"The Power Plants of the Pan-American Exposition"1
The Pan-American Exposition at Buffalo is served with power from three separate plants, one devoted chiefly to exterior decorative illumination, the second to power for service, partially intended as an exhibit, and the third largely to pumping machinery for the operation of most of the various fountains. The first plant is entirely electrical, utilizing high-tension current from Niagara, and is an exhibit plant, consisting of General Electric apparatus, next to the regular floor space given to that company in the Electricity Building. A chief point of interest lies in the use of 25-cycle current for lighting in lamps of 8 candlepower. The second plant marks an interesting combination of a purely initial utility plant augmented by a large number of show steam and electric machines which have proven of considerable value, as the demands for power greatly exceed the first expectations. In this are supplied both direct and alternating current. Steam is generated in a large battery of vertical boilers burning natural gas. The whole plant is housed in one building located at the northwest corner of the grounds. The third plant contains both steam and gas engines for driving pumps and a number of steam-electric units. It is altogether an exhibition plant, occupying a central court several feet below the general floor-level in the Machinery and Transportation Building. Steam is carried to it from a boiler plant across the canal from the building, 200 feet distant. Natural gas is used in both boilers and gas engines.
The Niagara current, from the Niagara Falls Power Company, enters the grounds at one side near the service plant) in six conductors on a single-pole line. Through the grounds to the Electricity Building it is carried underground in lead sheathed conductors boxed in wood, but its admission into this circuit is controlled by means of a water rheostat consisting of three tanks corresponding to the three conductors of the three-phase current. Large blades lowered into these tanks by motors close the circuit gradually, and the incandescent lights throughout the grounds are brought slowly to full illumination, the period lasting about 80 seconds and affording a spectacle which is waited for every evening by the sight-seeing crowds. The rheostats are enclosed in a wooden house built on posts above the ground and operated at that point. The motor, however, may be controlled from the service plant and the Electricity Building.
At the Electricity Building, the high-tension current, which is at about 11,000 volts, is stepped down to 1800 volts, and for that purpose there are 19 transformers of an aggregate of 4,750 kilowatts, together with oil-break switches and a blue marble switchboard of fourteen panels. The 11,000-volt feeders pass first through an oil-break switch enclosed in a brick chamber extending above the floor and operated by a small motor controlled from the switchboard. They then rise through the floor and are carried overhead across six compartments on triple petticoat insulators on light angle-iron frames. Opposite each compartment the feeders are tapped and the branches are connected to auxiliary oil-break switches in each compartment. These compartments are formed of brick partitions 4 inches thick, cement bottom, 2-inch stone tops and sheet-steel doors, lined with asbestos. Each switch is operated from the switchboard, two on each of three panels. Leaving the switches they pass through the floor into a large cellar room about 7½ feet high, with brick walls, asbestos board ceiling and wood floor. In this all the connections are made to the transformers and the forced blast of air for the transformers, which are of the air-cooled type, is discharged into it. The branch high-tension leads from the switches go east to a set of three transformers which are connected in delta, the nineteenth transformer being in reserve. The secondaries are connected similarly and the 1,800-volt wires are run to points below the switchboard,. where they rise to oil-break switches placed immediately behind the board.
There are three switchboard panels devoted to the six sets of 1,800-volt wires, and each line is protected with a circuit breaker. Three bus bars extend along behind the board at the top, and these are supplied from the secondary feeders from the oil-break switches, and in turn supply outgoing feeders through similar hand-operated oil-break switches with circuit breakers on the face of the board, these also grouped in pairs, twelve feeders in on six panels. The six 11,000-volt switches are of about 32 amperes capacity, the six 1,800-volt switches on the line from the transformers, of amperes, and on each outgoing feeder 136 amperes. The first panel of the board contains a polyphase meter and a time-limit relay, besides a voltmeter on swinging bracket. The transformers are air cooled, as stated, and there are two single-inlet Buffalo Forge Company centrifugal blowers, each electrically driven by direct-connected 110-volt motor running at about 375 revolutions per minute. The transformers require one-half ounce air pressure.
The power plant at the northwest corner of the grounds, the combination service and exhibit plant, occupies a large frame and plainly temporary building, 170 x 200 feet in plan. It is of the type in which there is a longitudinal dividing wall separating the boiler and engine rooms, the boiler room occupying probably one-quarter of the space, and the engine room practically all the rest; the switchboard is on the opposite side of the room from the boilers. The boilers are of the vertical type, 19 in all, placed in a single row, and all connected for burning natural gas, the gas burners entering at the front and the main supply gas header extending across in front of them on the floor. On the back side of the station building are the steam railroad tracks and a siding is provided for coal delivery, with coal storage openfrom the firing space. Considerable coal is already on hand, so that in the event of temporary failure of the gas, coal may be relied on to prevent a break in continuous operation. At the middle point of the coal-storage space is a small extension or shed, in which is located the boiler-feed apparatus. This consists of Snow steam pumps, one 10 x 6 x 10, a compound one 8 x 12 x 7 x 12, and another compound with double water ends 6½ x 10 x 6 x 10, and five injectors, the latter installed side by side in the same room, in cross-connection on the feed line.
The steam from each boiler, which is maintained at a pressure of about 110 pounds, is taken from the top, and each steam pipe enters into the top of a steam header supported overhead and pitching toward one end for drainage. It is supported by wrought-iron pipes, two pipes at each point, these being bedded by flange ends on foundation piers for the purpose and the two rising inclined toward each other, connecting at the top by elbows into the ends of a short, straight piece of pipe on which the steam header rests. The branches to the various engines rise in the usual manner from the top of the main, pierce the division wall and drop to the engine cylinders. In general each has a right-angle elbow at the base of the drop, and into this is inserted a drip pipe for relieving such water as might otherwise get into the engine cylinders. The exhaust is carried under the floor to two Otto feed heaters, filters and oil separators.
The boilers are also provided with an induced draft apparatus put in by the Buffalo Forge Company. This is a duplex installation, located on a platform in the engine room under which an oil room has been partitioned off. Each fan is direct connected to a Buffalo Forge Company horizontal steam engine.
There are at present 12 steam engines in the building, some, as stated, comprising the original service equipment and the others, new machines installed as useful exhibits. They all drive electric machines by belt, so that steam engine and generator run at suited speeds and there were not the delays sometimes experienced in connecting two such machines directly, a condition which floor space did not make of first demand. There are 16 65-light Brush arc-light dynamos, arranged in four sets of 3 each, driven from simple engines made by the John T. Noye Manufacturing Company, by separate belts on the same driving flywheel. The remaining four are belt-driven in pairs from Armington & Sims engines of the center crank type with two flywheels, each carrying a driving belt. The arc machines are 2,900-volt 9.6-ampere dynamos.
Direct current is furnished for other purposes at 550 volts by four 200-kilowatt Westinghouse generators driven by compound Armington & Sims engines and at 125 volts by two 45-kilo-watt Westinghouse generators driven by a simple Armington & Sims engine. Two-phase alternating current is supplied at 60 cycles in a 2,400-volt 300-kilowatt Stanley generator, driven by an engine made by the Phoenix Iron Works and in a 2,200-volt 180-kilowatt Westinghouse generator belted to a Buffalo Forge Company engine of the tandem-compound type. A Stanley frequency charger of 80-kilowatts capacity to charge from 25 to 60 cycles per second, at the time of writing, had yet to be put in place.
In one of the front corners of the building, that is, distant from the boiler room, are located the fire pumps in connection with the fire extinguishing system about the grounds. This is a small room of brick with concrete arched ceiling, to have as high a degree of fire-resisting qualities as practicable. It contains three Snow duplex fire pumps of 16 x 9 x 12-inch cylinder dimensions and of 750 gallons per minute capacity at a speed of 70 revolutions per minute. The room is fed with steam in a pipe carried across the building under the roof trusses. It is supported in a manner similar to that in which the main header behind the boilers is carried. The supports in this case are 20 or 25 feet high with the two incline stanchions about 18 inches apart at the top and 3 feet at the bottom. The corresponding opposite corner of the building is framed in for use as a store room. There is a small refrigerating set in the station used in connection with the principal catering establishment on the grounds. This consists of a Buffalo Refrigerating Machine Company compressor and two Hall pumps.
The switchboard is made up of a number of sections, each section In general being furnished by the maker of the electrical machinery which it controls. There are four white marble panels for direct current with double-pole switches of single-throw and circuit breakers, ammeters and rheostats. Next to these are two blue marble panels for the Stanley machines, then three panels with Westinghouse Instruments, two for direct current with three-pole switches to include equalizer and the third for the Westinghouse two-phase alternator with arrangement for two feeders. Finally are three sets of feeder plugs for the arc lights. It will thus be seen that the switchboards simply serve to control the machines, the current then being distributed to switchboards or controlling devices at points of use; similar in a way to the decorative light distribution, in which the 1,800-volt circuits are carried about the grounds to transformers stepping down to 104 volts at which pressure the lamps are wired in parallel.
The plant in the center of the Machinery and Transportation building is, as stated, a number of feet below the general floor level, roofed off in the open court about 4 feet above the floor. At each end It will be accessible by a stairway and there will be a public gangway down the center. It is about 100 x 200 feet in main dimensions. Along one side are spaced 12 rotary pumps, all driven by belt-in one case by a rope drive-from prime movers which lie along the longitudinal axis. Between these and the other side of the room are a number of electric-generating units and condensing apparatus.
The pumps were all made by the P. H. & F. M. Roots Company, and eight of them are of a capacity of 2,500 gallons per minute, and four of 1,500 gallons capacity. Seven of the larger are driven from steam engines, while the eighth and the small ones are all run from gas engines. The larger pumps run at 180 revolutions per minute and the smaller at 260 revolutions per minute, maintaining 100 pounds pressure; all discharge Into a header which subdivides Into two mains, one for the main electric fountain arid the other for practically all the rest. The engines driving the pumps are primarily exhibition machines, and, of course, of different powers. In order from one end, they are an American Ball of its well-known compound type, a Sioux City tandem-compound made by the Murray Iron Works of Burlington, Ia., of a Corliss type with a 16-foot flywheel carrying a rope drive to the pump pulley, an Ames Iron Works, of the simple center-crank high-speed type, a Lane & Bodley, Cincinnati, Twentieth Century engine, of the simple type with a two-eccentric Corliss valve motion, a Harrisburg Standard tandem-compound four-valve engine, a Fitchburg Steam Engine Company's two-eccentric engine and a Watertown, N. Y., Engine Company's simple four-valve engine, these concluding the steam engines; and a large vertical three-cylinder gas engine made by Struthers, Wells & Co., driving the eighth of the large pumps, a vertical three-cylinder Nash gas engine made by the National Meter Company, a Bessemer horizontal two-cylinder two-cycle engine, cylinders side by side, made by the Bessemer, Pa., Gas Engine Company, a Walrath vertical three-cylinder throttling governor engine, made by the Marinette Iron Works Manufacturing Company, and a Buffalo tandem horizontal engine, the last four running the smaller pumps and all using natural gas.
The steam-electric units Include an American Ball dynamo directly driven by an American Ball engine, a 126-volt Onondaga dynamo direct-connected to a simple Straight Line engine, a Keystone generator belt driven from a Skinner automatic simple engine made by the Skinner Engine Company of Erie, and a Keystone dynamo in direct connection with a Ball engine made by the Ball Engine Company of Erie, Pa. Some of the steam engines are run condensing, and for that purpose a large Wheeler surface condenser is installed, the exhaust approaching it from opposite directions, the two exhaust mains rising from under the floor and connecting with a Cockrane oil separator in each case before entering the condenser. The condensation is returned through a large Cockrane feed-water heater and purifier which receives and condenses steam for the engines operated non-condensing. Two Snow feed pumps take care of the return of the water to the boilers.
The boiler plant for the steam machinery in the Machinery building is located in a separate building across the canal from it. It is about 60 feet square in plan, and contains four 500-horse-power Morrin Climax boilers built by the Clonbrock Steam Boiler Works of Brooklyn. They are arranged for burning natural gas, a gas main encircling each near the bottom and feeding 20 burners. A steam pressure of about 126 pounds is maintained and the steam is carried from the boiler house in an 18-inch main partly underground, covered with about 2 inches of hair and partly on a bridge crossing the canal to the end of the Machinery building. Two injectors are also available for feeding purposes cross-connected on the feed line from the Snow pumps.
The officials to whom credit is due for the general planning of the work described and the supervision of its many details are: Director-General, Hon. William I. Buchanan; Director of Works, Mr. Newcomb Carlton, M. E.; and Chief of the Mechanical and Electrical, Bureau, Mr. Henry Rustin. Mr. Luther Stieringer is consulting engineer on electric illumination; Mr. J. H. Murphy, general superintendent of building construction, and Mr. Harry Weatherwax, chief draftsman.
1. The article"The Power Plants of the Pan-American Exposition," reproduced here in full, appeared in The Engineering Record, vol. 43, no. 21 (May 25, 1901) pp. 500-501. No author was cited.