The development of the heating, electric power and lighting, gas, and water systems of the University has been closely allied to the physical plant expansion and to the advancements in accepted practices in the field of the various utilities. From time to time the various systems have been extended, modernized, or rebuilt as conditions warranted, and every effort has been made to have them conform to the standard practices of the day.
In general, the development of the heating plant may be divided into three periods, that of heating the individual buildings by means of stoves, that of the development of small independent heating plants to service groups of buildings, and that covering the development of a central heating plant and distribution system.
The development of the lighting system may also be divided into stages: first, the period when oil lamps were the sole means of illumination; second, the era when the University had a gaslighting system; third, the period when the change was being made from gas lighting to direct-current electrical illumination; and fourth, the time of the transfer to alternating-current electrical illumination and a system, cross connected between the University and the local utility company, to provide for a maximum of service with the least possible interruption.
The water supply system has also developed through three distinct periods: first, the period of individual wells and pumps; second, that of a University owned and operated central supply system; and third, that of the abandonment of the individual system in favor of the central water distribution system of the city of Ann Arbor.
Heating. — The first University structures erected in 1840 and those added to the physical plant up to the year 1879 were heated by the then universal means of wood-burning stoves. In 1879 two heating plants were installed, and steam became the medium for heating the buildings. One of these heating units was erected just northeast of University Hall, and the other was housed in a lean-to addition built at the east end of the Chemical Laboratory, later known as the Pharmacology Building. The first of these two units provided for the heating of the Law Building, University Hall, the Library, the Museum, the Dental Building, and the Homeopathic Hospital. These structures formed a compact group of buildings in the west and north sections of the campus. The second unit provided for the heating of the Chemical Laboratory and the Medical Building in the eastern part of the campus.
With these first heating plants came the beginning of a central heating distribution system. The various buildings were connected to the heating plants by steam mains and return lines buried Page 1746underground and were insulated by log coverings, isolated from the hot pipes by cast-iron spreaders.
A third heating plant was constructed in 1883-84 to care for heating of buildings in the southeast section of the campus. This unit provided heat for the Engineering Building (one of the professor's houses of 1840 which had been enlarged and remodeled), the Engineering Shops, and the Physical Laboratory. Soon after the erection of this unit, the heating plant at the Chemical Laboratory was abandoned, and the Chemical Laboratory and the Medical Building were connected with this unit.
The Homeopathic Hospital was moved from the campus in 1891 to new quarters on Catherine Street. This was the beginning of a hospital group remote from the campus proper, and a heating plant was established to serve the first building and subsequent additions. The Hospital unit expanded rapidly and by 1897 the plant, which had become incorporated in the original structure, was abandoned for a larger, independent heating plant known as the Hospital Boiler House. This Boiler House and equipment were expanded at various times as new building loads were added.
By 1894 the number of buildings on the campus had so increased that it became necessary either to build additional plants or to abandon those then in service for one central plant and distribution system. The latter plan seemed best and the structure known as the campus Boiler House and an underground heating tunnel system were built. This unit, at the site of the heating plant constructed in 1883-84, necessitated a complete enlargement of the old unit, the construction of a heating tunnel system, and the erection of a new 125-foot brick chimney.
The tunnel system consisted of approximately 2,400 feet of horseshoe-shaped brick tunnel, 6 feet 10 inches high and 5 feet 6 inches wide, in which heating mains were installed to service all the campus buildings. Two new 150-brake horsepower water-tube boilers were provided, and these were augmented by boilers removed from the heating plant at the University Hall and later by those from the plant at the Chemical Laboratory.
This, the first central heating plant, was destined to serve the University for a period of twenty years. Many changes and additions to equipment had to be made in an effort to keep the plant abreast of the demands of the rapidly expanding physical plant. Auxiliary steel stacks were built at one time to serve those boilers remote from the chimney and to increase their output. Many other expediencies, such as the installation of heat control on radiators and the weather-stripping of windows, were introduced throughout the University buildings in an effort to keep them properly heated.
By 1911 it had become evident that drastic changes were required in the heating system. Smith, Hinchman and Grylls, a Detroit firm of architects and engineers, was commissioned to study the problem and to prepare plans for an adequate central heating plant. As a result of these studies, construction of the present Washington Street Heating Plant and its system of distribution tunnels began in 1912. The project was completed in 1914, and the new unit served all University buildings, with the exception of the Hospitals, until 1924.
The site selected for the plant was in the valley, popularly known as the "Cat Hole," leading from the northeast part of the campus to the Huron River. This location, between Huron and Washington streets and also between the campus and the hospitals, was of such elevation that heating tunnels servicing the two Page 1747areas could be set at grades to permit the return of condensate to the plant by gravity flow. This location also permitted the installation of a spur railroad with an electrically driven locomotive, which provided an economical means of hauling coal from the Michigan Central Railroad to the storage pile adjacent to the heating plant.
The heating plant was a steel framed, reinforced concrete and brick structure containing 1,202,000 cubic feet of space and providing more room than was actually necessary, in order to take care of future expansion. The original installation consisted of eight 400-brake horsepower vertical-tube boilers fired by stokers and equipped with modern safety and operating devices. The operating room of the plant contained an air compressor, boiler feed water heaters, direct-current generators, and a 500-kilowatt, Corliss-driven, alternating-current generator to which, within a short period of time, was added domestic water-heating and softening equipment, so that hot softened water could be supplied to the boilers and to all University buildings.
An electrical and heating substation was erected over the original brick heating tunnel on the campus proper. This substation was connected with the Washington Street Heating Plant by a reinforced concrete tunnel 8 feet wide, 10 feet high, and 900 feet long. It carried steam, hot water, and return mains together with concrete-enclosed vitreous ducts to house electrical distribution cables.
The Washington Street Heating Plant, with subsequent improvements and additions of equipment, served the University until 1924. During this ten-year period two 500-brake horsepower, vertical-tube boilers were added, and the electrical generating equipment was expanded by the addition of two steam turbine generators, one of 600 kilowatts and the other of 1,200 kilowatts.
The early 1920's saw a rapid expansion in the University's physical plant. During this period, approximately 25,000,000 cubic feet of building space were added, and this made it necessary to increase the heating plant facilities. In 1924 an addition was constructed extending the building 136 feet and adding 598,000 cubic feet of space. A new 250-foot radial brick chimney was erected, and the coal storage site adjacent to the plant was enlarged. This improvement consisted of the construction of a concrete enclosed and lined basin capable of holding 40,000 tons of coal. Two 1,000-brake horsepower, horizontal-tube boilers and increased equipment were provided for water softening and heating.
Much concrete heating tunnel was added to the distribution system at this time. Aside from connecting links to the sites of the new buildings, 1,920 feet of heating tunnel, extending from the campus Substation along East University Avenue to South University Avenue and west to Alumni Memorial Hall, and 2,000 feet of similar tunnel, between the heating plant and University Hospital, were constructed. The completion of this expansion program saw all major University buildings, including the University Hospital, connected with the central heating plant.
From 1923 to 1935, as the number of University buildings increased, the heating plant, as remodeled in 1923-24, was expanded by the installation of additional boilers, a 1,022-brake horsepower, Sterling-type boiler in 1929, and a similar unit in 1930-31. The original eight 400-horsepower units were discarded.
The PWA-University building program of 1939, which added 8,443,000 cubic feet of building space to the physical Page 1748plant, required further heating facilities. A new 1,505-brake horsepower, three-drum, Sterling-type boiler was purchased at this time and a general modernization took place. The operating pressures of the boilers were changed from 150 pounds to 200 pounds, and a 1,100 cubic foot per minute, electrically driven air compressor and a 4,000-kilowatt steam turbine electrical generator were acquired. The change in operating pressure made the two 500-horsepower boilers installed in 1919 obsolete, and they were removed from the line.
The heating plant in 1943 housed two 1,000-, two 1,022-, and one 1,505-brake horsepower boilers or a total of 5,549 rated boiler horsepower. These boilers are capable of being operated at rates varying from 150 to 300 per cent of their rated capacity, thus making a maximum total of 13,625-brake horsepower available for the steam loads of the University. This equipment not only heats 81,500,000 cubic feet of building space, but provides power for electrical generation during the heating seasons, heats all domestic hot water, and provides for laboratory and kitchen steam loads as required in the various buildings. In 1948 a 300,000 pound-per-hour steam generating unit was installed.
The central Heating Plant was connected in 1954 with 115 buildings by means of approximately four and three-fourths miles of tunnels and more than three-fourths of a mile of secondary heating lines to smaller structures. In 1953-54 the Heating Plant burned 107,337,508 pounds of coal and generated 1,158,193,130 pounds of steam.
Electric power and lighting. — The University buildings, between the years 1840 to 1867, were illuminated by individual kerosene lamps. A local artificial gas company was established in 1867, and at that time the University buildings were piped for gas illumination. This method served until 1897 when the first electrical generating units were installed in the campus Boiler House. Two direct-current, 75-kilowatt, 220-volt generators, driven by Ridgeway engines, together with distribution lines, were provided. Buildings were also wired at this time. This service was expanded in 1901 by the addition of a 300-kilowatt, engine-driven generator of similar design.
Developments in electrical power and lighting during the early years of the century were so rapid that, like the heating system, the facilities were soon overtaxed. In planning for the Washington Street Heating Plant, ample provisions were made to alleviate this condition. The plant, as equipped, contained a 500-kilowatt, alternating-current, Corliss-driven generator with foundations complete for two additional units. This unit operated at 2,300 volts and served the campus buildings through primary cables installed in a duct system in the tunnel leading from the heating plant to the campus Substation. From this point, power was distributed to the various buildings. In addition to the new alternating-current generator, two 150-kilowatt, 250-volt, direct-current motor generator sets were installed to furnish direct-current service to various campus buildings, laboratories, and equipment.
In 1917 a 300-kilowatt turbogenerator was installed to provide additional electrical energy. This unit was replaced shortly thereafter by a 600-kilowatt unit. The building program of the early 1920's called for additional electrical loads, and in 1924 a 1,250-kilowatt turbogenerator was bought.
The design of the turbogenerators was such that they were operated under a discharge pressure, the steam going directly into the heating mains. In 1925 arrangements were made with the Detroit Page 1749Edison Company which resulted in the construction of a switch house and transformer station interconnecting the University's generating capacity with that of the Detroit Edison Company. Since then electrical energy has been developed in proportion to the demands of the heating loads — the University delivering electrical energy to the Edison Company during the heating season and taking energy from the company when the heating load is reduced to a point below the electrical demands.
The 500-kilowatt, Corliss-driven generator, installed in 1914, was replaced in 1930 by a 2,500 kilowatt turbogenerator, the change making possible not only a greater generating capacity but also an increase in exhaust steam for heating purposes.
In 1939 the University's physical plant was extended, and the generating capacity of the heating plant was increased to compensate for this growth. A 4,000-kilowatt turbogenerator was installed. With this unit the four turbogenerators had a total generating capacity of 8,350 kilowatts.
The electrical distribution system originally installed in the heating tunnels was changed because of the effect of excessive heat on the cable insulation and the carrying capacity of the copper. The present distribution system is a series of concrete and fiber underground raceways, carrying primary distribution cables from the Heating Plant to various University buildings where they terminate in underground transformer vaults from which secondary service is supplied to the buildings.
In 1953-54 the plant generated 25,473,226 kilowatts of electricity, purchased 14,965,400 kilowatts, and used 36,813,846 kilowatts.
Water. — During the early history of the University, the problem of a water supply was critical. The location of the campus on one of the higher sections of the city, together with the pervious nature of the underlying earth strata, made it all but impossible to obtain water by means of wells. When steam became the means of heating, a source of water became more urgent. Several means to obtain it were evolved. Large cisterns were constructed at various points on the campus into which rain water from neighboring roofs was conducted. Water for boiler purposes was then pumped from the cisterns.
Another early method of providing water consisted of piping spring water from natural springs near the site of the present Stadium to a receiving well near the intersection of Hill and South State streets. From this point it was pumped to the campus. This supply was meager owing to the distance that the water had to be conveyed through the small wooden pipes then used and the very small differential of elevation between the source and the outlet.
In 1885 the city of Ann Arbor gave a private company a franchise covering a water works system. The University has since obtained its supply from this utility. The city of Ann Arbor purchased the system in 1914, and it has been operated by the municipality since that time.
Water service to the various University buildings has been taken from the nearest adequate supply mains and is individually metered at the buildings. The only exception to individual building or building group service is the supply of hot water. Hot water for all University buildings is furnished through the Washington Street Heating Plant and distributed in University-owned mains in the heating tunnels.
The principal source of water for the municipal system is from wells which produce relatively hard water. Provisions were made at the heating plant to soften the raw water for use in the Page 1750boilers and in the domestic hot water system. When the municipal system built a softening and filtering plant in 1938, the need for softening all hot water at the heating plant was eliminated. Water direct from the city's mains is now heated for domestic supply, and only that used for boilers is softened to a further degree.
Water for fire protection for University buildings was provided by two services — one by hydrants connected to the city's distribution mains and the other by a University-owned high-pressure fire system which was installed in 1914. This latter system was connected at various points with the city's distribution system by check valves. Owing to cross-connection features this arrangement was discontinued. The University's high pressure mains are now leased to the city for use as distribution mains, and the high pressure pumping equipment has been removed.