rock river generating station haer wi-119 935 west b r

PHOTOGRAPHS

WRITTEN HISTORICAL AND DESCRIPTIVE DATA

FIELD RECORDS

HAER WI-119HAER WI-119

ROCK RIVER GENERATING STATION935 West B R Townline RoadBeloitRock CountyWisconsin

HISTORIC AMERICAN ENGINEERING RECORDNational Park Service

U.S. Department of the Interior1849 C Street NW

Washington, DC 20240-0001

HISTORIC AMERICAN ENGINEERING RECORD

ROCK RIVER GENERATING STATION

HAER No. WI-119

Location: 935 W. BR Townline Road, Beloit, Rock County, Wisconsin

The Rock River Generating Station encompasses approximately 18 acres; the following two coordinates

represent the northernmost and southernmost points of the plant and associated structures.

42.582267°, -89.027448° (north corner of plant)

42.575032°, -89.030695° (southwest end of discharge canal)

These coordinates were obtained on June 6, 2016, by plotting their location on the 1:24,000 Beloit U.S.

Geological Survey (USGS) Topographic Quadrangle Map. The accuracy of the coordinates is +/- 12

meters. The coordinates’ datum is North American Datum 1983. The Rock River Generating Station

location has no restriction on its release to the public.

Present Owner: Alliant Energy

Present Use: Vacant

Significance: The Rock River Generating Station is significant for its role in the post-World War II (postwar)

expansion of Wisconsin’s electrical utility infrastructure and is one of at least 14 coal-fired plants constructed

statewide by private utilities during this period.1 The Rock River station represents the culmination of the

seven-year construction program initiated by the Wisconsin Power and Light Company (WP&L) in 1947 and

is the largest single facility built by the company under this program. WP&L supplied electricity to much of

south-central Wisconsin during this period, including 336 communities, several important manufacturing

centers, and over 30,000 farms. The Rock River plant played a crucial role in WP&L’s ability to meet the

demands imposed by modernized agriculture and the Korean-war-era defense industry.

Historian(s): Sebastian Renfield and Christina Slattery, Mead & Hunt, Inc. Fieldwork for the project was

conducted in the summer of 2015. Project documentation was accepted by HABS/HAER in 2016.

Project Information: This documentation was completed by Mead & Hunt, Inc. at the request of Alliant

Energy, in consultation with the Wisconsin State Historic Preservation Office. Alliant Energy demolished

the property in 2016. Under the requirements of Section 106 of the National Historic Preservation Act,

this documentation was prepared as mitigation for the demolition of the National Register of Historic

Places (National Register)-eligible property. Representatives of Alliant Energy furnished original

drawings, photographs, and interviews. Project photography was produced by Dietrich Floeter.

1 This figure is derived from 2003 data listing extant Wisconsin plants with construction dates between 1945 and

1960. The total includes expansions of pre-war facilities and does not include plants constructed by individual

manufacturers or institutions to supply their own power. Energy Information Administration, U.S. Department of

Energy, “Existing Electric Generating Units in the United States, 2003,” 2003,

http://www.eia.gov/electricity/capacity/xls/existing_gen_units_2003.xls. (accessed June 8, 2016).


HAER No. WI-119

Page 2

Part I. Historical Information

A. Physical History:

1. Date(s) of construction: 1952-1955. Construction began on Unit 1 in January 1952 and was

completed in 1954, along with the crib house and circulating water discharge system.2 Unit 1 was

placed into operation immediately and a temporary northwest end wall separated the two units

while Unit 2 was under construction. Unit 2 was completed and placed on line in November

1955.3

2. Architect/Engineer: Sargent & Lundy, LLC. The firm’s founder and senior partner, Frederick

Sargent, began his career as an electrical engineer in 1884 with Western Edison Light Company

in Chicago and continued to serve as a consultant to Edison throughout his life. Sargent

established a partnership with Ayres Lundy in 1891 and the firm of Sargent & Lundy went on to

design a number of important early electrical generating plants, including Chicago Edison

Company’s Harrison Street station in 1892.4 At the time of its construction, the Harrison Street

Station was the largest coal-fired plant in the United States and the first to employ condensing

engines that reduced coal consumption by half.5 The firm continued to innovate both in fossil-

fuel-based generating technology and later nuclear power, and designed the world’s first boiling

water reactor at the Argonne National Laboratory in the mid-1950s.6 By 1974 the company

advertised itself as the largest design firm in the United States.7 Sargent & Lundy continues to

design power-generating facilities and remains based in Chicago.

3. Builder/Contractor/Supplier:

Lakeside Bridge & Steel Co., Milwaukee, Wis.: structural steel fabricator/erector (Unit 1)

Worden-Allen Co., Milwaukee, Wis.: structural steel fabricator/erector (Unit 2)

Cunningham Brothers, Inc., general contractors

Allis-Chalmers, Milwaukee, Wis.: turbine-generator units

Babcock & Wilcox, New York, NY: cyclone furnaces

Rex Chain Belt Company, Milwaukee, Wis.: coal handling conveyors and equipment

Janesville Brick and Fuel Yards, Janesville, Wis.: Brick for walls and stack lining

Westphal & Co., Janesville, Wis.: electrical wiring

2 Wisconsin Power and Light Company, Annual Report, 1954 ([Madison, Wis.]: Wisconsin Power and Light

Company, 1955), 3, 10.


Company, 1956), 7.

4 “In Memoriam,” General Electric Review 22, no. 8 (August 1919): 631; “Power Development in Chicago,”

Electrical World 76, no. 13 (September 24, 1920): 620.

5 Sargent & Lundy, LLC, “Company History,” 2015, http://www.sargentlundy.com/about/company-history.html

(accessed June 9, 2016).

6 Sargent & Lundy, LLC, “Company History.”

7 “Advertisement,” Reading Eagle, June 2, 1974.

http://www.sargentlundy.com/about/company-history.html


HAER No. WI-119

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Western Architectural Iron Company, Chicago, Ill.: steel stairs and galleries

Midwest Piping Company, Inc., St. Louis, Missouri: Pipe fabrication and erection

R&I Equipment, Greensburg, Penn.: substation

Fairbanks, Morse & Co.: cool water pumping system

Ingersoll-Rand, New York, NY: boiler feed pumps, soot blower and instrument air compressors.8

4. Original plans and construction: Plans for the Rock River Generating Station were prepared

successively by Sargent & Lundy, LLC over a period of several years while the plant was under

construction. The earliest plans for the structural aspects of the facility are dated January 1952,

and additional plans were prepared through 1953. Artists’ renderings and photographs of the

newly completed facility (see Figures 1 through 3) show the plant looking much as it did at the

time it was retired. The view facing south shows the stepped massing of the crib house, turbine

block, and boiler block, and the meeting/locker room area protruding slightly beyond the wall

plane on the southwest elevation. Transformers flanked the crib house and the original

substation was located north of the plant in the same location as the current substation. Paired

smokestacks rose above the roofline of the boiler block, and the uppermost two stories of the

boiler block were lit by bands of metal windows, now obscured by the addition of the electrostatic

precipitators. The complex also included two small brick buildings with flat roofs that served as

the deep well house and blower house, both located west of the plant. Several small storage

sheds were erected in the paved yard on the west side of the main plant. All three buildings are

prefabricated metal buildings with low arch-truss roofs.

Historic photographs from the 1950s and 1970s (see Figures 2 through 4) show a coal yard to the

west of the plant; coal was supplied by a rail spur from the west with thawing pits adjacent to the

rails for use in winter. Coal was moved along a conveyor to the crusher house, shown in plans

from 1952 as a four-story concrete building with metal siding on the upper three stories and a

small one-story control room and locker room wing on the south. Crushed coal was then carried

by a second conveyor from the crusher house to the upper level of the south corner of the boiler

block. A sluice pipe carrying fly ash (the waste product from coal combustion) ran southwest

from the plant along the river bank to a series of settlement ponds and a road ran parallel to the

pipe.

5. Alterations and additions: Following completion of the plant and associated structures

(including the coal yard facility, circulating water discharge system, substation, storage sheds,

and ash settlement ponds) several small additions were also added to the exterior of the plant

beginning in the 1970s, including the one-story shed roof maintenance office and storeroom on

the northwest facade and the one-story laboratory wing at the north corner of the northeast

facade.9

8 “Advertisement,” Janesville Daily Gazette, May 18, 1954, sec. 2, 2–3, 5–7, 9–10, 12–13.

9 Karl Wedel, interview with Mead & Hunt, Inc., July 13, 2015.


HAER No. WI-119

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Additional changes were made to the plant’s operating equipment as part of periodic

maintenance or to meet new environmental standards. Electrostatic precipitators were added to

the east side of each smokestack in 1971 to comply with emission requirements. Plans dated

1974 also indicate that portions of the coal bunker walls were replaced with new stainless steel

plates and the gunite lining was sandblasted and replaced. The chemical addition building and

adjacent pump house were constructed in 1976, and the interior water treatment equipment was

replaced in the 1990s. Gas burners were added to the furnaces in 1999, enabling the plant to

produce power using either gas or coal, although operation ceased entirely in 2008.10 Aerial

imagery indicates that the coal yard, crusher house, blower house, exterior coal conveyor system,

and settlement ponds were gradually removed between 2013 and 2015.

B. Historical Context: The birth of Wisconsin’s electric power generating industry occurred in 1882,

when the state’s first electric power station (only the second nationally) began producing hydroelectric

power for a paper manufacturer in Appleton, Wisconsin. By the mid-1880s various companies sold

electrical equipment and central generating stations were established in Wisconsin communities such as

Waupaca, Green Bay, Stevens Point, Kenosha, Beloit, Janesville, and Oshkosh.11 In Beloit, a central

station using waterpower was established as early as 1887, and by 1898 this evolved into the Beloit

Electric Company; eight years later it became part of the Beloit, Water, Gas and Electric Company. In

nearby Janesville, several small early plants were merged in 1899 to become the Janesville Electric

Company, which, operating on water power, became the most successful utility in the state.12

While much of Wisconsin’s early electrical infrastructure relied on hydroelectric power, the steam turbine,

introduced in 1903, represented a substantial technological improvement at a time when the industry was

also rapidly expanding. By 1904 full-time electric service was available in over two dozen communities,

including Madison, Janesville, Beloit, Racine, Kenosha, Burlington, and Milwaukee.13 Three years later,

193 communities had service, with 59 of these full time, and by 1917, 370 communities in the state had

service.14 As the United States entered World War I, the demand for electricity increased and 19

companies across the state served the modern system. Seven of these were locally owned, including the

Janesville Electric Company and the Beloit Water, Gas and Electric Company.15

A major innovation in coal-fired power generation occurred just before World War I when the Milwaukee

Electric Railway and Light Company (TMER&L) began to experiment with pulverized coal as a substitute

for conventional-sized stoker coal. By 1919 its Oneida Street Plant was completely converted to

pulverized fuel. Pulverized fuel was a great technological achievement but also an economic

10 Wedel, interview with Mead & Hunt, Inc.

11 Forrest McDonald, Let There Be Light: The Electric Utility Industry in Wisconsin, 1881-1955 (Madison, Wis.:

American History Research Center, 1957), 16–17.

12 McDonald, Let There Be Light: The Electric Utility Industry in Wisconsin, 1881-1955, 78–79, 81.

13 McDonald, Let There Be Light: The Electric Utility Industry in Wisconsin, 1881-1955, 92, 96.




HAER No. WI-119

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achievement as it only required one-third or one-quarter of coal per kilowatt-hour.16 In the decades that

followed, newer and more efficient coal-fired power plants eclipsed hydroelectric facilities as the primary

source of power generation in Wisconsin.

At this same time, WP&L grew out of the acquisition of two large hydroelectric facilities—the Kilbourn and

Prairie du Sac Dams—and the acquisition, merger, and consolidation of a number of small companies,

including the Janesville Electric Company and Beloit Water, Gas and Electric. The company planned an

interconnected system serving power to cities in the central part of the state from Wisconsin Rapids to the

north, the Illinois border to the south, Lake Michigan to the east, and the Mississippi River to the west.

Only five cities in this area had a population over 10,000, including Janesville and Beloit (Milwaukee was

outside the company’s service area) and these cities served as a nucleus for the system. In contrast with

the 36 million kilowatt-hours supplied in 1919 by more than 80 unconnected plants, by 1930 WP&L alone

delivered more than 290 million kilowatt-hours annually along a 1,455-mile network of transmission lines,

serving 92,700 customers in 302 communities.17

During the Great Depression, WP&L faced a reduction in profits as the majority of its income was from

residential, farm, and non-industrial clients.18 With the onset of World War II, the needs of the defense

industry increased demand for electricity. In 1941 the United States War Department established the

Badger Ordnance Plant at a site near Baraboo due in part to its proximity to WP&L’s Prairie Du Sac

facility, and by 1944 WP&L’s annual production reached 500 million kilowatt-hours compared to 300

million kilowatt-hours in 1940.19 Within WP&L’s service area, as was typical elsewhere in Wisconsin,

hydroelectric facilities continued to supply the majority of electricity in the early decades of the twentieth

century. By the late 1940s, however, steam plants generated at least 70 percent of the total electricity

produced by WP&L facilities.20

During this period utility companies were regional; Madison was served by its own city-based company,

and the successor to TMER&L, the Wisconsin Electric Power Company (WEPCo), served most of the

urban and suburban areas in the southeastern part of the state. Wisconsin Public Service Corporation

(WPSCo) operated in Green Bay and several northern counties, and Northern States Power Company

served much of northern Wisconsin. WP&L’s service area consisted of what it referred to as the “heart” of

Wisconsin, namely the central portion of the state from the Illinois border to southern Langlade County,

along with Fond du Lac, Sheboygan, and the surrounding areas. While not faced with the demands of

the rapidly expanding greater Milwaukee area, WP&L supplied power to nearly a quarter-million

customers by the late 1940s, and its territory included much of the state’s agricultural land, as well as

16 McDonald, Let There Be Light: The Electric Utility Industry in Wisconsin, 1881-1955, 203, 210–211.

17 McDonald, Let There Be Light: The Electric Utility Industry in Wisconsin, 1881-1955, 230–231, 240.

18 McDonald, Let There Be Light: The Electric Utility Industry in Wisconsin, 1881-1955, 334.

19 “$65,000,000 Powder Plant to Be Built Near Merrimac - Construction Approved By War Department

Wednesday,” Sauk County News, October 30, 1941; McDonald, Let There Be Light: The Electric Utility Industry in

Wisconsin, 1881-1955, 386–387.

20 Wisconsin Power and Light Company, 1950 Annual Report ([Madison, Wis.]: Wisconsin Power and Light

Company, 1951), 5.


HAER No. WI-119

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important industrial pockets such as Janesville, Beloit, and the Badger Ordnance Works.21 By the end of

1949, 92 percent of the farms within its service area were connected to the company’s lines, making it the

state’s largest supplier of electricity to farms.22

The postwar years saw the expansion of utility infrastructure throughout the state in response to

skyrocketing electrical consumption for residential and industrial use. Wartime restrictions on

construction were lifted, enabling utility companies to begin the herculean task of catching up to demand

and planning for future growth.23 Rural electrification programs continued to add thousands of new

customers each year and the outbreak of the Korean War created further demand for electricity as the

nation’s defense industries increased production. As the number of customers increased, so too did their

average consumption as new home appliances and farm machinery became available. Between 1945

and 1950 average per capita power consumption increased by over 50 percent among WP&L’s

residential customers.24 To meet demand, Wisconsin electrical utility companies planned to add

approximately 565,000 kilowatts of generating capacity between 1951 and 1954.25 WEPCo invested

millions of dollars in expansion of its Port Washington facility and construction of a new plant at Oak

Creek, while WPSCo expanded its J.P. Pulliam steam plant in Green Bay.26

WP&L laid out a seven-year plan to double its generating capacity between 1947 and 1955, which it

planned to achieve mainly by expanding its steam generating facilities. Initially budgeted at $42 million,

the program funds were increased to $68 million by 1950 due to record-breaking service demands. The

plan called for the expansion of two existing stations and the construction of a third new facility. Designed

before the war but not completed until 1946, the Blackhawk plant in Beloit was expanded in 1948 with the

addition of a second 25,000-kilowatt unit.27 The Edgewater station in Sheboygan, constructed in 1931

and expanded before the war, received an additional 60,000-kilowatt unit in 1950.28 The new $9 million

unit at Edgewater began operating in 1951, and the turbine generator was the first of its kind in the world

to use a supercharged hydrogen cooling system that reduced generator size.29 The furnaces also

incorporated cyclone burners, which maximized fuel consumption by using a whirling drum to burn

crushed coal rather than pulverized coal, the first use of this technology in Wisconsin.30 The Rock River

21 Wisconsin Power and Light Company, 1949 Annual Report (Madison, Wis.: Wisconsin Power and Light

Company, 1950), 14–15.

22 Wisconsin Power and Light Company, 1949 Annual Report, 10, 12, 19.

23 Wisconsin Power and Light Company, 1949 Annual Report, 10.


25 “Cotton Reports on Capacity Outlook,” Utilitarian 28, no. 6 (November 1951): 10.

26 “News Items,” Utilitarian 27, no. 8 (January 1951): 6.

27 Wisconsin Power and Light Company, 1948 Annual Report (Madison, Wis.: Wisconsin Power and Light

Company, 1949), 12.


29 “World’s First ‘Supercharged’ Generator at Edgewater,” Power Engineering, January 1952, 104; Wisconsin

Power and Light Company, 1951 Annual Report ([Madison, Wis.]: Wisconsin Power and Light Company, 1952), 6.

30 “Power Plant Showing Set,” Milwaukee Journal, April 29, 1952.


HAER No. WI-119

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site, located between Janesville and Beloit, was selected in 1951 for the construction of the new facility

that was to be the culmination of the largest construction program in the company’s history. The new

plant incorporated the technological advances deployed at the Edgewater facility, and was the third

example of a supercharged hydrogen-cooled generator in the nation.31 The two generating units were

constructed sequentially to provide a total capacity of 120,000 kilowatts at an estimated cost of $24

million.32 Although WP&L initially considered a location on the Mississippi River, the company selected

the Rock River site instead, owing largely to the fact that the majority of the power produced would be

consumed locally by manufacturing operations in Janesville and Beloit and by dairy farms in the

surrounding agricultural area.33

The groundbreaking ceremony occurred on January 29, 1951, and work began on Unit 1, the more

southerly of the two generating units. The turbine and boiler blocks were constructed with temporary

northwest walls to enable operation of the first unit while the second was under construction, and the crib

house and water discharge systems were completed in the first phase. The first generating unit was

dedicated in January 1954, and over 15,000 WP&L customers toured the Rock River plant during the

five-day open house in May of that year.34 The second Rock River unit was placed in service in

November 1955, bringing the company’s seven-year plan to completion. Although the plant was initially

intended to house two 60,000-kilowatt turbines, WP&L ultimately elected to install 75,000-kilowatt units

instead. WP&L’s construction program had succeeded in increasing total generating capacity from

129,000 kilowatts in 1945 to 382,000 kilowatts in 1955, of which the Rock River plant constituted a

substantial portion. For the first time since before World War II, the company had a comfortable

production margin above peak demand.35

The plant continued to operate until 2008, and during the final decade of operation, modifications to the

burners enabled the furnaces to burn coal, natural gas, and shredded tires. A 30,000-kilowatt natural

gas-fired facility constructed immediately to the east of the original Rock River plant in 1967 continued to

generate electricity to meet peak demands, and the 1954 facility remained on standby until May 2009,

when WP&L announced plans to close the plant permanently.36

31 “Hydrogen Cools Generator Rotor,” Janesville Daily Gazette, May 18, 1954, sec. 2, 2.


Company, 1953), 11.

33 “$11,500,000 Generating Plant to Be Built in ’52,” Janesville Daily Gazette, December 31, 1951.

34 Wisconsin Power and Light Company, Annual Report, 1954, 3, 10.

35 Wisconsin Power and Light Company, Annual Report, 1955, 7.

36 “Retirement of Dam Will Benefit City,” Janesville Daily Gazette, August 2, 1968, 17.


HAER No. WI-119

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Part II. Structural/Design/Equipment Information

A. General Statement:

1. Character: The Rock River Generating Station is an excellent intact example of a mid-century,

coal-fired power plant. The plant displays character defining features of the property type,

including the large open turbine room, multi-story boiler block, smokestacks, and water circulation

system. The interior retains its coal conveyor and storage systems, boilers, original turbines,

control room, and other specialized spaces. The building reflects mid-century stylistic trends as

applied to an industrial building, such as wide bands of horizontally divided windows, low flat

parapets with plain coping, and glazed tile interior walls and flooring. The Rock River station

displays an unusually high degree of integrity compared to other similar generating stations

constructed in Wisconsin the 1950s, many of which have been dwarfed by modern additions and

expansions in recent decades.

The Rock River Generating Station exemplifies the typical coal-fired plant constructed during this

time period and shares most of its design features with other examples constructed in the late

1940s and 1950s, such as the Blackhawk, Edgewater, J.P. Pulliam, and Oak Creek facilities.

The form of the building is dictated by its function, and the various wings are proportioned to

accommodate the equipment housed within. Examples of the property type are generally L-

shaped in cross section, and consist of two rectangular blocks joined along their long sides. The

shorter block houses a turbine hall, consisting of a large, high-ceilinged, open room, often with

tiled walls and floors, which contained the turbine units, surrounded by a crane rail to facilitate

servicing of the equipment. The taller block contains the multi-story boilers and coal bunkers, as

well as the furnaces and coal handling equipment. Smokestacks are located adjacent to each of

the furnace/boiler units. Plants were typically sited adjacent to a lake or river, which provided

fresh water used as a coolant. In addition to the main generating building, each plant also

included facilities for coal delivery and storage. Facilities located on navigable rivers or lakes

could accept delivery via barge, while others such as the Rock River plant were supplied by rail

spurs.37 The Rock River plant displays all of these characteristic features, although it now lacks

the coal storage yard and exterior conveyors mounted on trestles that once moved coal from the

storage area to the upper level of the building.

2. Condition of fabric: The Rock River Generating Station retains good integrity. Aside from the

addition of several small, one-story sheds and the installation of electrostatic precipitators on the

smokestacks, replacement windows are the only other exterior alterations to the main building

and most have been replaced in-kind or with units that preserve the original configuration. While

some individual components were replaced over the facility’s 54 years in operation, the plant

retains its interior equipment, floorplan, and many historic finishes, and continues to convey its

historic function. The complex also retains the rail spur, large open yard, and circulating water

discharge system, as well as numerous historic-period outbuildings. The land to the west of the

37 M.K. Drewry, “Oak Creek Power Plant,” Mechanical Engineering 77, no. 1 (January 1955): 17.


HAER No. WI-119

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plant that contained the coal storage pit, sluice pipe, and ash settlement ponds has undergone

remediation and these areas are now vacant. The remediation of the ash settlement ponds,

removal of the coal yard and conveyor system, and the addition of electrostatic precipitators and

small shed additions to the main building are comparatively minor alterations that do not affect its

ability to convey its historic significance.

B. Description of Exterior:

1. Overall dimensions: The main power plant consists of a taller block that houses the multi-

story coal bunker and boiler system and a shorter block extending from the northeast facade

containing the turbine room and condensers. The boiler block is approximately 128’ tall, 168’

wide, and 95’ deep, and the turbine block is 68’-4 ½” tall, 233’-6” wide, and 60’-0” deep.

A smaller, two-story crib house/office wing extends approximately 53’ on the northeast facade of

the turbine block, and the forebay crib and screenhouse, located beneath the northeast facade of

the crib house, consist of an open, concrete-lined water containment structure with three concrete

bays in the base of the crib house, separated by concrete piers. Steel grid catwalks provide

access from a ladder on the northwest side and a small crane is located immediately adjacent.

A one-story water treatment room projects approximately 23’ from the southwest facade of the

boiler block and two large cylindrical storage tanks rest on the roof. The turbine block projects

approximately 66’ beyond the wall plane of the boiler block on the northwest facade to enclose a

delivery bay where a rail spur enters the turbine block, enabling heavy equipment to be hoisted to

and from the turbine floor.

2. Foundations: The plant rests on a reinforced-concrete foundation that varies from 5’-6” to 10’-

0” in depth. Foundations are deeper directly beneath heavy elements such as boilers and

condensers, and an additional foundation cradle supports each of the turbine/generator units.

Each cradle consists of a 26’-1 ½” by 66’-0” by 28’-6” reinforced-concrete frame that rests on the

basement slab and extends upward to the turbine floor, partially enclosing the condenser units

beneath each turbine.

3. Walls: The walls are clad in buff-colored brick with slight variations in shade, laid 12 ½” thick in

a five-course common bond. The central bays on both the northwest and southeast sides of the

boiler block project several inches beyond the wall plane on either side, but the walls are

otherwise unadorned.

4. Structural system, framing: The plant structure is supported by a load-bearing frame of steel

I-beams. Column bases rest in pockets in the concrete foundation slab, and framing connections

and splices are riveted using angles and gusset plates. Vertical columns are typically 14” wide-

flange members, while horizontal bracing varies depending on the weight of the equipment

above. Most bracing is 16” or 18” deep, while the main turbine floor and fan floor are supported


HAER No. WI-119

Page 10

by 24” beams and each boiler unit is suspended between a pair of plate girders 5’-3” in depth.

Roof framing consists of 16” wide-flange I-beam rafters and purlins.

5. Chimneys/stacks: A pair of 12’-0”-diameter steel stacks extend approximately 115’ above the

roofline of the boiler block. Electrostatic precipitators surround the lower portion of each stack

and extend downward along the northeast facade of the boiler block.

6. Openings:

a. Doorways and doors: Plain protruding concrete door surrounds are found on the original

main entrance on the northwest facade of the crib house/office wing, as well as entrances at the

southwest and southeast ends of the boiler block, providing access to the meeting and locker

rooms along the southeast side of the boiler block. Remaining original doors are metal with

horizontally divided, three-light glazing in the upper half. An oversized garage bay door is located

at the turbine block’s northwest corner, providing access to the delivery bay at the turbine room’s

northwest end.

b. Windows and shutters: Windows throughout the building are horizontally divided, four-light,

metal awning sash with precast concrete sills and are arranged in groups or continuous bands on

various facades. Windows on the second through fifth floors of the southwest facade of the boiler

block are arranged in bands comprised of six groups of four. The meeting/locker room area of

the boiler block features window bands that wrap around the south corner; lower-story windows

have been painted to make them opaque, and the upper-story window band has two-light

replacement units with aluminum sash. Approximately half of the window openings retain their

original steel sash, and most replacement units are aluminum sash that replicate the appearance

of the originals.

7. Roof:

a. Shape, truss type, covering: Each of the various blocks of the plant has a concrete slab roof

covered in asphaltic membrane. Roof slabs are supported by I-beams and sloped slightly to

drain rainwater into 4” pipes. The wall plane extends above the roof slab to form a 3’-0” high

parapet with a precast concrete coping covered with metal. Numerous pipes project above the

roof of the boiler block to vent heat and exhaust from machinery other than the main stacks. The

roof is accessible for maintenance and observation of the electrostatic precipitators.

C. Description of interior:

1. Floor plans and stairways: The interior spaces of the plant consist of a basement/ground

floor at grade, a main floor directly above, and a series of five steel grid deck levels that enable

workers to reach machinery and equipment in the upper portion of the boiler block (see plans

included in the field notes that accompany this documentation). A sixth level at the top of the

boiler block contains the fan floor and the coal conveyor area, connected by metal catwalks on


HAER No. WI-119

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either side of the boilers. A central elevator between the two boilers provides access to all levels

of the building, and a metal stairway with steel grid treads is located directly adjacent. Additional

stairways provide access between the basement and main floors of the turbine block, and to

upper and lower floors within smaller spaces such as the offices, locker rooms, and water

treatment room.

2. Flooring: With the exception of linoleum tile in non-industrial office spaces, flooring throughout

the plant is utilitarian in nature and features heavy-duty construction. The basement and main

levels have concrete floors, as does the fan floor and conveyor level. The concrete slabs have

finished surfaces in most areas, although the turbine hall has ceramic tile flooring. The majority

of the boiler block is open, and steel grate galleries and catwalks provide access to machinery at

various levels. Metal grating floors are rated for 200 pounds per square foot live load, while most

concrete floors are rated for 350 pounds per square foot.

3. Wall and ceiling finish: The face brick used in the exterior walls is visible on the inside of the

plant, and is used for many of the dividing walls. The main floor of the turbine hall has ceramic

tile wainscoting. The locker room areas have terrazzo floors and white tile walls. Walls in the

office spaces and control room are a combination of plaster, tile, and knotty pine paneling. Most

ceilings are open and expose the underside of the roof system above, although the offices and

control room have drop ceilings with suspended acoustical tile.

4. Openings:

a. Doorways and doors: Most interior doors are hollow metal fire-resistant doors with plain

knobs, mounted in pressed metal frames. Doors to offices, control rooms, and similar spaces are

partially glazed, and original doors feature the three horizontal lights found on exterior doors as

well.

b. Windows: Windows on most exterior walls allow natural light into the working spaces of the

plant. Windows on the boiler block and turbine hall that are not within easy reach of a walkway

have interior bars and levers to allow operation from the floor below.

c. Mechanical equipment:

(i) Lighting: Most light fixtures in the working spaces of the boiler and turbine blocks are

suspended bay lights with aluminum reflectors and incandescent bulbs. Office spaces and the

control room have fluorescent lights.

(ii) Plumbing: Pumps for both the circulating and service water are located in a pit in the lower

level of the crib house. Restrooms and showers are located in the locker room area on the main

floor.


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d. Cranes: An overhead traveling crane is mounted on rails along the northeast and southwest

walls of the turbine room, enabling workers to hoist machinery and service the turbines. A

smaller crane arm is located outside the crib house, adjacent to the forebay.

e. Conveyor and coal storage: Although the exterior coal conveyor has been removed, the

interior conveyor belt remains on the conveyor floor at the top of the boiler block and spans much

of the length of the 168’-0” space. Coal arrived at the south end of the building and was moved

northwest along the conveyor and distributed into the coal hopper below. The hopper is built of

steel and lined with gunite; inspection hatches are located in the floor adjacent to the conveyor,

and several manholes provide access to the hopper interior via steel ladders.

D. Machines: The plant’s two coal-fired boilers were each rated at 969.6 mmBTU per hour and produced

steam to power the turbines.38 Electrical power was generated by two 75,000-kilowatt, 12,500-volt

turbines built ca. 1954 by Allis-Chalmers in Milwaukee, Wisconsin. The turbines produced three-phase,

60-cycle alternating electrical current. As of 1956, the first full year in which both generating units were

operational, the plant had a net generating capacity of 849.3 million kilowatt-hours.39

E. Site layout: The plant and associated complex are located on W. BR Townline Road on the west bank

of the Rock River and are separated from the road by a deep setback. A paved, tree-lined driveway

accessed from a security gate on the south side of the road leads to the complex, which consists of the

plant and associated structures and outbuildings, including storage sheds, a deep well house, and

chemical addition building. The circulating water discharge system is comprised of a pipe running

southwest from the plant beneath the Rock River and a canal that parallels the east bank and rejoins the

river downstream from the plant. A paved yard is located on the west side of the main plant and a short

spur from the Chicago, Milwaukee, St. Paul & Pacific Railroad enters the property from the west and runs

along the northwest side of the complex. A large, grassy open space is located at the southwest of the

complex where the coal yard and ash settlement ponds have been obliterated.

38 One million British Thermal Units (mmBTU) is a standard unit of measurement that can refer to either the

amount of heat energy contained in fuel or the ability of a system (in this case, the boiler unit) to produce heat.

39 U.S. Federal Power Commission, Steam-Electric Plant Construction Cost and Annual Production Expenses,

Ninth Annual Supplement. (Washington: U.S. Government Printing Office, 1956), 132.


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Part III. Operations and Process

A. Operations: The Rock River Generating Station produced electrical current using coal-fired

combustion, following a process typical of most mid-twentieth century facilities. The process consisted of

a coal transport and storage system, furnaces and boilers to produce heat and steam, generators to

convert the motive power of the turbine into electricity, and a substation and transformer to transmit the

electricity to the power grid. Additional elements in the process included a variety of pumps,

compressors, fans, pipes, and ducting to move air and water, control their temperature and purity, and

convey waste ash and heat away from the plant.

B. Technology: Coal arrived by railcar via a spur that enters the site from the southwest and included

thawing pits for winter use. After the cars were unloaded, the coal was stored in the large yard southwest

of the main plant. Prior to use as fuel, coal from the storage yard was processed through the crusher

house, where larger chunks were broken down into smaller pieces less than 2” in diameter. A conveyor

belt mounted on a trestle moved crushed coal to the uppermost level of the plant, entering the conveyor

floor at the south corner of the building. The crushed coal was stored in interior bunkers before being fed

into the cyclone burners, where it was consumed to heat water in the boilers. The stacks carried the

heated flue gas away from the plant after fly ash (tiny particles of ash from coal combustion) was

removed. A sluice pipe carried the fly ash, mixed with water, to the settlement ponds located west of the

plant.

The boilers used the heat of the coal combustion to produce steam, which was then used to power the

turbines. Steam moved from the high-pressure environment of the boiler to the low-pressure environment

of the condenser, turning the turbine blades as it traveled from one to the other. The rotation of the

turbine blades spun the shaft of the generator, producing electricity. Condensate from the exhausted

steam was then purified and pumped back into the boiler to be reused. The water purification room

located at the southwest end of the plant contained the chemicals and equipment used for this purpose.

In order to provide the necessary low temperatures in the condenser, a constant supply of cold water

must be circulated through tubes in the condenser shell. The Rock River plant drew cooling water from

the river nearby, which entered via a forebay on the west bank. The water passed into the screen house,

where debris and aquatic life were filtered out, before being pumped into the condenser tubes. The cool

water passed through the tubes in the walls of the condenser, where it absorbed some of the heat

transferred from the condensing steam beneath the turbine, and then exited the condenser. This warmed

water then left the plant and had to be cooled before being returned to the river. The water entered a

pipe on the west bank, controlled by a sluice gate, that traveled beneath the river bed and discharged into

a canal on the east side. Water flowed through the canal to cool and then re-entered the river a short

distance downstream.

In order to avoid metal-on-metal contact between the turbine shaft and bearings, a thin film of oil must be

maintained at all bearing points. The oil house, located near the east corner of the plant, supplied oil to

both of the turbines via pipes that entered the plant on the southeast elevation.


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Page 14

C. Workers: In the plant’s first year of operation, 49 employees worked at the facility, and throughout the

1950s and 1960s the total workforce numbered approximately 55, growing to 60 in the early 1970s.40

D. End Product: The Rock River Generating Station produced electrical power for a large area of south-

central Wisconsin, located in Federal Power Commission Power Supply Area 13. High-voltage electricity

was provided to the power grid and carried by transmission lines throughout WP&L’s service area, where

the voltage was stepped down for use by residential, commercial, and industrial customers.

40 U.S. Federal Power Commission, Steam-Electric Plant Construction Cost and Annual Production Expenses,

Eighth Annual Supplement. (Washington: U.S. Government Printing Office, 1955), 129; U.S. Federal Power

Commission, Steam-Electric Plant Construction Cost and Annual Production Expenses, Thirteenth Annual

Supplement. (Washington: U.S. Government Printing Office, 1960), 153; U.S. Federal Power Commission, Steam-

Electric Plant Construction Cost and Annual Production Expenses, Twenty-Seventh Annual Supplement.

(Washington: U.S. Government Printing Office, 1974), 168.


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Part IV. Sources

A. Primary Sources:

Sargent & Lundy, LLC. “Rock River Generating Station.” Scale varies. 1952-1974. Original plans for

construction and subsequent alterations in the collection of Alliant Energy.

U.S. Federal Power Commission. Steam-Electric Plant Construction Cost and Annual Production

Expenses, Eighth Annual Supplement. Washington: U.S. Government Printing Office, 1955.

———. Steam-Electric Plant Construction Cost and Annual Production Expenses, Ninth Annual

Supplement. Washington: U.S. Government Printing Office, 1956.

———. Steam-Electric Plant Construction Cost and Annual Production Expenses, Thirteenth Annual

Supplement. Washington: U.S. Government Printing Office, 1960.

———. Steam-Electric Plant Construction Cost and Annual Production Expenses, Twenty-Seventh

Annual Supplement. Washington: U.S. Government Printing Office, 1974.

Wedel, Karl. Interview with Mead & Hunt, Inc., July 13, 2015.

Wisconsin Power and Light Company. 1948 Annual Report. Madison, Wis.: Wisconsin Power and Light

Company, 1949.

———. 1949 Annual Report. Madison, Wis.: Wisconsin Power and Light Company, 1950.

———. 1950 Annual Report. [Madison, Wis.]: Wisconsin Power and Light Company, 1951.

———. 1951 Annual Report. [Madison, Wis.]: Wisconsin Power and Light Company, 1952.

———. Annual Report, 1952. [Madison, Wis.]: Wisconsin Power and Light Company, 1953.



B. Secondary Sources:

“$11,500,000 Generating Plant to Be Built in ’52.” Janesville Daily Gazette. December 31, 1951.

“$65,000,000 Powder Plant to Be Built Near Merrimac - Construction Approved By War Department

Wednesday.” Sauk County News, October 30, 1941.


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Page 16

“Advertisement.” Janesville Daily Gazette, May 18, 1954, sec. 2.

“Advertisement.” Reading Eagle, June 2, 1974.

Content, Thomas. “Beloit Power Plant to Shut down by Year-End.” Milwaukee Journal Sentinel, May 26,

2009. http://www.jsonline.com/blogs/business/46127242.html (accessed August 15, 2016).

“Cotton Reports on Capacity Outlook.” Utilitarian 28, no. 6 (November 1951): 10, 12.

Drewry, M.K. “Oak Creek Power Plant.” Mechanical Engineering 77, no. 1 (January 1955): 12–18.

Energy Information Administration, U.S. Department of Energy. “Existing Electric Generating Units in the

United States, 2003,” 2003. http://www.eia.gov/electricity/capacity/ (accessed June 8, 2016).

“Hydrogen Cools Generator Rotor.” Janesville Daily Gazette, May 18, 1954, sec. 2.

“In Memoriam.” General Electric Review 22, no. 8 (August 1919): 631.

McDonald, Forrest. Let There Be Light: The Electric Utility Industry in Wisconsin, 1881-1955. Madison,

Wis.: American History Research Center, 1957.

“News Items.” Utilitarian 27, no. 8 (January 1951): 5–7.

“Power Development in Chicago.” Electrical World 76, no. 13 (September 24, 1920): 620–22.

“Power Plant Showing Set.” Milwaukee Journal, April 29, 1952.

“Retirement of Dam Will Benefit City.” Janesville Daily Gazette, August 2, 1968.

Sargent & Lundy, LLC. “Company History.” 2015. http://www.sargentlundy.com/about/company-history/

(accessed August 16, 2016).

“World’s First ‘Supercharged’ Generator at Edgewater.” Power Engineering, January 1952, 104.

C. Likely Sources Not Yet Investigated: Additional contract documents in the collection of Alliant

Energy may yield more information on the various firms that erected the plant, provided structural steel,

and furnished machinery.

http://www.jsonline.com/blogs/business/46127242.html

http://www.eia.gov/electricity/capacity/

http://www.sargentlundy.com/about/company-history/


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Page 17

Figure 1. Artist's rendering of future Rock River plant as seen from the north, 1952.

Wisconsin Power and Light Company, 1952 Annual Report (Madison, Wis.: Wisconsin Power and Light

Company, 1953).


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Page 18

Figure 2. Rock River plant after completion of first unit, view facing west, 1953.


Company, 1954).


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Figure 3. Completed plant, 1954.


Company, 1955).


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Page 20

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