together and to the trestle posts
to prevent swaying. Each telpher occupied the space between two bents,
about 10 ft., so that the entire bank commanded a length of 80 ft.,
which was approximately the length of a rock scow between bulkheads. All
supports for the telphers were provided as a part of the trestle, but
the machines themselves were a part of the contractor's plant.

Four derricks were erected on the extension, two on the north and two on
the south edge of the pier, supported on bents at a sufficient elevation
above the floor to clear a locomotive.

After most of the earth had been excavated, the out-bound set of hoppers
on the south side of the pier was removed, and two derricks were erected
in their place and used for unloading sand, crushed stone, and other
building material.


PLANT.

As the use of the 35th Street pier for the disposal of material required
that the mode of transportation should be by dump-wagons drawn by
horses, the plant in use by the contractor during that period
necessarily differed in many respects from what it was later, when Pier
No. 72 was available. Therefore, the nature of the plant during each
period will be stated. The plant for each period will be divided into
five classes:

  1.--Central Plant:
    (_a_) Power-Generating Plant.
    (_b_) Repair Shops.
  2.--Retaining-Wall Plant.
  3.--Pit-Excavating Plant.
  4.--Transportation Plant.
  5.--Dock Plant.

Horse-and-Truck Period: July 11th, 1904, to May 22d, 1905.

_1._--_Central Plant._

(_a_).--_Power-Generating Plant._--The contractor's first central
generating plant was established in a 35 by 85-ft. steel-framed building
covered with corrugated iron, the long side being parallel to Ninth
Avenue and 15 ft. from the east house line, and the north end 43 ft.
south of the south house line of 32d Street. The foundations for the
building and machinery were of concrete, resting on bed-rock, the floor
being 20 ft. below the level of the Ninth Avenue curb. The south end of
the building was the boiler-room and the north end the compressor-room,
the two being separated by a partition. Coal was delivered into a large
bin, between the boiler-house and Ninth Avenue, its top being level with
the street surface, and its base level with the boiler-room floor.

At the end of the horse-and-truck period the plant consisted of:

  Two Rand, straight-line compressors, 24 by 30 in., having a capacity
    of 1,400 cu. ft. of free air per min. when operating at 86 rev. per
    min. and compressing to 80 lb. above atmospheric pressure.

  One 10 by 6 by 10-in., Worthington, steam, plunger pump.

  Three horizontal boilers of the locomotive type, each of 125 h.p.

(_b_).--_Repair Shops._--The repair shops, which included blacksmith,
machine and carpenter shops, were located on the first floor of a 40 by
70-ft. two-story frame structure, which was in the pit on the north side
of 31st Street, 48 ft. east of Ninth Avenue. The second floor was on the
street level, and was used as a storehouse for hand-tools and small
plant.

The blacksmith shop contained: Four forges with hand blowers, four
anvils, and hand-tools.

The machine shop contained: One drill press, one shaper (14-in. stroke),
one 18-in. swing lathe, and one 6-in. bed lathe.

The carpenter shop contained: One circular saw, one wood lathe, and
hand-tools.

The plant in both machine and carpenter shops was operated by one
7½-h.p. General Electric motor, the current for which was obtained from
the Edison Electric Heat, Light, and Power Company.

  [Illustration:
  Plate LVI.
  Material Trestle Showing First Chutes in Operation;
    and Views of East and West Pits at Terminal Site
  Fig. 1.--Material Trestle, Showing First Chutes in Operation.
  Fig. 2.--East Pit, Steam Shovel Loading Excavated Material on Car.
  Fig. 3.--West Pit, Showing Condition on June 28th, 1905.]

_2._--_Retaining-Wall Plant._

  Three cableways, with 35-ft. towers of 12 by 12-in. yellow pine timber
    capable of spanning 350 ft., and operated by 7 by 10-in. double-drum
    Lambert hoisting engines mounted with 25-h.p. Lambert upright
    boilers.

  Five stiff-leg derricks, with masts from 35 to 50 ft. long and booms
    from 45 to 60 ft. long, operated by 7 by 10-in. Lambert double-drum
    and swinging gear engines, mounted with 25-h.p. upright Lambert
    boilers.

  Six Cameron pumps, varying in size from 7 by 6 by 13 in. to 10 by 8
    by 16 in. The first dimension referring to the diameter of the steam
    cylinder, the second to that of the water, and the third to the
    stroke.

  Five Rand sheeting drivers.

  Two Ransome ¾-cu. yd. concrete mixers, mounted on frame, with
    kerosene driving engine.

  Drills drawn from pit plant as required.

_3._--Pit-Excavating Plant.

  One guy derrick, 50-ft. mast and 45-ft. boom, operated by a Lambert
    two-drum and swing-gear hoisting engine, with Lambert 25-h.p.
    upright boiler.

  Three stiff-leg derricks, similar to those used on the retaining wall
    work.

  Three Bucyrus, 70-ton steam shovels with 3½-cu. yd. dippers.

  One traveling derrick, built with an A-frame of 12 by 12-in. timbers,
    15-ft. mast, and 25-ft. boom; the traveler carried an engine and
    boiler similar to those used on the stiff-leg derricks, and was
    used on the Seventh and Eighth Avenue sewers, as well as in the pit.

  Ten Rand-Ingersoll rock drills, Nos. 1, 3¼, and 4.

  One Reliance stone crusher (nominal capacity 17 tons of crushed stone
    per hour) belt-driven by 50-h.p. engine.

_4._--_Transportation Plant._

  During the whole of the first period the transportation plant
    consisted of two-horse trucks and snatch teams as needed. The number
    varied greatly from 25 at the beginning and end of the period to an
    average of 135 from August 1st to December 1st, 1904, about 10% of
    the total number of teams being used as snatch teams.

_5._--_Dock Plant._

  The only machinery used on the dock during the horse-and-truck period
    was one stiff-leg derrick similar in size and operation to those
    described under the head of retaining-wall plant.

The plant described above does not represent that which was used during
the whole of the horse-and-truck period, but what had accumulated at the
end of it. The power-generating plant might almost have been omitted
from this period, as the first compressor did not begin running until
February, 1905. Previous to that time, the power for drilling, pumping,
driving, sheeting, etc., was steam furnished by the boilers which
subsequently drove the compressors, these being brought on the ground
and fired as occasion required.


Train-Disposal Period, Beginning May 22d, 1905.

At the beginning of this period there had been excavated 242,800 cu. yd.
of earth and 22,800 cu. yd. of rock, of the total excavation of 803,500
cu. yd. of earth and 804,000 cu. yd. of rock included in the principal
contract, leaving to be excavated under that contract 560,000 cu. yd. of
earth and 781,200 cu. yd. of rock, and an additional contract had been
let to the New York Contracting Company for the terminal power station,
which increased the earth by 16,500 and the rock by 15,500 cu. yd.
During the year following, contracts for the east and west portions and
the sub-structures were let, which brought the total to be excavated,
after the beginning of the train-disposal period, up to 681,000 cu. yd.
of earth and 1,494,000 cu. yd. of rock.

The central plant, transportation plant, and dock plant were used
indiscriminately on all these contracts, and, as no separation can be
made which will hold good for any appreciable length of time, the plant
in those classes will be stated in total. The retaining-wall and pit
plant here given include that used on the principal contract and
terminal power station only. The power-generating plant given under
the horse-and-truck period was doubled at the beginning of the
train-disposal period, but it was still insufficient for the work then
under contract, and the additional contracts necessitated a greater
increase. The location had also to be changed to permit the excavation
of the rock under Ninth Avenue. The old stone church fronting on 34th
Street, between Seventh and Eighth Avenues, a building 68 ft. wide and
92 ft. long, made a roomy and very acceptable compressor-house. The
wooden floors and galleries were removed, and good concrete foundations
were put in, on which to set the plant; the walls, which were cracked in
several places, were trussed apart and prevented from moving outward by
cables passed about the pilasters between the windows.

The boilers were erected south of the church, an ash-pit being first
built, the full width of it, with the floor on a level with the
basement. The rear wall of the church formed the north wall of the
ash-pit, and the south wall and the ends were built of concrete. The
boilers were set with the fire-doors toward the rear wall of the
building, and 7 ft. distant from it, and above this fire-room and the
boilers there was erected a coal-bin of 500 tons capacity. The rear wall
of the compressor-house formed the north wall of the bin, the section
of which was an isosceles right-angled triangle. Coal was delivered by
dumping wagons into a large vault constructed under the sidewalk on 34th
Street, and was taken from there to the bin by a belt conveyor.

The plant for the second period was as follows:

_1._--_Central Plant._

(_a_).--_Power-Generating Plant._--The plant in the engine-room
consisted of:

  Three Rand straight-line compressors from the original power plant at
    Ninth Avenue and 32d Street.

  One Ingersoll straight-line compressor from the old power-house.

  One Rand duplex Corliss, 40 by 48-in. air-compressor, with both air
    and steam cylinders cross-compounded, and a capacity of 5,600 cu.
    ft. of free air per min. compressed to 80 lb. at 70 rev. per min.

  Three Rand duplex, 30 by 30-in., compressors, connected with 525-h.p.,
    6,600-volt, General Electric motors, with a capacity of 3,000 cu.
    ft. of free air per min. compressed to 80 lb. at 125 rev. per min.

  Two 10 by 6 by 10-in. Worthington steam plunger pumps.

  One 7½-h.p. General Electric motor for driving the Robbins belt coal
    conveyor.

  One forced-draft fan (built by the Buffalo Forge and Blower Company),
    driven by an 8 by 10-in. Buffalo engine.

In the boiler-room there were three 500-h.p. Sterling water-tube
boilers.

(_b_).--Repair Shops.--The repair shops remained in their old location
until sufficient room had been excavated to sub-grade in the lot east
of Eighth Avenue, and then they were moved to the old Ninth Avenue
power-house which had been erected at that point. The contents of the
blacksmith shop remained the same as for the first period. The equipment
of the machine shop was increased by one 18-ton trip-hammer operated by
air and one bolt-cutting machine, size 1 in. to 1½ in. The carpenter
shop remained the same except that the electric motor was replaced by a
25-h.p. single-cylinder air motor; there was added to the repair shop a
drill shop containing: Four forges with compressed air blowers, four
anvils, two Ajax 20-ft. drill sharpeners, and one oil blower forge.

_2._--_Retaining-Wall Plant._

The retaining-wall plant was identical with that described for the first
period, with the addition of two Ransome 1-cu. yd., concrete mixers,
with vertical engines mounted on the same frame, using compressed air.

_3._--_Pit-Excavating Plant._

The pit-excavating plant included that listed for the first period and,
in addition, the following:

  One Vulcan, 30-ton, steam shovel, with 1-cu. yd. dipper and a vertical
    boiler.

  One Ohio, 30-ton, steam shovel, with 1-cu. yd. dipper and a vertical
    boiler.

  Four guy derricks (50 to 80-ft. masts and 45 to 60-ft. booms),
    operated by Lambert 7 by 10-in. engines, with two drums and swinging
    gear, mounted with 25-h.p. vertical boilers, but driven by
    compressed air.

  Seventy Ingersoll-Rand rock drills, Nos. 1, 3¼, and 4.

  Two Rand quarry bars, cutting 10 ft. in length at one set-up, and
    mounted with No. 4 drill using a Z-bit.

_4._--_Transportation Plant._

  Twenty-one H. K. Porter locomotives, 10 by 16-in., and 36-in. gauge.

  Three Davenport locomotives, 9 by 16-in., and 36-in. gauge.

  One hundred and forty Western dump-cars, each of 4 cu. yd. capacity.

  One hundred and sixty-five flat cars, with iron skips, each of 4 cu.
    yd. capacity.

_5._--_Dock Plant._

  Four stiff-leg derricks on extension, having 35-ft. masts and 40-ft.
    booms, and each operated by a 60-h.p. Lambert, three-drum, electric,
    hoisting engine.

  One stiff-leg derrick, on the south side of the pier on the upper
    deck, with a 28-ft. mast operated by a three-drum Lambert engine
    and a 25-h.p. vertical boiler.

  One stiff-leg derrick, on the north side of the dock on the upper
    deck, used exclusively for bringing in brick, electric conduit,
    pipe, and other building material, operated when first erected by a
    three-drum, steam-driven, Lambert, hoisting engine. This engine was
    later changed to the derrick on the south side of the dock, and a
    motor-driven Lambert engine from that derrick was substituted.

  Eight electric telphers.

Ninth Avenue Twin-Tunnels Plant.

  One stiff-leg derrick, previously used in retaining-wall work.

  One Smith concrete mixer, 1 cu. yd. capacity, driven by attached air
    engine.

  Two cableways taken from the retaining-wall plant and used for mucking
    out the tunnels after the center pier had been built; driven by air
    supplied to the original engine.

  One Robbins belt conveyor, driven by a 30-h.p. engine run by air.

  Three 1-cu. yd. Hopple dump-cars.


CONSTRUCTION.

Ground was broken for work under the principal contract on July 9th,
1904, on which date the contractor began cutting asphalt for Trench No.
1 in 31st Street, and also began making a roadway from Ninth Avenue into
the pit just south of 32d Street.

_Excavation for Retaining Walls._--Two essentially different methods
were used in excavating for and building the retaining walls; one,
construction in trench, the other, construction on bench. In general,
the trench method was used wherever the rock on which the wall was to be
founded was 12 ft. or more below the surface of the street; or, what is
perhaps a more exact statement, as it includes the determining factor,
where the buildings adjoining the wall location were not founded on
rock.

In the trench method the base of the wall was staked out on the surface
of the ground, the required width being determined by the elevation of
the rock, as shown by the borings. The contractor then added as much
width as he desired for sheeting and working space, and excavated to a
depth of about 5 ft. before setting any timber. In some cases the depth
of 5 ft. was excavated before the cableway or derrick for the excavation
was erected, the wagons being driven directly into the excavation and
loaded by hand, but, usually, the cableway was first erected, and
buckets were used from the start. After the first 5 ft. had been
excavated, two sets of rangers and struts were set, the first in the
bottom of the excavation and the second at the level of the street
surface, supported by posts resting on the bottom rangers. The sheeting
was then set, and all voids back of it were filled with clean earth and
well tamped. The toe of the sheeting was kept level with the bottom of
the excavation until the ground-water was reached, after which it was
kept from 3 to 5 ft. ahead of the digging.

The sheeting used was 3-in., in variable widths; it was always tongued
and grooved on the side of the trench next to the buildings and in the
deeper excavations on both sides of the trench, and was driven by wooden
mauls above the ground-water level, but steam sheeting-drivers were used
below that elevation. Struts, rangers, and posts were generally 12 by
12-in.

Some exceedingly bad material was encountered in the deeper excavations,
beds of quicksand being passed through, varying in thickness from 1 to
18 ft., the latter, in 31st Street between Seventh and Eighth Avenues,
in the deepest excavation made. After encountering the fine sand in that
trench, no headway was made until a tight wooden cylinder was sunk
through the sand by excavating the material inside of it and heavily
weighting the shell with pig iron. When this cylinder had reached the
gravel, which lay below the sand, it was used as a sump, and the water
level was kept below the bottom of the excavation, which permitted good
progress. Sand continued to flow under the sheeting to such an extent,
however, that the front walls of four adjoining buildings were badly
cracked and had to be taken down and rebuilt. All the stoops along this
trench settled, and had to be repaired.

The bench method of excavating for the retaining wall was very simple,
and was used only where the rock lay near the surface and the adjoining
buildings were founded on it, the overlying material being in such case
dry, and consequently firm, little or no shoring was required. The
method was to extend the pit excavation to a width of 2 or 3 ft. beyond
the proposed back of the retaining wall, and to carry that width down to
the depth required for its base, below which the excavation was narrowed
to 1 ft. inside of the face of the wall and continued either before it
was built or subsequently.

_Retaining-Wall Construction._--The concrete walls were built in
sections 50 ft. in length, except where that spacing would bring an
expansion joint under a girder pocket or just on line with a tier of
struts, in which cases the section was shortened as required. Trenches
were never allowed to remain open at the full depth, the concreting
being started as soon after the necessary length of rock had been
uncovered as the forms and preliminary work for a section could be
prepared. Each section was a monolith, except in a few cases where
very heavy rains made it impossible to hold the laborers.

The various operations in building the concrete wall are shown on
Fig. 7. Guide-planks, "_a a_," Section "_A-A_," were securely spiked
to alternate tiers of struts for the length of the section, the face
of each guide-plank being set on line with the intended face of the
concrete wall, and 2-in. tongued-and-grooved spruce plank were laid
along the guide-plank to the height of the bottom strut and securely
braced from the front sheeting. A 4-in. brick wall was built
simultaneously on line with the back of the wall to the height of
the first step. Where the bottom strut was below that elevation, the
brickwork was left low at that immediate point and built up when the
strut was removed. The brick wall was then water-proofed on the side
toward the concrete, and loose laps of the water-proofing were allowed
to hang over the brickwork and at least 8 in. down the back. A 6-in.
vitrified pipe drain was then laid along the surface of the rock just
outside of the brick wall, the joints in the pipe being caulked with
oakum saturated in cement, and pointed with cement mortar above a line
1 in. below the horizontal diameter, the remainder of each joint being
left open. Cross-drains were laid from tees in the back drain to the
face of the wall at all low points in the rock and at least for every
25 ft. of wall length, the joints of these discharge pipes being caulked
and cemented throughout. The surface of the rock was then washed and
scraped clean, and was covered with about 1 in. of mortar, after which
the section was ready for concrete.

The building of monolithic sections in trenches required that the thrust
from one set of struts be taken by the concrete before the set above
could be removed, and necessarily caused slow progress, the rate at
which concrete was deposited being just sufficient to prevent one layer
from setting before the next layer above could be placed.

The concrete used was mixed in the proportions of 1 part of cement to
3 parts of sand and 6 parts of stone, in 2-bag batches, in ¾-yd. and
1-yd. Ransome portable mixers mounted with air-driven engines on the same
frame. These mixers were placed at the surface, and were charged with
barrows, the correct quantities of sand and stone for each batch being
measured in rectangular boxes previous to loading the barrows. The
concrete was discharged from the mixer into a hopper which divided into
two chutes, only one of which was used at a time, the concrete being
shoveled from the bottom of the chutes to its final position. Facing
mortar, 2 in. thick, was deposited simultaneously with the concrete, and
was kept separate from it by a steel diaphragm until both were in place,
when the diaphragm was removed and the two were spaded together. The
bottoms of the guide-planks were cut off just above the concrete as it
progressed, and, as soon as the wall had reached a strut at one end of
the section, that strut was removed, the form was built up to the next
strut, at front and back, and braced to the sheeting, so that, by the
time the entire length of the section had been carried up to the level
of the first line of struts, forms were ready at one end for the
succeeding layers. The layers of concrete never exceeded 8 in. in
height, and at times there were slight delays in the concreting while
the carpenters made ready the next lift of forms, but such delays were
rarely long enough to permit the concrete to take its initial set.

  [Illustration:
  Fig. 7.
  SKETCH SHOWING FORMS FOR, AND METHOD OF, CONCRETING RETAINING WALLS
  IN TRENCH.]

After a section of concrete had firmly set, both back and front forms
were removed, and the thrust from the sides of the trench was
transferred directly to the finished wall. The face of the wall was
rubbed with a cement brick to remove the marks of the plank, and was
then coated with a wash of thin cement grout. The water-proofing and
brick armor were then continued up the back of the wall, the spaces
between the lines of braces being first water-proofed and bricked, and
the braces transferred to the finished surface, after which the omitted
panels were completed. The water-proofing consisted of three layers of
Hydrex felt, of a brand known as Pennsylvania Special, and four layers
of coal-tar pitch. The pitch contained not less than 25% of carbon,
softened at 60° Fahr., and melted at a point between 96° and 106° Fahr.
The melting point was determined by placing 1 gramme of pitch on a lead
disk over a hole, 5/16-in. in diameter, and immersed in water which was
heated at the rate of 1° per min.; the temperature of the water at the
time the pitch ran through the hole was considered as the melting point.

In order to prevent the water-proofing from being torn at the joint
between sections when they contract from changes in temperature, a
vertical strip of felt, 6 in. wide, was pitched over each joint, lapping
3 in. on each concrete section. The back of this strip was not pitched,
but was covered with pulverized soapstone, so that the water-proofing
sheet was free from the wall for a distance of 3 in. on either side of
each joint.

Concreting was continued during the severest weather, one section being
placed when the thermometer was 5° above zero. When the thermometer was
below the freezing point both sand and stone were heated by wood fires
in large pipes under the supply piles; the temperature of the mix was
taken frequently, and was kept above 40 degrees. Numerous tests made
while the work was in progress showed that, while the temperature fell
slightly soon after the concrete was deposited, it was always from 2° to
5° higher at the end of 2 hours. The face and back of the concrete were
prevented from freezing by a liberal packing of salt hay just outside
the forms.

A vertical hog trough, 24 in. wide and 9 in. deep, was placed in one
end of each section, for its full height below the bridge seat, into
which the next section keyed, and, when the temperature at the time
of concreting was below 50° Fahr., a compression joint was formed by
placing a strip of heavy deadening felt, 2 ft. wide, on the end of the
completed section next to the face and covering the remainder of the
end with two ply of the felt and pitch water-proofing; the one ply of
deadening felt near the face was about the same thickness as the two ply
of water-proofing, and was used to prevent the pitch from being squeezed
out of the joint to the face of the wall.

The excavation for the retaining walls in 31st and 33d Streets were in
all cases made of sufficient width to receive the sewers, which were
laid as soon as the back-fill, carefully rammed and puddled, had reached
the proper elevations; the back-filling was then completed, and the gas
and water mains were afterward laid in separate trenches.

  [Illustration:
  Fig. 8.
  SKETCH SHOWING FORMS AND BRACING FOR NINTH AVENUE WALL]

The sections of concrete built in trench varied in height from 13 to
59 ft. from the base to the top of the back wall. With the exception of
the Seventh Avenue wall, 50 ft. in height, and the Ninth Avenue wall,
62 ft. in height, none of those sections constructed by the bench
method was more than 14 ft. The forms and bracing for these walls were
substantially the same, except that the low walls were built in lengths
of approximately 50 ft., while the forms for the Seventh and Ninth
Avenue walls were only 20 ft. long.

The forms and bracing for the Ninth Avenue walls are shown on Fig. 8.
These forms were built in one piece and moved ahead from section to
section, and they were firmly braced from the bottom with raker braces
to a point 36 ft. above the base, the upper part being held in place by
¾-in. bolts passed through the forms and anchored by cables to bolts
grouted into the rock behind.

After the forms had been set and braced, an 8-in. brick wall was laid
up the face of the rock, containing a vertical line of three-cell hollow
tile block every 5 ft. of length, and laid to conform as nearly as
possible to the face of the rock, all voids being filled with broken
stone. Water-proofing, similar to that described for the walls in the
trench, was then applied to the brick and tile wall for the full height,
and firmly braced to the front forms, the braces being removed as the
concrete reached them. The concrete was mixed at the street level and
deposited through chutes, as described previously.

Tables 1, 2, and 3 show the quantity of cement used in each section of
retaining wall, and give figures by which the quantities of other
materials may be determined.

_Pit Excavation._--The pit excavation during the horse-and-truck period
was largely preparatory work done to get the excavation in good shape
for handling spoil trains after Pier No. 72 and the trestle approach
were finished. This required an open cut from Ninth to Seventh Avenues
at a sufficient depth below the sewers and other substructures in the
avenues to clear a locomotive, and wide enough for both running and
loading tracks, also the building of the cast-iron sewer in Eighth
Avenue across the entire excavation, with enough of the temporary
bridging to support it. The building of the trestle in Eighth Avenue
was essentially a part of the pit excavation, as the progress of one
depended greatly on that of the other.

Excavation was commenced on July 12th, 1904, for the crossing under
Ninth Avenue, and in the pit east of Ninth Avenue along 32d Street. The
line chosen for the opening cut was down the center of the pit, as it
was not safe to excavate near the bounding streets until after the
completion of the enclosing retaining wall. The excavation was started
by hand, but three 70-ton Bucyrus steam shovels were put to work as soon
as they could be delivered, the first on July 25th and the third on
September 12th. The excavated material was loaded by the shovels on
end-dump wagons, each having a capacity of 2 cu. yd., and was conveyed
in them to the dumping board at 35th Street. The average number of teams
was 135, 10% being snatch teams to pull the wagons out of the pit and to
assist them up the runway at the dumping board. The teams averaged only
seven trips per day of 10 hours, considerable delay being caused by the
trains of the New York Central Railroad at Eleventh Avenue. The number
of teams was not sufficient, therefore, to keep the three shovels busy
when they were all in good digging, but the dumping board was taxed to
accommodate that number, and little would have been gained by increasing
it. The digging was very good during this period, practically no rock
being encountered, and the building foundations were too light to
present any obstacle to such powerful shovels. The capacity of their
dippers was 3½ cu. yd., so that one dipperful meant one truck loaded and
running over. The output from August to November, inclusive, averaged
40,000 cu. yd. per month; one shift only was worked per day, and
although the quantity was not large for three such powerful shovels, it
was large to truck through the streets, and required that one team pass
a given point every 18 sec. At the end of November the opening up of
the pit had been accomplished, considerable rock had been stripped
near Ninth Avenue, and the streets had become so icy that the cost of
transportation was practically doubled; work in the pit, therefore, was
much curtailed, and amounted to continuous work for one shovel from that
time until the end of the period, May 22d, 1905, when Pier No. 72 was
put in service and transportation by train began. Figs. 2 and 3, Plate
LVI, show the condition of the pit east and west of Eighth Avenue,
respectively, on that date.

  [Illustration:
  Fig. 9.
  SKETCH SHOWING TYPICAL BENT OF TRESTLE SUPPORTING EIGHTH AVENUE]

The work of excavating for and building the temporary street bridge,
a typical bent and bracing for which are shown on Fig. 9, and the
cast-iron sewer and water mains in Eighth Avenue, was commenced on
September 3d, 1904. The trestle was a double-decked structure of yellow
pine, with 10 by 10-in. posts and sills, 10 by 14-in. intermediate and
top caps, and 2 by 10-in. longitudinal and cross-braces. The trestle was
further stiffened longitudinally by four lines of 8 by 10-in. struts,
butted between the intermediate caps, and held in position by 2 by 8-in.
splice-plates resting on top of them. The intermediate caps were at an
elevation of 15 ft. below the surface of the street, and above that line
the longitudinal bracing was continuous, while below it the bents were
braced in pairs, the bracing being omitted from every second bay. Below
the intermediate cap the bents were uniform for the entire width of the
trestle, but the top cap was not continuous, being 5 ft. below the
surface under the trolley tracks, and only 18 in., the depth of
stringers and planking, beyond. The stringers under the trolley tracks
were 8 by 16-in. yellow pine, spaced three to a track, and those for the
driveway were 6 by 14-in., spaced 1 ft. 6 in. on centers, the planking
being 4-in. yellow pine.

The first step in the construction was to excavate a trench 15 ft. wide
on the west side of the street, the east side of the trench being 4 ft.
west of the westernmost trolley rail. While this work was in progress,
all vehicular traffic was turned to that part of the avenue east of the
westerly trolley rail. The trench was sheeted and timbered, and carried
to a depth sufficient to receive the intermediate cap. That portion of
the bent from the bottom of the intermediate cap to the bottom of the
top cap was then erected for the width of the trench, after which the
60-in. cast-iron sewer and the 48-in. water main were laid in position
and caulked. The top cap, stringers, and planking were then laid, for
the full width of the trestle west of the trolley tracks. This work was
finished and the sewage turned into the new sewer in April, 1905.

As the planking was laid west of the trolley tracks, traffic was turned
to that side of the street, and the material east of the tracks was
excavated to its natural slope. Trenches were then dug under the tracks
on the line of the bents, and the caps were set in position on blocking.
The material between these trenches was then removed, the tracks being
supported meanwhile by blocking at least every 6 ft., and the stringers
and planking were shoved into place. Excavation was next made between
the caps to a depth of about 5 ft. below them, needle-beams being placed
under the caps, one or two at a time, and supported on posts erected in
these excavations; the material on line of the bents was excavated to
the depth of the intermediate caps, which were then set, together
with the posts and bracing for the upper deck of the structure. This
operation was repeated for the lower deck, about 10 ft. being gained for
each change of posts, and three shifts, therefore, were required.

At the beginning of the train-transportation period, May 22d, 1905, two
shifts of 10 hours each were inaugurated, and the earth was handled at
the rate of from 85,000 to 90,000 cu. yd. per month; but, by the end of
August, when a little more than 60% of the total earth had been disposed
of, the rock began to interfere very greatly with the progress. The
strike of the rock was almost directly north and south, and its surface
formed broken ridges running in that direction, with deep valleys
between. The dip was almost vertical near Ninth Avenue, and about 70°
toward the west near Seventh Avenue. This condition made it necessary to
turn the shovels parallel to the ridges in order to strip the rock for
drilling; and, as the ridges were very broken, the shovels continued to
bump into them on all occasions, making it necessary to move back and
start other cuts or stand and wait for the rock to be drilled and
blasted. One small Vulcan steam shovel, with vertical boiler and ¾-cu.
yd. dipper, had been brought on the work to be used in stripping rock,
and was moved from place to place so much more easily than the large
ones that an Ohio shovel of the same general type was purchased in
October, and thereafter the stripping was done largely by the two small
shovels and by hand, the large shovels being used almost exclusively in
handling rock.

The drilling necessary to remove the rock was very large in amount and
also per yard excavated. In order not to damage the retaining walls and
the rock underlying them, holes spaced at 5-in. centers were drilled
1 ft. away from the face of the walls and on the same batter. These
breaking holes alone amounted to a total of 210,000 lin. ft., or 1 ft.
of hole for each 3½ cu. yd. of rock excavated; and the regulations of
the Bureau of Combustibles, which prevented springing, caused the
blasting holes to be placed very close together and required a total of
about 420,000 lin. ft., making 630,000 ft. If to this is added the block
holes, for some of the rock broke very large, it will show at least
1 ft. of drill hole for each cubic yard of rock excavated, about ten
times the average on general railroad work.

  [Transcriber's Note:
  The three numbered Tables were originally printed at full width, with
  columns (1)-(13) displayed in a single row.]

TABLE 1a.--Record of Retaining-Wall Sections, Terminal Station.

West Thirty-first Street from Seventh Avenue to Ninth Avenue.

 (1) Section No.
 (2) Stations.
 (3) Contents of section, in cubic yards.
 (4) Barrels of cement used for facing.
 (5) Cubic yards of facing mortar equivalent.
 (6) Barrels of cement used for bed mortar.
 (7) Cubic yards of bed mortar equivalent.
 (8) Cubic yards of embedded stone.

    (1)      (2)            (3)     (4)     (5)     (6)    (7)     (8)
   _____________________________________________________________________
  |  1   {165 + 05.8} |          |       |       |       |      |       |
  |      {165 + 66.0} |   617.48 | 17.50 |  5.95 |  ...  | ...  |  ...  |
  |  2   {165 + 66.0} |          |       |       |       |      |       |
  |      {165 + 95.4} |   233.96 | 10.25 |  3.49 |  ...  | ...  |  ...  |
  |  3   {165 + 95.4} |          |       |       |       |      |       |
  |      {166 + 41.2} |   355.20 | 24.50 |  8.34 |  ...  | ...  |  ...  |
  |  4   {171 + 03.4} |          |       |       |       |      |       |
  |      {171 + 53.4} |   309.29 | 67.50 | 23.00 |  ...  | ...  |  ...  |
  |  5   {177 + 44.0} |          |       |       |       |      |       |
  |      {177 + 94.0} |   109.62 | 30.25 | 10.30 |  ...  | ...  |  ...  |
  |  6   {171 + 53.4} |          |       |       |       |      |       |
  |      {171 + 83.0} |   246.35 | 27.75 |  9.44 |  ...  | ...  |  ...  |
  |  7   {166 + 41.2} |          |       |       |       |      |       |
  |      {166 + 79.0} |   644.12 | 77.50 | 26.37 |  ...  | ...  |  ...  |
  |  8   {171 + 83.0} |          |       |       |       |      |       |
  |      {172 + 12.0} |   394.43 | 63.75 | 21.69 |  ...  | ...  |  ...  |
  |  9   {166 + 79.0} |          |       |       |       |      |       |
  |      {167 + 20.5} |   974.58 |103.75 | 35.30 |  2.50 | 0.85 |  7.96 |
  | 10   {170 + 16.6} |          |       |       |       |      |       |
  |      {170 + 58.6} |   767.34 | 92.50 | 31.48 |  2.75 | 0.94 |  ...  |
  | 11   {170 + 58.6} |          |       |       |       |      |       |
  |      {171 + 03.4} |   599.17 | 77.00 | 26.20 | 10.25 | 3.49 |  ...  |
  | 12   {167 + 20.5} |          |       |       |       |      |       |
  |      {167 + 43.9} |   535.28 | 50.50 | 17.18 |  2.00 | 0.68 |  4.00 |
  | 13   {175 + 18.5} |          |       |       |       |      |       |
  |      {175 + 61.8} |   553.04 | 62.00 | 21.10 |  5.25 | 1.79 |  ...  |
  | 14   {177 + 02.9} |          |       |       |       |      |       |
  |      {177 + 44.0} |   305.12 | 49.25 | 16.76 |  4.50 | 1.53 |  ...  |
  | 15   {175 + 61.8} |          |       |       |       |      |       |
  |      {176 + 91.7} |   429.88 | 50.00 | 17.01 |  1.50 | 0.51 |  ...  |
  | 16   {176 + 62.5} |          |       |       |       |      |       |
  |      {177 + 02.9} |   675.64 | 77.50 | 26.37 |  6.25 | 2.13 |  ...  |
  | 17   {174 + 04.5} |          |       |       |       |      |       |
  |      {174 + 29.6} |   162.98 | 29.00 |  9.87 |  3.50 | 1.19 |  ...  |
  | 18   {175 + 91.7} |          |       |       |       |      |       |
  |      {176 + 21.5} |   698.88 | 46.25 | 15.72 |  4.50 | 1.53 | 15.86 |
  | 19   {176 + 21.5} |          |       |       |       |      |       |
  |      {176 + 62.5} | 1,166.79 | 81.50 | 27.73 |  4.00 | 1.36 | 34.96 |
  | 20   {167 + 43.9} |          |       |       |       |      |       |
  |      {167 + 92.6} |   975.53 | 95.75 | 32.58 |  3.25 | 1.11 | 36.99 |
  | 21   {172 + 12.0} |          |       |       |       |      |       |
  |      {172 + 45.2} |   271.48 | 31.75 | 10.80 |  2.50 | 0.85 |  8.65 |
  | 22   {168 + 41.3} |          |       |       |       |      |       |
  |      {168 + 72.6} |   316.30 | 44.00 | 14.97 |  5.25 | 1.79 |  7.18 |
  | 23   {173 + 63.6} |          |       |       |       |      |       |
  |      {174 + 04.5} |   529.33 | 54.75 | 18.63 |  4.75 | 1.62 |  1.25 |
  | 24   {167 + 92.6} |          |       |       |       |      |       |
  |      {168 + 41.3} | 1,010.64 | 66.00 | 22.46 |  5.50 | 1.87 | 10.16 |
  | 25   {173 + 21.2} |          |       |       |       |      |       |
  |      {173 + 63.6} |   675.21 | 77.75 | 26.46 |  2.50 | 0.85 | 12.00 |
  | 26   {164 + 72.5} |          |       |       |       |      |       |
  |      {165 + 05.8} |   458.22 | 40.00 | 13.61 |  5.50 | 1.87 | 22.37 |
  | 27   {172 + 81.9} |          |       |       |       |      |       |
  |      {173 + 21.2} |   409.43 | 35.00 | 11.91 |  9.75 | 3.31 |  4.64 |
  | 28   {164 + 27.6} |          |       |       |       |      |       |
  |      {164 + 72.5} |   658.46 | 72.00 | 24.50 |  1.50 | 0.51 | 16.40 |
  | 29   {172 + 45.2} |          |       |       |       |      |       |
  |      {172 + 81.9} |   345.89 | 30.25 | 10.29 |  5.00 | 1.70 |  1.62 |
  | 31   {174 + 78.0} |          |       |       |       |      |       |
  |      {175 + 18.5} |   507.50 | 35.75 | 12.17 |  3.00 | 1.02 | 17.09 |
  | 32   {174 + 29.6} |          |       |       |       |      |       |
  |      {174 + 78.0} |   396.99 | 43.75 | 14.89 |  1.75 | 0.60 |  6.50 |
  | 43   {177 + 94.0} |          |       |       |       |      |       |
  |      {178 + 44.1} |   194.07 | 30.00 | 10.21 |  2.00 | 0.68 |  8.35 |
  | Pier {168 + 72.6} |          |       |       |       |      |       |
  |      {168 + 81.1} |   106.52 |  ...  |  ...  |  ...  | ...  |  ...  |
  | 76   {178 + 44.1} |          |       |       |       |      |       |
  |      {178 + 94.1} |   136.32 | 12.75 |  4.34 |  4.75 | 1.62 |  ...  |
  | 79   {178 + 94.1} |          |       |       |       |      |       |
  |      {179 + 44.1} |   118.07 |  9.00 |  3.06 |  8.50 | 1.19 |  ...  |
  | 82   {179 + 44.1} |          |       |       |       |      |       |
  |      {179 + 93.7} |   126.12 |  6.50 |  2.21 |  2.50 | 0.85 |  ...  |
  | 84   {179 + 93.7} |          |       |       |       |      |       |
  |      {180 + 44.2} |   126.77 |  6.75 |  2.30 |  2.25 | 0.77 |  ...  |
  | 86   {180 + 44.2} |          |       |       |       |      |       |
  |      {180 + 93.6} |   162.48 |  8.00 |  2.72 |  2.75 | 0.94 |  ...  |
  | 90   {180 + 93.6} |          |       |       |       |      |       |
  |      {181 + 17.9} |    92.52 |  4.00 |  1.36 |  1.00 | 0.34 |  ...  |
  |___________________|__________|_______|_______|_______|______|_______|

TABLE 1b.--Record of Retaining-Wall Sections, Terminal Station.

West Thirty-first Street from Seventh Avenue to Ninth Avenue.

 (1) Section No.
 (2) Stations.
 (9) Cubic yards of concrete in section (net).
(10) Barrels of cement used in concrete.
(11) Barrels of cement per cubic yard of concrete.
(12) Concrete started.
(13) Concrete finished.

    (1)      (2)            (9)       (10)    (11)     (12)       (13)
   ______________________________________________________________________
  |  1   {165 + 05.8} |          |          |      |          |          |
  |      {165 + 66.0} |   611.53 |   731.50 | 1.20 |  11/4/04 | 11/20/04 |
  |  2   {165 + 66.0} |          |          |      |          |          |
  |      {165 + 95.4} |   230.47 |   277.25 | 1.20 | 11/21/04 | 11/27/04 |
  |  3   {165 + 95.4} |          |          |      |          |          |
  |      {166 + 41.2} |   346.86 |   398.25 | 1.15 | 11/26/04 |  12/3/04 |
  |  4   {171 + 03.4} |          |          |      |          |          |
  |      {171 + 53.4} |   286.29 |   360.50 | 1.26 |  12/2/04 | 12/10/04 |
  |  5   {177 + 44.0} |          |          |      |          |          |
  |      {177 + 94.0} |    99.32 |   120.75 | 1.22 | 12/28/04 | 12/30/04 |
  |  6   {171 + 53.4} |          |          |      |          |          |
  |      {171 + 83.0} |   236.91 |   292.50 | 1.23 |   1/2/05 |  1/11/05 |
  |  7   {166 + 41.2} |          |          |      |          |          |
  |      {166 + 79.0} |   617.75 |   737.00 | 1.19 |  1/13/05 |   2/4/05 |
  |  8   {171 + 83.0} |          |          |      |          |          |
  |      {172 + 12.0} |   372.74 |   420.75 | 1.13 |  1/14/05 |  1/28/05 |
  |  9   {166 + 79.0} |          |          |      |          |          |
  |      {167 + 20.5} |   930.47 | 1,066.25 | 1.14 |  2/18/05 |  3/13/05 |
  | 10   {170 + 16.6} |          |          |      |          |          |
  |      {170 + 58.6} |   734.92 |   852.50 | 1.16 |  1/31/05 |  2/25/05 |
  | 11   {170 + 58.6} |          |          |      |          |          |
  |      {171 + 03.4} |   569.48 |   689.75 | 1.21 |  3/11/05 |  3/23/05 |
  | 12   {167 + 20.5} |          |          |      |          |          |
  |      {167 + 43.9} |   513.42 |   611.75 | 1.19 |   3/9/05 |  3/26/05 |
  | 13   {175 + 18.5} |          |          |      |          |          |
  |      {175 + 61.8} |   530.15 |   630.50 | 1.19 |  3/15/05 |  3/29/05 |
  | 14   {177 + 02.9} |          |          |      |          |          |
  |      {177 + 44.0} |   286.83 |   340.25 | 1.19 |  3/26/05 |  3/31/05 |
  | 15   {175 + 61.8} |          |          |      |          |          |
  |      {176 + 91.7} |   412.36 |   472.50 | 1.15 |  3/28/05 |  4/14/05 |
  | 16   {176 + 62.5} |          |          |      |          |          |
  |      {177 + 02.9} |   647.14 |   788.00 | 1.22 |   4/1/05 |  4/17/05 |
  | 17   {174 + 04.5} |          |          |      |          |          |
  |      {174 + 29.6} |   151.92 |   182.50 | 1.20 |   5/3/05 |   5/6/05 |
  | 18   {175 + 91.7} |          |          |      |          |          |
  |      {176 + 21.5} |   665.77 |   801.00 | 1.20 |   5/9/05 |  5/19/05 |
  | 19   {176 + 21.5} |          |          |      |          |          |
  |      {176 + 62.5} | 1,102.74 | 1,354.50 | 1.23 |  5/15/05 |  5/28/05 |
  | 20   {167 + 43.9} |          |          |      |          |          |
  |      {167 + 92.6} |   904.85 | 1,012.75 | 1.12 |  5/25/05 |   6/3/05 |
  | 21   {172 + 12.0} |          |          |      |          |          |
  |      {172 + 45.2} |   251.18 |   311.50 | 1.24 |  5/29/05 |   6/3/05 |
  | 22   {168 + 41.3} |          |          |      |          |          |
  |      {168 + 72.6} |   292.36 |   338.75 | 1.16 |   6/5/05 |  6/10/05 |
  | 23   {173 + 63.6} |          |          |      |          |          |
  |      {174 + 04.5} |   507.83 |   587.25 | 1.16 |   6/5/05 |  6/13/05 |
  | 24   {167 + 92.6} |          |          |      |          |          |
  |      {168 + 41.3} |   976.15 | 1,038.75 | 1.07 |   6/8/05 |  6/21/05 |
  | 25   {173 + 21.2} |          |          |      |          |          |
  |      {173 + 63.6} |   635.90 |   776.25 | 1.22 |  6/16/05 |  6/24/05 |
  | 26   {164 + 72.5} |          |          |      |          |          |
  |      {165 + 05.8} |   420.37 |   532.00 | 1.26 |  6/23/05 |  6/28/05 |
  | 27   {172 + 81.9} |          |          |      |          |          |
  |      {173 + 21.2} |   389.57 |   450.00 | 1.16 |  6/27/05 |   7/7/05 |
  | 28   {164 + 27.6} |          |          |      |          |          |
  |      {164 + 72.5} |   617.05 |   726.25 | 1.18 |  6/29/05 |   7/7/05 |
  | 29   {172 + 45.2} |          |          |      |          |          |
  |      {172 + 81.9} |   332.28 |   384.00 | 1.16 |  7/11/05 |  7/19/05 |
  | 31   {174 + 78.0} |          |          |      |          |          |
  |      {175 + 18.5} |   477.22 |   567.50 | 1.19 |  7/29/05 |   8/6/05 |
  | 32   {174 + 29.6} |          |          |      |          |          |
  |      {174 + 78.0} |   375.00 |   434.25 | 1.16 |   8/5/05 |  8/12/05 |
  | 43   {177 + 94.0} |          |          |      |          |          |
  |      {178 + 44.1} |   174.83 |   219.75 | 1.26 |  11/9/05 | 11/12/05 |
  | Pier {168 + 72.6} |          |          |      |          |          |
  |      {168 + 81.1} |   106.52 |   144.00 | 1.35 |  12/6/06 |  12/8/06 |
  | 76   {178 + 44.1} |          |          |      |          |          |
  |      {178 + 94.1} |   130.36 |   142.50 | 1.09 |   7/8/07 |  7/10/07 |
  | 79   {178 + 94.1} |          |          |      |          |          |
  |      {179 + 44.1} |   113.82 |   129.50 | 1.14 |  7/15/07 |  7/16/07 |
  | 82   {179 + 44.1} |          |          |      |          |          |
  |      {179 + 93.7} |   123.06 |   131.75 | 1.07 |  7/22/07 |  7/23/07 |
  | 84   {179 + 93.7} |          |          |      |          |          |
  |      {180 + 44.2} |   123.70 |   133.50 | 1.08 |  7/26/07 |  7/27/07 |
  | 86   {180 + 44.2} |          |          |      |          |          |
  |      {180 + 93.6} |   158.82 |   167.00 | 1.05 |  7/30/07 |  7/31/07 |
  | 90   {180 + 93.6} |          |          |      |          |          |
  |      {181 + 17.9} |    90.82 |   115.00 | 1.27 |  8/18/08 |  8/18/08 |
  |___________________|__________|__________|______|__________|__________|

NOTE.--The number of cubic yards of crushed stone used in any section
can be found by multiplying the figure for that section in Column 10 by
0.7778.

The number of cubic yards of sand used in any section can be found by
multiplying: the sum of the figures for that section in Columns 4, 6,
and 10 by 0.3889.

  REMARKS.--Section No. 4. Amount of sand cut down on a part of this
    section on account of dust in stone.
  Section No. 8. O'Rourke stone used on this section, large and full of
    dust.
  Section No. 9. Stone crushed on the work used on this section, large
    and full of dust.
  Section No. 21. 1:3:5 mix was used in part of this section on account
    of stone being large.
  Section No. 24. Different sized stone was shipped on barge and mixed
    on the board for this section.
  Section No. 25. 1:3:5 mix used in a small part of this section on
    account of stone being large.
  Sections Nos. 76, 82, 84, and 86. Stone contained large amount of
    dust.

TABLE 2a.--Record of Retaining-wall Sections, Terminal Station.

West Thirty-third Street from Seventh Avenue to Ninth Avenue.

 (1) Section No.
 (2) Stations.
 (3) Contents of section, in cubic yards.
 (4) Barrels of cement used for facing.
 (5) Cubic yards of facing mortar equivalent.
 (6) Barrels of cement used for bed mortar.
 (7) Cubic yards of bed mortar equivalent.
 (8) Cubic yards of embedded stone.

    (1)    (2)            (3)     (4)     (5)     (6)    (7)     (8)
   ___________________________________________________________________
  | 30 {170 + 73.2} |          |       |       |       |      |       |
  |    {171 + 16.1} |   364.72 | 42.50 | 14.46 |  4.00 | 1.36 |  ...  |
  | 33 {178 + 48.7} |          |       |       |       |      |       |
  |    {178 + 84.1} |   180.40 | 29.50 | 10.04 |  3.50 | 1.19 |  ...  |
  | 34 {R 2 + 75.5} |          |       |       |       |      |       |
  |    {170 + 03.5} |   214.12 | 38.00 | 12.93 |  1.00 | 0.34 |  1.50 |
  | 35 {171 + 16.1} |          |       |       |       |      |       |
  |    {171 + 42.5} |   381.56 | 40.25 | 13.70 |  1.00 | 0.34 | 14.37 |
  | 36 {170 + 03.6} |          |       |       |       |      |       |
  |    {170 + 25.0} |   150.16 | 20.50 |  6.98 |  ...  | ...  |  6.25 |
  | 37 {171 + 42.5} |          |       |       |       |      |       |
  |    {171 + 91.3} |   869.40 | 59.50 | 20.25 |  4.50 | 1.53 | 44.96 |
  | 38 {171 + 91.3} |          |       |       |       |      |       |
  |    {172 + 19.2} |   233.49 | 22.75 |  7.74 |  2.75 | 0.94 | 14.45 |
  | 39 {179 + 27.2} |          |       |       |       |      |       |
  |    {179 + 64.2} |   255.39 | 32.00 | 10.89 |  3.00 | 1.02 |  9.05 |
  | 40 {170 + 25.0} |          |       |       |       |      |       |
  |    {170 + 73.2} |   500.73 | 44.25 | 15.06 |  1.00 | 0.34 | 29.64 |
  | 41 {169 + 50.8} |          |       |       |       |      |       |
  |    {R 2 + 75.5} |   215.93 | 28.25 |  9.61 |  2.00 | 0.68 |  ...  |
  | 42 {178 + 84.1} |          |       |       |       |      |       |
  |    {179 + 27.2} |   177.62 | 23.00 |  7.83 |  1.50 | 0.51 |  7.06 |
  | 44 {180 + 05.5} |          |       |       |       |      |       |
  |    {180 + 44.2} |   936.15 | 58.75 | 19.99 | 10.50 | 3.47 | 73.84 |
  | 45 {180 + 44.2} |          |       |       |       |      |       |
  |    {180 + 74.9} | 1,133.59 | 60.00 | 20.42 |  5.00 | 1.70 | 60.71 |
  | 46 {179 + 64.2} |          |       |       |       |      |       |
  |    {180 + 05.5} |   477.14 | 35.00 | 11.91 |  3.75 | 1.28 | 24.58 |
  | 47 {169 + 00.1} |          |       |       |       |      |       |
  |    {169 + 50.8} |   136.19 | 14.25 |  4.85 |  3.50 | 1.19 |  2.00 |
  | 48 {178 + 24.1} |          |       |       |       |      |       |
  |    {178 + 48.7} |   192.78 | 21.25 |  7.23 |  2.00 | 0.68 |  ...  |
  | 49 {177 + 81.1} |          |       |       |       |      |       |
  |    {178 + 24.1} |   241.51 | 25.25 |  8.59 |  2.50 | 0.85 |  1.33 |
  | 50 {168 + 03.6} |          |       |       |       |      |       |
  |    {168 + 45.6} |   405.61 | 25.50 |  8.68 |  4.00 | 1.36 | 36.10 |
  | 51 {177 + 38.4} |          |       |       |       |      |       |
  |    {177 + 81.1} |   100.54 | 12.75 |  4.34 |  3.00 | 1.02 |  0.78 |
  | 52 {168 + 45.6} |          |       |       |       |      |       |
  |    {168 + 80.1} |   181.96 | 19.00 |  6.47 |  1.00 | 0.34 |  9.03 |
  | 53 {168 + 80.1} |          |       |       |       |      |       |
  |    {169 + 00.1} |    41.32 |  3.50 |  1.19 |   ... |  ... |  ...  |
  | 55 {176 + 90.0} |          |       |       |       |      |       |
  |    {177 + 38.4} |    92.41 | 11.25 |  3.83 |  2.50 | 0.85 |  3.68 |
  | 56 {167 + 62.1} |          |       |       |       |      |       |
  |    {168 + 03.6} |   383.67 | 33.75 | 11.48 |  3.25 | 1.11 | 36.62 |
  | 59 {175 + 67.3} |          |       |       |       |      |       |
  |    {175 + 98.9} |   175.61 | 15.50 |  5.27 |  2.50 | 0.85 |  9.37 |
  | 60 {176 + 49.0} |          |       |       |       |      |       |
  |    {176 + 90.0} |    69.97 |  8.25 |  2.81 |  3.00 | 1.02 |  1.58 |
  | 61 {175 + 98.9} |          |       |       |       |      |       |
  |    {176 + 49.0} |   104.56 |  8.00 |  2.72 |  3.50 | 1.19 |  3.72 |
  | 64 {175 + 30.3} |          |       |       |       |      |       |
  |    {175 + 67.3} |   140.15 | 14.75 |  5.02 |  2.75 | 0.94 |  ...  |
  | 65 {174 + 85.4} |          |       |       |       |      |       |
  |    {175 + 30.3} |    80.66 |  9.00 |  3.06 |  2.50 | 0.85 |  ...  |
  | 66 {174 + 47.9} |          |       |       |       |      |       |
  |    {174 + 85.4} |    68.89 |  5.50 |  1.87 |  3.25 | 1.11 |  ...  |
  | 67 {174 + 21.1} |          |       |       |       |      |       |
  |    {174 + 47.9} |    60.14 |  3.00 |  1.02 |  2.00 | 0.68 |  0.92 |
  | 68 {167 + 12.3} |          |       |       |       |      |       |
  |    {167 + 62.1} |   379.94 | 23.50 |  8.00 |  5.00 | 1.70 | 19.34 |
  | 69 {173 + 85.6} |          |       |       |       |      |       |
  |    {174 + 21.1} |    77.43 |  6.50 |  2.21 |  3.00 | 1.02 |  ...  |
  | 70 {166 + 75.6} |          |       |       |       |      |       |
  |    {167 + 12.3} |   408.81 | 33.75 | 11.48 |  3.75 | 1.28 |  ...  |
  | 71 {173 + 46.5} |          |       |       |       |      |       |
  |    {173 + 85.6} |    85.92 |  8.25 |  2.81 |  1.75 | 0.60 |  ...  |
  | 74 {172 + 19.2} |          |       |       |       |      |       |
  |    {172 + 73.0} |   449.28 | 22.75 |  7.74 |  6.25 | 2.13 |  ...  |
  | 75 {172 + 73.0} |          |       |       |       |      |       |
  |    {173 + 24.0} |   502.20 | 27.25 |  9.27 |  7.00 | 2.38 |  ...  |
  | 77 {164 + 77.0} |          |       |       |       |      |       |
  |    {165 + 27.1} |   141.38 |  9.00 |  3.06 |  7.25 | 2.47 |  ...  |
  | 78 {168 + 83.4} |          |       |       |       |      |       |
  |    {169 + 18.3} |    63.35 |  3.00 |  1.02 |  1.50 | 0.51 |  ...  |
  | 80 {165 + 27.1} |          |       |       |       |      |       |
  |    {165 + 76.6} |   108.86 | 11.75 |  4.00 |  3.00 | 1.02 |  ...  |
  | 81 {168 + 45.6} |          |       |       |       |      |       |
  |    {168 + 83.4} |   210.97 | 13.00 |  4.42 |  6.25 | 2.13 |  ...  |
  | 83 {165 + 76.6} |          |       |       |       |      |       |
  |    {166 + 20.5} |   108.06 |  8.00 |  2.72 |  3.75 | 1.28 |  ...  |
  | 85 {166 + 20.5} |          |       |       |       |      |       |
  |    {166 + 64.6} |   107.52 |  9.00 |  3.06 |  2.25 | 0.76 |  ...  |
  | 87 {166 + 64.6} |          |       |       |       |      |       |
  |    {166 + 75.6} |    23.44 |  1.00 |  0.34 |  2.25 | 0.42 |  ...  |
  | 88 {164 + 26.3} |          |       |       |       |      |       |
  |    {164 + 77.0} |   317.72 | 24.00 |  8.17 |  2.25 | 0.76 |  ...  |
  | 89 {173 + 20.8} |          |       |       |       |      |       |
  |    {173 + 46.5} |    93.51 |  5.60 |  1.70 |  1.50 | 0.51 |  ...  |
  | 91 {180 + 74.9} |          |       |       |       |      |       |
  |    {180 + 92.7} |   141.40 | 17.50 |  5.96 |  ...  |  ... |  ...  |
  | 92 {180 + 92.7} |          |       |       |       |      |       |
  |    {181 + 28.8} |   118.93 | 19.00 |  6.46 |  ...  |  ... |  ...  |
  |_________________|__________|_______|_______|_______|______|_______|

TABLE 2b.--Record of Retaining-wall Sections, Terminal Station.

West Thirty-third Street from Seventh Avenue to Ninth Avenue.

 (1) Section No.
 (2) Stations.
 (9) Cubic yards of concrete in section (net).
(10) Barrels of cement used in concrete.
(11) Barrels of cement per cubic yard of concrete.
(12) Concrete started.
(13) Concrete finished.

   (1)    (2)            (9)        (10)   (11)    (12)       (13)
   ___________________________________________________________________
  |30 {170 + 73.2} |          |          |      |          |          |
  |   {171 + 16.1} |   348.90 |   391.00 | 1.12 | 7/20/05  | 7/26/05  |
  |33 {178 + 48.7} |          |          |      |          |          |
  |   {178 + 84.1} |   169.17 |   188.00 | 1.11 | 8/7/05   | 8/11/05  |
  |34 {R 2 + 75.5} |          |          |      |          |          |
  |   {170 + 03.5} |   199.35 |   217.25 | 1.09 | 8/14/05  | 8/19/05  |
  |35 {171 + 16.1} |          |          |      |          |          |
  |   {171 + 42.5} |   353.15 |   400.25 | 1.13 | 8/16/05  | 8/22/05  |
  |36 {170 + 03.6} |          |          |      |          |          |
  |   {170 + 25.0} |   136.93 |   133.75 | 0.98 | 8/19/05  | 8/22/05  |
  |37 {171 + 42.5} |          |          |      |          |          |
  |   {171 + 91.3} |   802.66 |   909.00 | 1.13 | 8/22/05  | 9/6/05   |
  |38 {171 + 91.3} |          |          |      |          |          |
  |   {172 + 19.2} |   210.36 |   238.50 | 1.13 | 8/24/05  | 8/27/05  |
  |39 {179 + 27.2} |          |          |      |          |          |
  |   {179 + 64.2} |   234.43 |   270.25 | 1.15 | 8/29/05  | 9/2/05   |
  |40 {170 + 25.0} |          |          |      |          |          |
  |   {170 + 73.2} |   455.69 |   525.75 | 1.15 | 9/11/05  | 9/15/05  |
  |41 {169 + 50.8} |          |          |      |          |          |
  |   {R 2 + 75.5} |   205.64 |   236.50 | 1.15 | 10/3/05  | 10/6/05  |
  |42 {178 + 84.1} |          |          |      |          |          |
  |   {179 + 27.2} |   162.22 |   194.75 | 1.20 | 10/9/05  | 10/11/05 |
  |44 {180 + 05.5} |          |          |      |          |          |
  |   {180 + 44.2} |   838.85 |   987.00 | 1.18 | 11/17/05 | 11/27/05 |
  |45 {180 + 44.2} |          |          |      |          |          |
  |   {180 + 74.9} | 1,050.86 | 1,206.00 | 1.15 | 12/13/05 | 12/23/05 |
  |46 {179 + 64.2} |          |          |      |          |          |
  |   {180 + 05.5} |   439.37 |   535.00 | 1.22 | 1/15/06  | 1/19/06  |
  |47 {169 + 00.1} |          |          |      |          |          |
  |   {169 + 50.8} |   128.15 |   150.50 | 1.17 | 4/4/06   | 4/6/06   |
  |48 {178 + 24.1} |          |          |      |          |          |
  |   {178 + 48.7} |   184.87 |   226.00 | 1.22 | 4/24/06  | 4/30/06  |
  |49 {177 + 81.1} |          |          |      |          |          |
  |   {178 + 24.1} |   230.74 |   274.00 | 1.19 | 5/21/06  | 5/24/06  |
  |50 {168 + 03.6} |          |          |      |          |          |
  |   {168 + 45.6} |   359.47 |   406.00 | 1.13 | 6/13/06  | 6/18/06  |
  |51 {177 + 38.4} |          |          |      |          |          |
  |   {177 + 81.1} |    94.40 |   112.00 | 1.19 | 6/20/06  | 6/21/06  |
  |52 {168 + 45.6} |          |          |      |          |          |
  |   {168 + 80.1} |   166.12 |   190.00 | 1.14 | 6/25/06  | 6/28/06  |
  |53 {168 + 80.1} |          |          |      |          |          |
  |   {169 + 00.1} |    40.13 |    44.50 | 1.11 | 6/29/06  | 6/29/06  |
  |55 {176 + 90.0} |          |          |      |          |          |
  |   {177 + 38.4} |    84.05 |    98.25 | 1.17 | 8/17/06  | 8/18/06  |
  |56 {167 + 62.1} |          |          |      |          |          |
  |   {168 + 03.6} |   334.46 |   383.50 | 1.14 | 8/28/06  | 9/1/06   |
  |59 {175 + 67.3} |          |          |      |          |          |
  |   {175 + 98.9} |   160.12 |   186.00 | 1.16 | 10/15/06 | 10/16/06 |
  |60 {176 + 49.0} |          |          |      |          |          |
  |   {176 + 90.0} |    64.56 |    75.00 | 1.16 | 10/17/06 | 10/18/06 |
  |61 {175 + 98.9} |          |          |      |          |          |
  |   {176 + 49.0} |    96.93 |   108.00 | 1.11 | 10/19/06 | 10/20/06 |
  |64 {175 + 30.3} |          |          |      |          |          |
  |   {175 + 67.3} |   134.19 |   161.50 | 1.20 | 11/21/06 | 11/22/06 |
  |65 {174 + 85.4} |          |          |      |          |          |
  |   {175 + 30.3} |    76.75 |    92.75 | 1.21 | 12/14/06 | 12/15/06 |
  |66 {174 + 47.9} |          |          |      |          |          |
  |   {174 + 85.4} |    65.91 |    83.50 | 1.27 | 12/18/06 | 12/18/06 |
  |67 {174 + 21.1} |          |          |      |          |          |
  |   {174 + 47.9} |    57.52 |    67.50 | 1.17 | 12/21/06 | 12/21/06 |
  |68 {167 + 12.3} |          |          |      |          |          |
  |   {167 + 62.1} |   350.90 |   412.50 | 1.17 | 1/2/07   | 1/6/07   |
  |69 {173 + 85.6} |          |          |      |          |          |
  |   {174 + 21.1} |    74.20 |    91.00 | 1.23 | 1/29/07  | 1/30/07  |
  |70 {166 + 75.6} |          |          |      |          |          |
  |   {167 + 12.3} |   396.05 |   468.50 | 1.18 | 4/2/07   | 4/10/07  |
  |71 {173 + 46.5} |          |          |      |          |          |
  |   {173 + 85.6} |    82.51 |    95.75 | 1.16 | 4/17/07  | 4/19/07  |
  |74 {172 + 19.2} |          |          |      |          |          |
  |   {172 + 73.0} |   439.41 |   506.00 | 1.15 | 6/20/07  | 6/24/07  |
  |75 {172 + 73.0} |          |          |      |          |          |
  |   {173 + 24.0} |   490.55 |   579.00 | 1.18 | 7/8/07   | 8/25/07  |
  |77 {164 + 77.0} |          |          |      |          |          |
  |   {165 + 27.1} |   135.85 |   161.50 | 1.19 | 7/13/07  | 7/15/07  |
  |78 {168 + 83.4} |          |          |      |          |          |
  |   {169 + 18.3} |    61.82 |    73.00 | 1.18 | 7/13/07  | 7/14/07  |
  |80 {165 + 27.1} |          |          |      |          |          |
  |   {165 + 76.6} |   103.84 |   133.50 | 1.28 | 7/18/07  | 7/19/07  |
  |81 {168 + 45.6} |          |          |      |          |          |
  |   {168 + 83.4} |   204.42 |   255.75 | 1.25 | 7/20/07  | 7/23/07  |
  |83 {165 + 76.6} |          |          |      |          |          |
  |   {166 + 20.5} |   104.06 |   128.50 | 1.23 | 7/25/07  | 7/27/07  |
  |85 {166 + 20.5} |          |          |      |          |          |
  |   {166 + 64.6} |   103.70 |   144.50 | 1.39 | 7/29/07  | 7/30/07  |
  |87 {166 + 64.6} |          |          |      |          |          |
  |   {166 + 75.6} |    22.68 |    30.00 | 1.32 | 7/31/07  | 7/31/07  |
  |88 {164 + 26.3} |          |          |      |          |          |
  |   {164 + 77.0} |   308.79 |   370.00 | 1.20 | 8/8/07   | 8/11/07  |
  |89 {173 + 20.8} |          |          |      |          |          |
  |   {173 + 46.5} |    91.30 |   121.75 | 1.33 | 9/7/07   | 9/8/07   |
  |91 {180 + 74.9} |          |          |      |          |          |
  |   {180 + 92.7} |   135.44 |   203.50 | 1.50 | 11/18/07 | 11/20/0  |
  |92 {180 + 92.7} |          |          |      |          |          |
  |   {181 + 28.8} |   112.47 |   190.00 | 1.69 | 12/1/08  | 12/2/08  |
  |________________|__________|__________|______|__________|__________|

NOTE.--The number of cubic yards of crushed stone used in any section
can be found by multiplying the figure for that section in Column 10 by
0.7778.

The number of cubic yards of sand used in any section can be found by
multiplying the sum of the figures for that section in Columns 4, 6, and
10 by 0.3889.

  REMARKS.--Section No. 47. Part of this section was removed on account
    of damage done by blasting and was replaced by Section No. 78.
  Section No. 52. All of this section was removed on account of damage
    done by blasting and was replaced by Section No. 81.
  Section No. 53. All of this section was removed on account of damage
    done by blasting and was replaced by Sections Nos. 78 and 81.

TABLE 3a.--Record of Retaining Wall Sections.

 (1) Section No.
 (2) Stations.
 (3) Contents of section, in cubic yards.
 (4) Barrels of cement used for facing.
 (5) Cubic yards of facing mortar equivalent.
 (6) Barrels of cement used for bed mortar.
 (7) Cubic yards of bed mortar equivalent.
 (8) Cubic yards of embedded stone.

       Power-House.

   (1)     (2)          (3)     (4)     (5)    (6)    (7)     (8)
   ________________________________________________________________
  | A  {L 2 + 75.3} |        |       |       |      |      |       |
  |    {L 3 + 25.3} | 463.28 | 58.25 | 19.82 | 5.50 | 1.87 | 11.50 |
  | B  {L 3 + 25.3} |        |       |       |      |      |       |
  |    {L 3 + 74.9} | 114.78 | 23.00 |  7.83 | 1.75 | 0.60 |  1.50 |
  | C  {169 + 30.8} |        |       |       |      |      |       |
  |    {169 + 74.8} | 179.19 | 34.25 | 11.66 | 1.00 | 0.34 |  3.60 |
  | D  {169 + 74.8} |        |       |       |      |      |       |
  |    {170 + 28.8} | 114.38 | 27.25 |  9.27 | 0.25 | 0.09 |  0.07 |
  | E  {168 + 83.6} |        |       |       |      |      |       |
  |    {169 + 30.8} | 101.20 | 22.00 |  7.49 | 1.50 | 0.51 |  0.65 |
  | F  {L 2 + 78.2} |        |       |       |      |      |       |
  |    {L 3 + 19.6} | 358.80 | 39.50 | 13.44 | 0.75 | 0.26 |  9.50 |
  | G  {L 3 + 19.6} |        |       |       |      |      |       |
  |    {L 3 + 56.9} | 237.33 | 23.00 |  7.83 | 1.00 | 0.34 |  0.74 |
  | H  {L 3 + 56.9} |        |       |       |      |      |       |
  |    {168 + 83.5} |  25.55 |  6.25 |  2.13 | 0.75 | 0.26 |  ...  |
  |_________________|________|_______|_______|______|______|_______|

       Seventh Avenue.
   ________________________________________________________________
  | 54 {164 + 27.6} |        |       |       |      |      |       |
  |    {L 2 + 32.0} | 764.48 | 69.75 | 23.74 | 3.00 | 1.02 |  ...  |
  | 57 {L 2 + 10.3} |        |       |       |      |      |       |
  |    {L 2 + 32.0} | 533.06 | 34.00 | 11.57 | 2.25 | 0.77 |  ...  |
  | 58 {L 1 + 87.1} |        |       |       |      |      |       |
  |    {L 2 + 10.3} | 544.54 | 32.25 | 10.97 | 2.00 | 0.68 |  9.80 |
  | 62 {L 1 + 87.1} |        |       |       |      |      |       |
  |    {L 1 + 64.4} | 575.67 | 30.00 | 10.21 | 3.00 | 1.02 |  6.20 |
  | 63 {L 1 + 42.4} |        |       |       |      |      |       |
  |    {L 1 + 64.4} | 607.01 | 30.50 | 10.38 | 2.50 | 0.85 |  3.79 |
  | 72 {L 1 + 42.4} |        |       |       |      |      |       |
  |    {L 1 + 19.6} | 631.97 | 30.00 | 10.21 | 1.75 | 0.60 |  1.18 |
  | 73 {L 1 + 19.6} |        |       |       |      |      |       |
  |    {L 0 + 97.0} | 573.33 | 25.25 |  8.59 | 0.25 | 0.08 |  2.48 |
  |_________________|________|_______|_______|______|______|_______|


TABLE 3b.--Record of Retaining Wall Sections.

 (1) Section No.
 (2) Stations.
 (9) Cubic yards of concrete in section (net).
(10) Barrels of cement used in concrete.
(11) Barrels of cement per cubic yard of concrete.
(12) Concrete started.
(13) Concrete finished.

       Power-House.

   (1)     (2)          (9)     (10)   (11)      (12)       (13)
   ________________________________________________________________
  | A  {L 2 + 75.3} |        |        |      |          |          |
  |    {L 3 + 25.3} | 430.09 | 482.75 | 1.12 |  5/18/05 |  5/25/05 |
  | B  {L 3 + 25.3} |        |        |      |          |          |
  |    {L 3 + 74.9} | 104.85 | 125.50 | 1.20 |  6/14/05 |  6/16/05 |
  | C  {169 + 30.8} |        |        |      |          |          |
  |    {169 + 74.8} | 163.59 | 183.00 | 1.12 |  7/10/05 |  7/13/05 |
  | D  {169 + 74.8} |        |        |      |          |          |
  |    {170 + 28.8} | 104.95 | 119.25 | 1.14 |  7/14/05 |  7/19/05 |
  | E  {168 + 83.6} |        |        |      |          |          |
  |    {169 + 30.8} |  92.55 | 107.25 | 1.16 |  7/26/05 |  7/28/05 |
  | F  {L 2 + 78.2} |        |        |      |          |          |
  |    {L 3 + 19.6} | 335.60 | 397.75 | 1.18 |  9/19/05 |  9/24/05 |
  | G  {L 3 + 19.6} |        |        |      |          |          |
  |    {L 3 + 56.9} | 228.42 | 278.00 | 1.22 |  9/26/05 |  9/29/05 |
  | H  {L 3 + 56.9} |        |        |      |          |          |
  |    {168 + 83.5} |  23.16 |  28.00 | 1.21 |  9/29/05 |  9/29/05 |
  |_________________|________|________|______|__________|__________|

       Seventh Avenue.
   ________________________________________________________________
  | 54 {164 + 27.6} |        |        |      |          |          |
  |    {L 2 + 32.0} | 739.72 | 907.50 | 1.23 |   8/6/06 |  8/15/06 |
  | 57 {L 2 + 10.3} |        |        |      |          |          |
  |    {L 2 + 32.0} | 520.72 | 610.75 | 1.17 |  9/10/06 |  9/15/06 |
  | 58 {L 1 + 87.1} |        |        |      |          |          |
  |    {L 2 + 10.3} | 523.09 | 588.25 | 1.12 |  9/24/06 |  9/28/06 |
  | 62 {L 1 + 87.1} |        |        |      |          |          |
  |    {L 1 + 64.4} | 538.24 | 639.50 | 1.19 | 10/24/06 | 10/29/06 |
  | 63 {L 1 + 42.4} |        |        |      |          |          |
  |    {L 1 + 64.4} | 581.99 | 678.50 | 1.17 |  11/5/06 | 11/11/06 |
  | 72 {L 1 + 42.4} |        |        |      |          |          |
  |    {L 1 + 19.6} | 619.98 | 719.50 | 1.16 |  4/25/07 |  4/30/07 |
  | 73 {L 1 + 19.6} |        |        |      |          |          |
  |    {L 0 + 97.0} | 562.18 | 685.75 | 1.22 |  5/13/07 |  5/18/07 |
  |_________________|________|________|______|__________|__________|

NOTE.--The number of cubic yards of crushed stone used in any section
can be found by multiplying the figure for that section in Column 10 by
0.7778. The number of cubic yards of sand used in any section can be
found by multiplying the sum of the figures for that section in Columns
4, 6, and 10 by 0.3889.

Channeling with a 10-ft quarry bar, carrying a No. 4 Ingersoll-Rand
drill with Z-bits, was attempted in place of the close drilling below
the walls, but, as the rock stood so nearly vertical and was full of
soft seams, very little could be accomplished, the average cut per day
of 10 hours, counting the time of moving and setting up, was only 4 sq.
ft., and, after a thorough trial, the bars were abandoned.

_Disposal._--The excavated material was hauled from the shovels to the
pier in 10-car trains. The cars were of three classes: 4-yd. Western
dump-cars, flat cars without skips, and flats carrying specially
designed steel skips having a capacity of 4 cu. yd. each. As far as
practicable, earth, and rock containing 1 cu. yd. or less, was loaded
on dumpers, medium-sized rock on the skips, and large rock on the bare
flats. As a steam shovel must pick up what is nearest to it first,
however, this classification could not always be adhered to, and many
large rocks were loaded into dumpers. Cars of this class which contained
no material too large to dump were run at once to the hoppers, and were
dumped and returned to the pit; others, together with the flat and skip
cars, were run down the incline to the derricks and telphers, where the
flats and skips were entirely unloaded, and the large rocks ware removed
from the dumpers, after which they were run to the hoppers and emptied.

The total quantity of excavated material handled at this pier from May
22d, 1905, to December 31st, 1908, amounted to 673,800 cu. yd. of earth
and 1,488,000 cu. yd. of rock, place measurement, equal to 3,203,400 cu.
yd., scow measurement; in addition to which 175,000 cu. yd. of crushed
stone and sand and 6,000 car loads of miscellaneous building material
were transferred from scows and lighters to small cars for delivery to
the Terminal work.

All the earth and 570,000 cu. yd. of the rock, place measurement, were
handled through the chutes, and the remainder of the rock, 918,000 cu.
yd., and all the incoming material by the derricks and telphers. In
capacity to handle material, one telpher was about equal to one derrick.
A train, therefore, could be emptied or a boat loaded under the bank of
eight telphers in one-fourth the time required by the derricks, of which
only two could work on one boat. The telphers, therefore, were of great
advantage where track room and scow berths were limited.

As noted in the list of contracts under which the work was executed,
the scows at both the 35th Street dumping board and Pier No. 72 were
furnished, towed, and the material finally disposed of, by Henry Steers,
Incorporated. During the same period, this contractor disposed of the
material excavated from both the Cross-town Tunnels, constructed by the
United Engineering and Contracting Company, and the tunnels under the
East River, constructed by S. Pearson and Son, Incorporated. As stated
in other papers of this series relating to the construction of those
tunnels, the material excavated by the United Engineering and
Contracting Company was delivered to barges at 35th Street and East
River and that by S. Pearson and Son, Incorporated, at two points, one
in Long Island City and the other at 33d Street and East River,
Manhattan.

The total number of cubic yards of material disposed of amounted to:

                                   Place measurement.   Total barge
                                   Earth.       Rock.   measurement.

  35th Street and North River     242,800      22,800      281,500
  Pier No. 72, North River        673,800   1,488,000    3,203,400
  From Cross-town Tunnels                                  570,400
  From Under-river Tunnels                                 402,500
                                                       -----------
                 Total                                   4,457,800
                                                       ===========

The material was delivered as follows:

  To the freight terminal of the Pennsylvania Railroad
    Company at Greenville, N.J.                          3,454,800
  To the Meadows Division of the Tunnel Line between
    Harrison, N.J., and the North River Portals            711,900
  To other points selected by the contractors              291,100
                                                         ---------
                 Total                                   4,457,800
                                                         =========

The handling of this large quantity of material required the loading of
from 10 to 20 scows per day (and for more than two years the average was
14), and, as the average time spent in one round trip was 3 1/3 days, a
fleet of more than 50 scows was required to keep all points supplied and
allow for a few to be out of service undergoing repairs.

All loaded scows were towed from the docks, with the ebb tide, to a
stake boat anchored in the bay about one mile off shore at Greenville;
and were taken from there to the different unloading points, as
required, by smaller tugs which also returned the empty scows to the
stake.

The unloading plants were similar at the different points, although that
at Greenville was much larger than the others. It included five land
dredges and eight traveling derricks of two types, one floating and the
other mounted on wheels and traveling on a track of 16-ft. gauge. The
derricks handled the large rock, which was loaded at Pier No. 72 by
derricks and telphers. They were of the ordinary A-frame type, and were
designed to handle 20 tons. They were operated by 9 by 10-in. Lidgerwood
double-drum and swinging-gear engines. The large rock was deposited by
the derricks either in the channels along which they worked or in the
fill along shore, without the use of cars. The land dredges were
equipped with a 60-ft. boom and a 2½-yd. Hayward bucket operated by a
14 by 18-in. double-drum Lidgerwood dredging engine. They loaded into
9-yd., standard-gauge, side-dump cars, built by the contractor, and
unloaded the scows to within about 1 ft. of the deck, a Hayward bucket
being unsuitable for closer work without greatly damaging the scows.
The material remaining was loaded by hand into skips which were handled
to the cars by small derricks, one of which was located at the rear of
each dredge. The cars were taken to the dump and returned by 25-ton,
standard-gauge, engines which had previously done service on the
Manhattan Elevated Railroad, but were spotted for loading by the engine
on the dredge.

In order to keep a record of the fleet of scows, which would show the
available supply at a glance, a board, 10 by 15 in., and covered with a
heavy sheet of ruled paper, was arranged as shown by Fig. 10. It was
divided into 12 vertical columns, the first of which was headed "Scows,"
and contained the name or number of each scow in service. The next four
columns denoted loading points, and were headed "Pier No. 72,"
"Thirty-third Street, East River," "Thirty-fifth Street, East River,"
and "Long Island City," respectively; the sixth column was headed
"Greenville," the seventh "Hackensack," the eighth "Passaic," and the
ninth "Governors Island," being unloading points, the tenth and
eleventh, "Stake Boat" and "Dry Dock," respectively, while the twelfth
was for "Extra pins," not in use. To indicate the condition of the
scows, small pins with colored heads were used; white indicated empty;
blue, working; black, loaded; red, being repaired; and a pearl-colored
pin, missing. Thus a white-headed pin opposite the number 6 in the
column headed Pier No. 72 indicated that scow No. 6 was lying at that
pier waiting to be placed in position for loading, whereas a
black-headed pin at the same point meant that the scow had received
its load and was ready to be towed.

BOARD RECORDING LOCATION AND CONDITION OF SCOWS

  [Transcriber's Note:
  This chart was originally presented as an illustration, Figure 10.
  It is shown here rotated from horizontal to vertical for readability.
  As in the original, only a partial board is shown; the number of Scows
  was at least 8.]

  +---------------------+-------+-------+-------+-------+-------+-------/
  |      Scows.         | H.S.  | H.S.  | H.S.  | H.S.  | H.S.  | H.S.  /
  |                     | No. 1 | No. 2 | No. 3 | No. 4 | No. 5 | No. 6 /
  +---------------------+-------+-------+-------+-------+-------+-------/
  | Loading Points      |       |       |       |       |       |       /
  +--+------------------+-------+-------+-------+-------+-------+-------/
  |  | Pier No. 72      |       |       |       |       |       |       /
  |  +------------------+-------+-------+-------+-------+-------+-------/
  |  | Thirty-third     |       |       |       |       |       |       /
  |  |   Street East R. |       |       |       |       |       |       /
  |  +------------------+-------+-------+-------+-------+-------+-------/
  |  | Thirty-fifth     |       |       |       |       |       |       /
  |  |   Street East R. |       |       |       |       |       |       /
  |  +------------------+-------+-------+-------+-------+-------+-------/
  |  | Long Island City |       |       |       |       |       |       /
  +--+------------------+-------+-------+-------+-------+-------+-------/
  | Unloading Points    |       |       |       |       |       |       /
  +--+------------------+-------+-------+-------+-------+-------+-------/
  |  | Greenville.      |       |       |       |       |       |       /
  |  +------------------+-------+-------+-------+-------+-------+-------/
  |  | Hackensack.      |       |       |       |       |       |       /
  |  +------------------+-------+-------+-------+-------+-------+-------/
  |  | Passaic.         |       |       |       |       |       |       /
  |  +------------------+-------+-------+-------+-------+-------+-------/
  |  | Governors Island.|       |       |       |       |       |       /
  +--+------------------+-------+-------+-------+-------+-------+-------/
  | Stake Boat.         |       |       |       |       |       |       /
  +---------------------+-------+-------+-------+-------+-------+-------/
  | Dry Dock.           |       |       |       |       |       |       /
  +---------------------+-------+-------+-------+-------+-------+-------/
  |                     |                                               /
  | Extra Pins.         |  Empty.    White Pins not in use placed here. /
  |                     |                                               /
  +---------------------+-----------------------------------------------/

The scows were all taken from the general service about the harbor; some
of them were practically new, while others had seen much service. They
were of two general types, truss-framed or bulkhead-framed; all were
flat-bottomed, with a rake of about 45° at bow and stern. The
truss-framed scows were built with a cross-truss every 10 to 15 ft., on
which rested, fore and aft, two classes of beams, main and intermediate.
The main beams were built of timbers ranging from 10 by 10 in. to 14 by
14 in., were scarfed at the joints, and trussed with the bottom logs.
The intermediate beams were of timbers varying from 6 by 6 in. to 10 by
12 in., had butt joints, and were dapped at the cross-trusses to give a
convex surface to the deck, which was built of 3-in. and 4-in. plank,
from 8 to 12 in. in width, running athwartship. The sides of the scows
of this class were spiked and bolted to trusses similar to those running
under the main beams. The bulkheaded boats had both sides and two
longitudinal bulkheads placed so as to divide the scow into three
sections of equal width, built of 8 by 8-in. or 10 by 10-in. timbers,
laid one upon the other, and bolted through from top to bottom. The
beams on these boats ran athwartship, rested on sides and bulkheads, and
ranged from 6 by 10-in. to 10 by 12-in., spaced 2 ft. apart, and dressed
to give a convex surface to the deck, which was usually 3 in., in some
cases 4 in., in thickness, and made up of narrow plank from 4 to 6 in.
in width.

  [Illustration:
  Fig. 11.
  DIAGRAM OF DECK SHOWING BAYS]

These boats had all been designed for lighter work than they were here
required to perform, and a large amount of breakage occurred from the
start. In order that the contractors for the excavation should be
unhampered as to method of loading, the contracts provided that they
should pay for all damage done to the scows in loading, other than
ordinary and usual wear and tear, all other damage being at the expense
of the contractor for the disposal. A rigid system of inspection was
necessary to determine and record properly the damage for which each
contractor was responsible; and, as much of the breakage could not be
noticed from the exterior, a thorough examination of the interior of
each scow was made before and after every loading. In order to keep
proper records, the bays of each scow, formed by the cross-trusses, were
numbered, beginning aft with number 1 and going forward to the bow, and
the longitudinal bays formed by the main beams were lettered, beginning
with "_A_" on the port side. A beam broken in "1-_A_," therefore, would
be an intermediate beam in the stern port corner bay, and a beam broken
in "10-_A-B_" would be a main beam at the bow end on the port side. The
underside of each plank was marked with a number beginning with 1 at the
stern and increasing by unity to the bow. Fig. 11 is a diagram of a scow
in accordance with this system. In addition to recording the date,
location, extent, and party responsible for each damage, in a book kept
for that purpose, the injured member was marked with paint, the color of
which indicated the party responsible. The repairs were made by the
contractor for the disposal of material, and the cost was assessed
according to the marking in the boat.

The careful inspection of the damage done to scows and the cost of their
repairs enables a fairly accurate statement to be made of the amount at
different points, and it is here given on the basis of cost of repairs
per cubic yard, barge measurement, of material handled.

                                            Cost, in cents
                                            per cubic yard.

  Repairs of damage done in loading material
        from the terminal site                   2.00
  Repairs of damage done in loading material
        from cross-town tunnels                  1.32
  Repairs of damage done in loading material
        from under-river tunnels                 1.77
  Repairs of damage done in transporting and
        unloading material from all points       1.81

The above figures do not include the expense due to scows which were
overturned or sunk while in the service, which amounted to 0.4 cent per
cubic yard, additional.

_Ninth Avenue Tunnels._--The two double-track tunnels under Ninth
Avenue, constructed to obtain 100 ft. of additional tail room on each
of four tracks, required an excavation 76 ft. wide, Fig. 12. The rock,
although fair, was not firm enough for so great a span, and, to obviate
the necessity of timbering, the center wall was built before excavating
for the full width. The dip of the rock at this point is almost 90°, and
to prevent blowing away the entire face in excavating for the tunnel,
the pit excavation was not carried west to the final face below the
springing line, a 10-ft. bench being left at that elevation. A top
heading 9 ft. high and 10 ft. wide was started above that bench and,
after penetrating about 10 ft., was widened to 20 ft. A cross-heading
was driven in each direction at the west end of the first heading; the
bench was then shot down, and the first 10 ft. of the longitudinal
heading was widened sufficiently to receive the center wall, Fig. 12.
After the middle wall had been concreted, any voids between its top
and the rock were grouted through pipes left for that purpose; the wall
was then protected by curtains of heavy round timber securely wired
together, and the remainder of the excavation was made by widening
the cross-headings toward the face. The muck was carried out by two
cableways, one on each side of the completed middle wall, each of which
was supported by a tower outside of the tunnel and a large hook-bolt
grouted into the rock at the inner end of the tunnel. Forms were built
for each tunnel complete, and the concrete was delivered by a belt
conveyor, running over the top of the lagging, and moved out as the
tunnel was keyed.

  [Illustration:
  Fig. 12.
  TERMINAL STATION SKETCH SHOWING TWO TRACK TUNNELS
  AT NINTH AVENUE AND THIRTY-THIRD STREET]


FOOTNOTES

  [1: Presented at the meeting of May 4th, 1910.]

  [2: Reproduced as Plate IX in the paper by Mr. Noble.]

  [Text reference for footnote 2:
  "one arm of the creek shown on General Viele's map of 1865"
  The article is ASCE 1152, The East River Division, available from
  Project Gutenberg as e-text 18065]

       *       *       *       *       *
           *       *       *       *
       *       *       *       *       *

[Errata:

Table 2a
  | 87 {166 + 64.6} |          |       |       |       |      |       |
  |    {166 + 75.6} |    23.44 |  1.00 |  0.34 |  2.25 | 0.42 |  ...  |
    _"2.25" is unclear; only ".25" is fully legible_]