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Electrical Review, January 28, 1911
As an indication of the importance of electricity as a potent factor in the economical and efficient operation of a giant merchandising establishment, the plant of Sears, Roebuck & Company, Chicago, Ill., is unique. This huge plant, which covers an area of forty acres, is equipped with every modern convenience known in present day engineer ing practice. For the proper heating, lighting and ventilating of the various buildings, for the prompt and accurate dispatch of the volume of written orders, letters, etc., for transferring mer chandise from different departments to the packing and shipping rooms, for operating the machines of a model printing plant, and for innumerable special purposes, electrical energy has been exclusively employed.
Sears Power Plant Building.
Although the company has been located in its present quarters for a number of years there have recently been made a number of important additions and changes both in buildings and power-plant equipment so that a description of the electrical and mechanical installation at this time is apropos.
The plant of Sears, Roebuck & Company is located on the west side of the city on a forty-acre tract of land, bounded by Central Park Avenue on the west, Kedzie Avenue on the east, Fillmore Street on the south and Har vard Street on the north. The buildings comprised in this tract are six in number, each designed for a special purpose. Starting at the extreme west corner is the merchandise building, with the new warehouse adjoining it on the south, the next building east is the administration building and the printing building is located at the southeast corner of the tract.
The power plant is located adjacent to the south side of the administration building and on the main line of the Chicago Great Western Railroad.
① Merchandise Building, ② Tower, ③ West Wings of Merchandise Building, ④ Administration Building, ⑤ Advertising & Printing Building, ⑥ Grocery Annex, ⑦ Paint Factory, ⑧ Wall Paper Mill, ⑨ Factory No. 1, ⑩ Power Plant.
The enormous amount of power, heat and light required in this group of buildings made it necessary to construct an isolated power plant, which has subsequently come to be regarded as one of the largest and most complete plants of its character in existence. An idea of the requirements im posed on this plant may be gained from the report of the chief electrician, which states that the total current consumption of the entire establishment for the past twelve months has been approximately 4,685,400 kilowatt-hours, while the current consumed in the printing plant alone, for a period of six months, was 194,430 kilowatt-hours.
As already stated the power plant occupies a position adjacent to the ad ministration building and approximately in the center of the tract of land occupied by the company. The build ing, covering an area of 30,000 square feet of space, is absolutely fireproof, constructed of steel, concrete and brick, and was especially designed to receive the special apparatus and machinery required. All of the generating apparatus, boilers, engines and part of the pump equipment are located on the first floor, while the connecting pipes, ash handling apparatus, pumps, etc., are located in the basement.
At the power plant of Sears, Roebuck & Company extensive provision has been made for the automatic handling of coal. A spur track of the Chicago Great Western Railroad is run adjacent to the south wall of the plant. This track is equipped with an automatic scale and after being weighed the coal is dumped into ehutes, which convey it to a crusher operated by a fifteen-horsepower motor. This crusher empties onto a belt conveyor, which carries the coal to the southwest corner of the plant, where it is taken by bucket conveyors to the coal bunkers over the boiler room. A five-horsepower motor operates the belt conveyor and a fifteen-horsepower motor is employed for operating the bucket conveyor.
The entire plant is divided by a longitudinal wall running east and west, extending from the basement to the roof. The northern section is the en gine room and consists only of a basement and main floor. The southern sec tion is the boiler room with basement and a floor above the boilers, equipped as coal bunkers. Coal is emptied from the bucket conveyors into a portable dumper, which distributes it to the bunkers over each boiler. Each of these bunkers has a storage capacity of 100 long tons.
The boiler equipment of this plant comprises twelve 500-horsepower watertube boilers located in a single row and divided into batteries of four each. The boilers, which are of the Aultman-Taylor manufacture, have a heating surface of 5,000 square feet each, and each is equipped with a superheater.
General View of Power Plant.
The furnaces are provided with traveling chain grate stokers, each having a grate surface of ninety square feet. Two Wachs 8 by 8 engines are em ployed for operating the stoker main shaft. Coal is admitted to the stokers through spouts connected to the coal bunkers. Two of the furnaces are equipped to burn refuse from the offices.
Ashes are dumped from each furnace onto a belt conveyor, which empties into a bucket conveyor. This latter conveyor carries the ashes to the southeast corner of the upper floor, where they are dumped into railroad cars through steel chutes. The coal and ash-handling machinery has a capacity of 100 tons per hour. An interesting feature of the boiler-room installation at this plant is the fact that only two men are required to operate it—one man having charge of six boilers with the corresponding auxiliary apparatus.
Located between the two batteries of boilers are the boiler-feed pumps. There are two of these pumps, each 10 by 16 by 8.5 by 18, of the compound duplex type, furnished by Fairbanks, Morse & Company. Each pump is controlled by a Fisher governor, The steam piping has been designed to take care of any emergency that may arise. Six-inch bends connect each boiler with the main header, which is sixteen inches in size. This main header is looped in the engine room so that either four boilers may supply any of the engines. The exhaust from the engines is conducted to a thirty-six-inch exhaust header, which is connected to two Austin oil separators. The exhaust steam is then passed into an expansion tank, and when necessary is mixed with live steam for the heating system. In summer when the heating system is not in operation the exhaust steam is passed to atmosphere.
One of the unique features of this power plant is its towering chimney, which furnishes the requisite draft for the boilers. This chimney is constructed of radial brick. It is 250 feet high, fourteen feet in diameter, and is supported on concrete caisson foun dations sixty feet in depth, the height from bed rock to crown being 310 feet. The weight of this smoke stack is 2,500 tons.
Located in the basement of the boiler-room section there is installed a twenty-ton Carbondale ice machine, which is used for manufacturing ice for the restaurants, drinking-water supply, etc. Adjacent to this machine there is a house-service pump, operated by a thirty-five-horsepower Bullock motor, which pumps the drinking wa ter from the main reservoir which furnishes the requisite draft for the boilers. This chimney is con structed of radial brick. It is 250 feet high, fourteen feet in diameter, and is supported on concrete caisson foun dations sixty feet in depth, the height
The engine room is extremely ornamental, finished throughout with whiteenameled brick with red English tile floor, and a spacious visitors’ gallery along the north wall. The entire power plant is designed and laid out to permit of the greatest economy in its mechanical operation.
The entire western section of the engine room is taken up with the pump installation. This equipment com prises two 16 by 22 by 20 Marsh vac uum pumps for the heating system; two 8 by 12 by 8 by 18 steam house pumps; one two-stage 10 by 18 by 11 by 12 air compressor, having a capacity of 300 cubic feet per minute, for vac uum cleaning purposes, conducting refuse to the engine room, etc.; one two-stage air compressor for the pneumatic-tube system; three compound duplex elevator pumps, one high-pressure fire pump and several smaller pumps for miscellaneous service. A view of the pump installation is shown in one of the accompanying illustrations.
General View of Pump Installation.
The generating units and switch board occupy the remainder of the engine room. Situated in a single row in the center of the room are the four main units. Beginning at the east end the first three are 24 by 50 by 48 crosscompound Allis-Chalmers Corliss en gines direct connected to three 750kilowatt, 220-volt direct-current Bul lock generators. The fourth unit comprises a 20 by 40 by 42 cross-compound Allis-Chalmers Corliss, condensing engine direct connected to a 500-kilowatt, 220-volt Bullock generator. The three large units operate at a speed of eighty-five revolutions, while the small unit operates at a speed of ninety-five revolutions per minute. Each engine is equipped with a Richardson auto matic oil pump.
For supplying current to the extensive fire-alarm system, buzzers, alarm-bells and graphophones there are provided in the engine room two low-volt age generators, these circuits being car ried independently throughout the entire plant. The low-voltage units are located adjacent to the pumps, on spe cial foundations, removed from the main units. They comprise a 12 by 12 Ames simplex engine driving a fifty kilowatt, twenty-volt generator and a 14 by 14 Ames simplex engine driving a 100-kilowatt, twenty-volt generator.
Main Switchboard.
The main switchboard is a model of its kind. It is located adjacent to the north wall of the plant and is of the standard angle-iron frame construc tion. There are twenty panels of blue Tennessee marble about one inch thick. Each panel is equipped with the latest controlling, measuring and regulating apparatus, including integrating watt meters, recording wattmeters, station voltmeters, etc.
All leads from the generators are run in iron conduit to the basement, where they are grouped and conducted to the switchboard. The board is equipped with two sets of main bus bars, which are interchangeable, in case of accident. All power circuits are controlled from panels on the left of the board and all of the lighting cir cuits are controlled from panels on the right side.
The engine room is equipped with a gravity oiling system, all oil being pumped to a tank in the southeast end of the boiler room over the coal-conveying machinery. A twenty-five-ton traveling electric crane spans the engine room.
A comprehensive system of tunnels connects the engine room with all of the buildings. In these tunnels all elec trical wiring, steam pipes, water pipes and refuse conveyors are run.
The heating and ventilating appara tus installed in the various buildings operating from the power plant is very elaborate and complete. The blast system employed in heating the build ing is so equipped that in winter time a uniform temperature is maintained, while in the summer time ventilation is furnished every part of the buildings by means of a supply of fresh filtered air. In conjunction with the blast system of heating there are used a number of steam radiators, placed around the more exposed portions of the rooms.
To describe the ventilating system it is necessary to state that owing to the size of the two main buildings the administration and merchandise they are divided into sections with fireproof dividing walls. At each of these dividing walls there is installed in a special air chamber a motor-driven fan, which supplies either cool air in summer or hot air in winter to the section in which it is installed. There are thirty-three of these fans, each operated by a twenty-horsepower motor. Fresh air intakes are located on the roofs over each section. Ducts convey the air to the ventilating chamber, where it is washed before being distributed through the buildings. In severe cold weather these intakes are closed and only heated air distributed.
Pneumatic Tube System.
Probably the most valuable time saver employed in the plant of Sears, Roebuck & Company, to facilitate the transaction of business, is the very elaborate system of pneumatic tubes used for sending written communications, orders, etc., between departments throughout the several build ings. More than fifteen miles of tubing are used in this system, which is said to be the largest of its kind in existence. Letters and orders are all received in the Administration building, where the central station is lo cated, and are from there dispatched to the proper merchandise or clerical department. The carriers are of the The motor installation in this estab lishment comprise a total of 480, ranging in size from one-half horsepower to 150 horsepower. In the printing building alone 125 motors are em ployed. The printing building is a modern fireproof structure, 250 feet long, 90 feet wide and four stories high, and is devoted exclusively to printing catalogues, stationery, etc., required by the company.
The main press room is on the first floor and contains twenty motor-driven printing presses. Ten-horsepower motors are used for driving these presses, which are also equipped with the cen tral control system. In all other operations automatic machines are em ployed wherever possible and in every instance an electric motor furnishes the motive power. Among the more important machines may be mentioned folding machines, trimming machines, assembling machines, job presses, etc.
There is also provided a complete ?electrotyping plant comprising motordriven, trimmers, blacking machines, routers, saws, and motor-driven plating dynamos. As in other departments, the printing building is equipped with an elaborate system of conveyors for transferring the product from one department to another.
An interesting feature of the installation in the printing building is the equipment for handling the scrap paper. Convenient to the trimming machines there is located a huge spout into which all trimming from the catalogue are dumped. By means of compressed air this material is conveyed to a department in which the paper is bailed and returned to the paper mills.
As previously mentioned two of the boilers in the power plant are equipped to burn refuse. In this connection there is installed in the basement of the merchandise building two grinding machines each operated by a 100-horsepower Bullock motor. In every department of the building there is provided a chute into which the refuse such as pa per, boxes, catalogues, etc., is dumped. These chutes empty into a main bunker, equipped with an automatic door, and as needed this refuse is fed into the two grinding machines. This material is then conducted through ducts to the storage bin over the two boilers in the boiler room and fed to the stokers.
View of Typical Lighting Installation in a Department.
The lighting installation in the vari ous buildings is one of the most complete and approved installations in an establishment of this character. The total equipment of lamps comprises eighty inclosed arc lamps, 3,000 tungsten-fila ment lamps, 6,200 Nernst lamps, 32,000 carbon-filament lamps and 200 Cooper Hewitt lamps.
In the majority of large rooms where many are employed single-glower Nernst lamps arc almost exclusively em ployed. These are generally suspended about five feet from the ceiling by or namental chains and are arranged in single rows spaced about ten feet apart. In other departments where conditions warrant it carbon or tungsten filament lamps are used. In the printing building and shipping depart ment Cooper Hewitt lamps are employed. The eighty arc lamps are used only for exterior lighting and in the train shed.
In one department, Mr. Church, chief electrician of the plant, has made an in stallation of indirect lighting for experimental purposes. Sixty-watt tungsten-filament lamps are employed, installed in ornamental bowl reflectors. This installation has proved so satisfactory that extensions of this system of lighting are being contemplated.
A feature of interest in the plant of Sears, Roebuck & Co. is the fire-protection system. The plant is equipped with a supervisory signal system which indirates at any time of night or day the condition of all the fire-protection ap paratus. A complete electric fire alarm system is installed which registers in the engine room and fire alarm station only. At night, however, by turning in an alarm, every station would record the alarm.
The entire plant is under the supervision of A. P. Wright, chief engineer.
Exterior View of the Merchandise Building at Night.
Homan Square
Completed in 1905 as one of four main buildings of the George C. Nimmons designed Sears, Roebuck and Co. complex (listed on the National Register of Historic Places in 1978), the Power House powered the massive 55-acre Sears complex until the company’s 1973 relocation to the Sears Tower in downtown Chicago. Minimal operations continued until 2004, when the Power House was fully decommissioned; vacant and deteriorating, becoming a classic “white elephant” building with limited reuse.
What began as a simple quest to determine the best use for an empty building, turned into a grand plan for reclaiming a chunk of Chicago history by offering brighter futures to kids in a tragically underserved neighborhood.
The Charles H. Shaw Technology and Learning Center is now home to DRW Noble Charter School. A $40 million restoration and historic preservation effort resulted in a LEED Platinum certified historic structure that now operates as a modern public charter high school.