CLASSIFICATION OF BUILDINGS.

384. The entire establishment of buildings for operating a railroad, consists of the

And appertaining to these, scales for the weighing of cars and freight; turntables, transfer tables, switch and gate houses.

LOCATION OF BUILDINGS.

385. The location of the several buildings mentioned above will depend upon the situation of the terminus, the character of the traffic, and the number of trains arriving and departing.

TERMINAL PASSENGER HOUSE.

386. The passenger house should be at the most convenient point of access to the persons using it. The freight buildings should be at the most convenient point for receiving, shipping, and distributing merchandise.

The engine and car houses, with the shops for repair, may be placed where the land is cheap, and so distant from dwelling-houses as not to cause inconvenience to the inmates thereof by smoke and noise. The wood sheds, tanks, turntables, etc., etc., are generally at the engine houses; weigh scales, etc., at the freight buildings.

387. A railroad which connects the interior with a seaport, would probably bring two classes of freight; one for export and one for home consumption. The first should be carried at once to the wharves and loaded into the ships with one transshipment; while the second should be delivered as near as possible to the centre of home trade.

The departments of arrival and departure should be kept quite distinct, when the amount of business transacted is considerable; otherwise operating will become complicated. The arrival part of a large passenger house requires a great number of doors, that exit may be easy to the large number of passengers that arrive at once. The departure rooms require few doors, as departing passengers come singly or in small bodies. Thus, in large cities the front of a long rectangle is given to departure, while a long side, communicating with an outside platform, forms the arriving room.

One thing in particular ought to be looked to by American railroad companies,—the arrangement of public vehicles that shall secure travellers from the impositions and extortions of hack-drivers. No person whatever should have access to any building except passengers and the railroad officials. The places of the several carriages, and the rates of pay for the same, should be fixed by the company; the fare being paid by checks bought by the traveller from a company agent at the station.

388. The terminal freight house should contain all of the apparatus necessary for receiving and embarking freight. When the central part of the building is occupied by tracks, and the sides by platforms, the landing platform should incline gently from the car to the door; and that for loading, from the door to the car. This arrangement facilitates the handling of freight. The interior of the building may be divided into departments, either according to the destination or the class of the freight.

ENGINE HOUSE AND APPURTENANCES.

389. A terminal engine house, with a table in the centre, to contain

The diameter of the table being forty-five feet, and the engine occupying, when off from the table, fifty feet. Again, thirty-two engines would require a diameter of

The engines within the house may be supplied with water from small tanks between each alternate pair of pits, (each tank holding five thousand gallons,) or the entire building may be furnished from a cast-iron pipe running around the whole, and being in connection with a large tank. In such pipe there should be a gate over the centre of each pit, and near its upper end. It may be convenient to connect all to a series of small tanks, by a pipe, that the water level may be kept nearly constant.

Repair shops for engines and for cars, may be plain, rectangular buildings, so arranged as to accommodate the necessary machinery.

Turntables consist of simply a circular framework of wood or iron, placed at the centre upon a solid iron pintle which bears the whole weight, and guided at the circumference by a series of fifteen, eighteen, or twenty wheels fourteen or fifteen inches in diameter. The wheels are placed in an independent spider frame, and run upon a curved rail placed on the bottom masonry, and the table runs upon the top of the wheels, so that the motion of the circumference of the table is double that of the wheels.

The frame consists, first, of a pair of timbers ten or twelve inches wide and fifteen or sixteen inches deep, upon which the rails are placed, strongly trussed so as to throw the load upon the centre. At right angles to these are placed, at a distance of eight or ten feet, timbers 5 × 10, also trussed, which serve to connect the load more completely with the wheels. The whole is stiffened by diagonal bracing, and is strongly floored. The table is turned by a pinion upon itself, working into a rack fastened to the foundation or to the side masonry. The trusses, as also the centre bearing, should be capable of adjustment vertically.

The cost of the table, exclusive of masonry, is from $1,200 to $1,800.

Weigh scales are made similar to, but stronger than, the ordinary hay-scales, being rigid and strong enough to bear the weight of a locomotive. Every car (freight) placed upon the road should have the number and the exact weight painted upon it in some conspicuous place, so that the contained load may, at any time, be found by placing the car upon the scale.

At way stations the freight and passenger houses, wood and water station, may all be combined; the plan and size depending upon the location and importance of the station. The relative position of the tank, wood shed, and passenger house should be such that when the tender is at the proper place for receiving its supplies the centre of a passenger train of ordinary length shall be at the passenger door.

OF THE WATER SUPPLY.

390. The number of engines leaving the terminus of a road determines the amount of water necessary at the principal stations; and the character of the road and of the traffic fixes the location and size of the way water stations. The amount of traffic being pretty equally distributed over the length of the road, the tanks should be placed at equal equated distances; thus the engines will need to water at closer points upon steep grades than upon level roads. Generally, however, the water is taken where it can be got, the location of streams and springs fixing the place. Steam, hydraulic, wind, human, or animal power may be employed to raise the water to the tank. Oftentimes high springs will fill the tanks without the application of artificial power. As we find the liquid water in nature it is more or less impregnated with vegetable, gaseous, and saline matter, which often impairs its fitness for mechanical purposes. These admixtures are derived from the rocks and ground over or through which the water flows. The incrustations which form in boilers are caused by the precipitation of the impurities in consequence of the concentration of water in the boiler. They may be effectually removed, no matter what their nature, by boiling charcoal in the water. If the water, previous to filtration, can be heated, to expel all the air and carbonic acid gas, which is often the solvent of the foreign matter, the filtering process will be accelerated, and will be more effectual. Rain water is more pure than any other; practically, perfectly so. River water comes next to it. Spring water is generally adulterated with basic salts in various forms, most of which may be precipitated by gently heating and filtering through charcoal.

391. Fig. 157 shows a convenient form for a tank house, with pump and heater.

A shows half interior section of the tank.

B, half elevation of tank.

C, pump; C′, supply pipe; d, suction pipe and strainer.

E, heater.

e, the short, and h, the long pipe.

H, the discharge pipe.

G, discharge valve.

I, counter weight for discharge pipe.

K, wheel for weight rope.

L, scale showing amount of water in the tank.

The heater shown in the cut is made of a coil of two inch pipe of iron. The short pipe descends from within six inches of the bottom of the tank to within two or three feet of the floor; then bending four or five times around spirally, turns up through the centre of the coil, and runs three or four feet into the tank. A small grate is placed in the lower part of the coil, and the whole apparatus is cased in sheet iron. By such an arrangement of pipe, circulation is obtained, and the water in the tank is kept quite warm. The following rules and tables may be found convenient.

392. The velocity of water in any pipe necessary to discharge a given quantity, in a fixed time, is expressed by

Where C is the number of cubic feet per hour, and a the area of the pipe.

393. The head necessary to send water through a given length of pipe, of any diameter, is shown by the formula

The experimental values of C and C′ are as follows: Let V equal the velocity in feet per minute, and we have

Also, the values of C′ are

EXAMPLE OF USE OF PRECEDING RULES.

Required the head of water necessary to send 1,333 cubic feet of water, or 10,000 gallons per hour, through an eight inch pipe one thousand feet long.

The velocity by rule one will be

By rule two (the value of C for 60 being 8.62, and for 70 11.40, that for 64 is 10 nearly), we have

which multiplied by ten (the number of times that one hundred is contained in one thousand feet, the distance), gives the result, twelve inches or one foot, which is the required head; and if the entrance to the tank is twenty feet high, we have, as the necessary head, 20 + 1 = 21 feet.

394. The formula expressing the power of an engine to raise a given amount of water is

Where W is the weight of a column of water, and V the velocity in feet per minute; also 33,000 the expression of a horse-power. For example, how many horse-power must an engine possess to raise one thousand cubic feet of water per hour through a six inch pipe fifty feet high?

The velocity will be

or eighty-five feet per minute. The weight of a column of water fifty feet high and six inches in diameter is

Also,

395. Among the pumps now in use for raising water at railroad stations are Carpenter’s rotary, Worthington’s, McGowan’s, and that of Messrs. Perkins and Bishop, either of which answers every purpose.

The weight of a cubic foot of cast-iron being 450 lbs., and the price being five cents per lb.