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into the entrance lobby. The doorway is trimmed with cut granite and the lobby is finished with a
marble wainscoting.

The interior of the operating room is faced with a light, cream-colored pressed brick with an enameled
brick wainscoting, eight feet high, extending around the entire operating area; the wainscoting is white
except for a brown border and base. The offices, the toilets and locker rooms are finished and fitted with
materials in harmony with the high-class character of the building. The masonry-floor construction consists
of concrete reinforced with expanded metal, and except where iron or other floor plates are used, or where
tile or special flooring is laid, the floor is covered with a hard cement granolithic finish.

In the design of the interior arrangements, the value of a generous supply of stairways was appreciated,
in order that all parts of the structure might be made readily accessible, especially in the boiler house section.
In the boiler house and machinery portion of the plant the stairways, railings, and accessories are plainly but
strongly constructed. The main stairways are, however, of somewhat ornate design, with marble and other
trim work, and the railings of the main gallery construction are likewise of ornate treatment. All exterior
doors and trim are of metal and all interior carpenter work is done with Kalomein iron protection, so that
the building, in its strictest sense, will contain no combustible material.

The complete i2-unit power house will have six chimneys, spaced 108 feet apart on the longitudinal Chi//ltlC\S
center line of the boiler room, each chimney being 15 feet in inside diameter at the top, which is 225 feet
above the grate bars. Each will serve the twelve boilers included in the section of which it is the center,
these boilers having an aggregate of 72,000 square feet of heating surface. By these dimensions each
chimney has a fair surplus capacity, and it is calculated that, with economizers in the path of the furnace
gases, there will be sufficient draft to meet a demand slightly above the normal rating of the boilers.
To provide for overload capacity, as may be demanded by future conditions, a forced draft system will be
supplied, as described later.

As previously stated, the chimneys are all supported upon the steel structure of :he building at an ele-
vation of 76 feet above the basement floor and 63 feet above the grates. The supporting platforms are, in
each case, carried on six of the building columns (the three front columns of two groups of boilers
on opposite sides of the center aisle of the boiler room), and each platform is composed of single-web plate
girders, well braced and surmounted by a grillage of 2O-inch I-beams. The grillage is filled solidly with
concrete and flushed smooth on top to receive the brickwork of the chimney.

Each chimney is 162 feet in total height of brickwork above the top of the supporting platform, and each
chimney is 2^ feet square in the outside dimension at the base, changing to an octagonal form at a point 14
feet T, inches above the base. This octagonal form is carried to a height of 32 feet 6 inches above the base,
at which point the circular section of radial brick begins.

The octagonal base of the chimney is of hard-burned red brick three feet in thickness between the side of


the octagon and the interior circular section. The brick work is started from the top of the grillage platform



North River

with a steel channel curb, three feet in depth, through which two lines of steel rods are run in each direction,
thus binding together the first three feet of brickwork, and designed to prevent any flaking at the outside.
At a level of three feet above the bottom of the brickwork, a layer of water-proofing is placed over the
interior area and covered with two courses of brick, upon which are built diagonal brick walls, 4 inches thick,
12 inches apart, and about 18 inches in height. These walls are themselves perforated at intervals, and the
whole is covered with hand-burned terra-cotta blocks, thus forming a cellular air space, which communicates
with the exterior air and serves as an insulation against heat for the steelwork beneath. A single layer of
fire brick completes the flooring of the interior area, which is also flush with the bottom of the flue openings.

There are two flue openings, diametrically opposite, and 6 feet wide by 17 teet high to the crown of the
arched top. They are lined with fire brick, which joins the fire-brick lining of the interior of the shaft, this
latter being bonded to the red-brick walls to a point 6 feet below the top of the octagon, and extended above
for a height of 14 feet within the circular shaft, as an inner shell. The usual baffle wall is provided of fire
brick, 13 inches thick, extending diagonally across the chimney, and 4 feet above the tops of the flue openings.

Where the chimney passes through the roof of the boiler house, a steel plate and angle curb, which
clears the chimney by 6 inches at all points, is provided in connection with the roof framing. This is covered
by a hood flashed into the brickwork, so that the roof has no connection with or bearing upon the chimney.

At a point 4 feet 6 inches below the cap of the chimney the brickwork is corbeled out for several courses,
forming a ledge, around the outside of which is placed a wrought-iron railing, thus forming a walkway
around the circumference of the chimney top. The cap is of cast iron, surmounted by eight 3 x i-inch wrought-
iron ribs, bent over the outlet and with pointed ends gathered together at the center. The lightning
conductors are carried down the outside of the shaft to the roof and thence to the ground outside of the build-
ing. Galvanized iron ladder rungs were built in the brickwork, for ladders both inside and outside the shaft.

The chimneys, except for the octagonal red-brick base, are constructed of the radial perforated bricks.
The lightning rods are tipped with pointed platinum points about 18 inches long.

Exceptional facilities have been provided for the unloading of coal from vessels, or barges, which can be
brought to the northerly side of the recently constructed pier at the foot of West 58th Street. The pier was
specially built by the Department of Docks and Ferries and is 700 feet long and 60 feet wide.

The pier construction includes a special river wall across 58th Street at the bulkhead line through which
the condensing water will be taken from and returned to the river. Immediately outside the river wall and
beneath the deck of the pier, there is a system of screens through which the intake water is passed. On each
side where the water enters the screen chamber, is a heavy steel grillage; inside this is a system of fine screens
arranged so that the several screens can be raised, by a special machine, for the purpose of cleaning. The
advantages of a well-designed screening outfit has been appreciated, and considerable care has been exercised
to make it as reliable and effective as possible.

At each side ot the center of the pier, just below the deck, there are two discharge water conduits
constructed of heavy timber, to conduct the warm water from the condensers away from the cold water intakes
at the screens. Two water conduits are employed, in order that one may be repaired or renewed while using
the other; in fact, the entire pier is constructed with the view of renewal without interference in the operation
for which it was provided.



FROM the minute and specific description in Chapter III, a clear idea will have been obtained of
the power house building and its adjuncts, as well as of the features which not only go to make it
an architectural landmark, but which adapt it specifically for the vital function that it is called upon
to perform. We now come to a review and detailed description of the power plant equipment in its general
relation to the building, and "follow the power through" from the coal pile to the shafts of the engines or
steam turbines attached to the dynamos which generate current for power and for light.

The elements of the coal handling equipment comprise a movable electric hoisting tower with crushing (7fl<7/ il/ltl ~fs/l
and weighing apparatus a system of horizontal belt conveyors, with jo-inch belts, to carry the crushed and
weighed coal along the dock and thence by tunnel underground to the southwest corner of the power house;
a system of ^o-inch belt conveyors to elevate the coal a distance of I 10 feet to the top of the boiler house,
at the rate ot 250 tons per hour or more, it so desired, and a system of 2O-inch belt conveyors to distribute
it horizontally over the coal bunkers. These conveyors have automatic self reversing trippers, which
distribute the coal evenly in the bunkers. For handling different grades of coal, distributing conveyors are
arranged underneath the bunkers for delivering the coal from a particular bunker through gates to the
downtake hoppers in front of the boilers, as hereafter described.

The equipment tor removing ashes trom the boiler room basement and tor storing and delivering the
ashes to barges, comprises the following elements : A system ot tracks, 24 inches gauge, extending under
the ash-hopper gates in the boiler-house cellar and extending to an elevated storage bunker at the water front.
The rolling stock consists of 24 steel cars of 2 tons capacity, having gable bottoms and side dumping
doors. Each car has two four-wheel pivoted trucks with springs. Motive power is supplied by
an electric storage battery locomotive. The cars deliver the ashes to an elevating belt conveyor, which fills
the ash bunker. This will contain 1 ,000 tons, and is built of steel with a suspension bottom lined with
concrete. For delivering stored ashes to barges, a collecting belt extends longitudinally under the pocket,
being fed by eight gates. It delivers ashes to a loading belt conveyor, the outboard end of which is hinged
so as to vary the height of delivery and to fold up inside the wharf line when not in use.

The coal handling system in question was adopted because any serious interruption ot service would be
of short duration, as any belt, or part of the belt mechanism, could quickly be repaired or replaced. The
system also possessed advantages with respect to the automatic even distribution ot coal in the bunkers, by
means of the self reversing trippers. These derive their power trom the conveying belts. Each conveyor
has a rotary cleaning brush to cleanse the belt before it reaches the driving pulley and they are all driven by
induction motors.

The tower frame and boom are steel. The tower rolls on two rails along the dock and is self-



propelling. The lift is unusually short ; for the reason that the weighing apparatus is removed horizontally
to one side in a separate house, instead of lying vertically below the crusher. This arrangement reduces by
40 per cent, the lift of the bucket, which is of the clam-shell type of forty-four cubic feet capacity. The
motive power for operating the bucket is perhaps the most massive and powerful ever installed for such
service. The main hoist is directly connected to a 200 horse-power motor with a special system of
control. The trolley engine for hauling the bucket along the boom is also direct coupled to a multipolar

The receiving hopper has a large throat, and a steel grizzly in it which sorts out coal small enough for
the stokers and bypasses it around the crusher. The crusher is of the two-roll type, with relieving springs,
and is operated by a motor, which is also used for propelling the tower. The coal is weighed in duplex
two-ton hoppers.

Special attention has been given to providing for the comfort and safety of the operators. The cabs
have baywindow fronts, to enable the men to have an unobstructed view of the bucket at all times without
peering through slots in the floor. Walks and hand lines are provided on both sides of the boom for safe
inspection. The running ropes pass through hardwood slides, which cover the slots in the engine house
roof to exclude rain and snow.

This type of motive power was selected in preference to trolley locomotives for moving the ash cars,
owing to the rapid destruction of overhead lines and rail bonds by the action of ashes and water. The
locomotive consists of two units, each of which has four driving wheels, and carries its own motor and
battery. The use of two units allows the locomotive to round curves with very small overhangs, as
compared with a single-body locomotive. Curves of 12 feet radius can be turned with ease. The gross
weight of the locomotive is about five tons, all of which is available for traction.

The coal from the coal bunkers is allowed to flow down into the boiler room through two rows of
downtakes, one on each side of the central gangway or firing place. Each bunker has eight cast-iron outlets,
four on each side, and to these outlets are bolted gate valves tor shutting off the coal from the corresponding
downtakes. From these gates the downtakes lead to hoppers which are on the economizer floor, and from
these hoppers the lower sets of downtakes extend down to the boilers.

Just above the hoppers on the economizer floor the coal downtakes are provided with valves and chutes
to feed the coal, either into the hopper or into the distributing flight conveyor alongside of it. These
distributing conveyors, one corresponding with each row of downtakes, permits the feeding of coal from any
bunker or bunkers to all the boilers when desired. They are the ordinary type of flight conveyor, capable
of running in either direction and provided with gates in the bottom of the trough for feeding into the
several above mentioned hoppers. In order to eliminate the stresses that would develop in a conveyor of
the full length of the building, the conveyors are of half the entire length, with electric driving engines in
the center of each continuous line. The installation of this conveyor system, in connection with the coal
downtakes, makes it possible to carry a high-grade coal in some of the bunkers for use during periods of
heavy load and a cheaper grade in other bunkers for the periods of light load.

To provide means for shutting oft" the coal supply to each boiler, a small hopper is placed just over
each boiler, and the downtake feeding into it is provided with a gate at its lower end. Two vertical
downtakes extend down from the boiler hopper to the boiler room floor or to the stokers, as the case may





be, and they are hinged just below the boiler hopper to allow their being drawn up out of the way when
necessary to inspect the boiler tubes.

Wherever the direction of flow of the coal is changed, poke holes are provided in the downtakes to
enable the firemen to break any arching tendency of the coal in the downtakes. All parts of the downtakes
are of cast iron, except the vertical parts in front of the boilers, which are of wrought-iron pipe. These ver-
tical downtakes are 10 inches in inside diameter, while all others are 14 inches in inside diameter.

The main boiler room is designed to receive ultimately seventy-two safety water tube three drum boilers, ][fatn
each having 6,008 square feet of effective heating surface, by which the aggregate heating surface of the
boiler room will be 432,576 square feet.

There are fifty-two boilers erected in pairs, or batteries, and between each battery is a passageway five
feet wide. The boilers are designed for a working steam pressure of 225 pounds per square inch and for a
hydraulic test pressure of 300 pounds per square inch. Each boiler is provided with twenty-one vertical
water tube sections, and each section is fourteen tubes high. The tubes are ot lap welded, charcoal iron, 4
inches in diameter and iS feet long. The drums are 42 inches in diameter and 23 teet and 10 inches long.
All parts are of open-hearth steel ; the shell plates are ! liu of an inch thick and the drum head plates






11 /ifi inch, and in this respect
the thickness of material em-
ployed is slightly in excess of
standard practice. Another
advance on standard practice
is in the riveting of the circu-
lar seams, these being lap-
jomted and double riveted.
All longitudinal seams are
butt-strapped, inside and out-
side, and secured by six rows
of rivets. Manholes are only
provided for the front heads,
and each front head is pro-
vided with a special heavy
bronze pad, for making con-
nection to the stop and check
teed water valve.

The setting of the boiler
embodies several special fea-
tures which are new in boiler
erection. The boilers are set
higher up from the floor than
in standard practice, the center
of the drums being 19 feet above the floor line. This feature provides a higher combustion chamber, tor
either hand-fired grates or automatic stokers ; and tor inclined grate stokers the fire is carried well
up above the supporting girders under the side walls, so that these girders will not be heated by
proximity to the fire.

As regards the masonry setting, practically the entire inside surface exposed to the hot gases is lined
with a high grade of fire brick. The back of the setting, where the rear cleaning is done, is provided with
a sliding floor plate, which is used when the upper tubes are being cleaned. There is also a door at the floor
line and another at a higher level for light and ventilation when cleaning. Over the tubes arrangements have been
made for the reception of superheating apparatus without changing the brickwork. Where the brick walls
are constructed, at each side of the building columns at the front, cast-iron plates are erected to a height of 8
teet on each side of the column. An air space is provided between each cast-iron plate and the column, which
is accessible for cleaning from the boiler front; the object of the plates and air space being to prevent the
transmission of heat to the steel columns.

An additional feature of the boiler setting consists in the employment ot a soot hopper, back of each
bridge wall, by which the soot can be discharged into ash cars in the basement. The main ash hoppers are
constructed of ',-inch steel plate, the design being a double inverted pyramid with an ash gate at each in-




verted apex. The hoppers are well provided with stiffening angles and tees, and the capacity of each is
about 80 cubic feet.

In front of all the boilers is a continuous platform of open-work cast-iron plates, laid on steel beams, the
level of the platform being 8 feet above the main floor. The platform connects across the firing area,
opposite the walk between the batteries, and at these points this platform is carried between the boiler settings.
At the rear of the northerly row of boilers the platform runs along the partition wall, between the boiler
house and operating room and at intervals doorways are provided which open into the pump area. The
level of the platform is even with that of the main operating room floor, so that it may be freely used by the
water tenders and by the operating engineers without being obstructed by the firemen or their tools. The
platform in front of the boilers will also be used for cleaning purposes, and, in this respect, it will do away
with the unsightly and objectionable scaffolds usually employed for this work. The water tenders will also
be brought nearer to the water columns than when operating on the main floor. The feed-water valves will
be regulated from the platform, as well as the speed of the boiler-teed pumps.

Following European practice, each boiler is provided with two water columns, one on each outside
drum, and each boiler will have one steam gauge above the platform for the water tenders and one below the
platform tor the firemen. The stop and check valves on each boiler drum have been made specially heavy
for the requirements of this power house, and this special increase of weight has been applied to all the several
minor boiler fittings.

Hand-fired grates of the shaking pattern have been furnished for thirty-six boilers, and for each of these
grates a special lower front has been constructed. These fronts are of sheet steel, and the coal passes down
to the floor through two steel buckstays which have been enlarged for the purpose. There are three firing
doors and the sill of each door is 36 inches above the floor. The gate area of the hand-fired grates is 100
square feet, being 8 feet deep by 12 feet 6 inches wide.

The twelve boilers, which will receive coal from the coal bunker located between the fourth and fifth
chimneys, have been furnished with automatic stokers.

It is proposed to employ superheaters to the entire boiler plant.

The boiler-room ceiling has been made especially high, and in this respect the room differs from most
power houses of similar construction. The distance from the floor to the ceiling is 35 feet, and from the
floor plates over the boilers to the ceiling is 13 feet. Over each boiler is an opening to the economizer floor
above, covered with an iron grating. The height of the room, as well as the feature of these openings, and
the stairway wells and with the large extent of window opening in the south wall, will make the room light
and especially well ventilated. Under these conditions the intense heat usually encountered over boilers will
largely be obviated.

In addition to making provisions for the air to escape from the upper part of the boiler room, arrange-
ments have been provided for allowing the air to enter at the bottom. This inflow of air will take place
through the southerly row of basement windows, which extend above the boiler room floor, and through the
wrought-iron open-work floor construction extending along in the rear of the northerly row of boilers.

A noteworthy feature of the boiler room is the lo-ton hand-power crane, which travels along in the
central aisle through the entire length of the structure. This crane is used for erection and for heavy repair,
and its use has greatly assisted the speedy assembling of the boiler plant.



Blowers and

Air Ducts

Smoke Flues



Steam Piping

In order to burn the finer grades of anthracite coal in sufficient quantities to obtain boiler rating with
the hand-fired grates, and in order to secure a large excess over boiler rating with other coals, a system of
blowers and air ducts has been provided in the basement under the boilers. One blower is selected for every
three boilers, with arrangements for supplying all six boilers from one blower.

The blowers are i I feet high above the floor and 5 feet 6 inches wide at the floor line. Each blower
is direct-connected to a two crank 7 r 2 x 13 x 6 : 2-inch upright, automatic, compound, steam engine of the
self-enclosed type, and is to provide a sufficient amount of air to burn 10,000 pounds of combustible per
hour with 2 inches of water pressure in the ash pits.

The smoke flue and economizer construction throughout the building is of uniform design, or, in other
words, the smoke flue and economizer system for one chimney is identical with that for every other chimney.
In each case, the system is symmetrically arranged about its respective chimney, as can be seen by reference
to the plans.

The twelve boilers for each chimney are each provided with two round smoke uptakes, which carry the
products of combustion upward to the main smoke flue system on the economizer floor. A main smoke
flue is provided for each group of three boilers, and each pair of main smoke flues join together on the
center line of the chimney, where in each case one common flue carries the gases into the side of the
chimney. The two common flues last mentioned enter at opposite sides ot the chimney. The main flues
are arranged and fitted with dampers, so that the gases can pass directly to the chimney, or else they can be
diverted through the economizers and thence reach the chimney.

The uptakes from each boiler are constructed of 3 s -inch plate and each is lined with radial hollow brick
4 inches thick. Each is provided with a damper which operates on a shaft turning in roller bearings. The
uptakes rest on iron beams at the bottom, and at the top, where they join the main flue, means are provided

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Online LibraryInterborough Rapid Transit CompanyInterborough Rapid Transit: the New York subway; its construction and equipment → online text (page 6 of 13)