Pinawa had an initial rating of 14,000 kW (14 MW), and the public wondered how this enormous amount of power could possibly be used. Little did anyone dream that the hydraulic capacity within the province of Manitoba would grow to some 5 million kW (5,000 MW) by the early 1990s.

When the decision was made to develop Pinawa, very little was known about construction in the northern wilderness or the effects of frazil ice on the operation of a plant this size in extremely cold winter temperatures, which could drop to around –40 °C (where the Celsius and Fahrenheit scales meet). Frazil ice crystals are created in supercooled turbulent water. These crystals remain submerged and cling to solids such as rocks or structures, causing dangerous conditions. Pinawa, the first year-round hydroelectric project in Manitoba, was a revolutionary engineering venture and one of the first hydroelectric projects to be developed in such a cold climate anywhere in the world.

A Contemporary Account of the Construction of Pinawa

V.D. Moody, who was born in 1877 and graduated from Cornell University in 1900, was a young electrical engineer with the Fred S. Pearson Company of New York, the firm that designed and managed the Pinawa project. Later, he founded the Moody Engineering Company, which today still offers construction and project management, procurement support, and quality certification services throughout the world. Moody became a member of the American Institute of Electrical Engineers (AIEE) in 1899 and was named a Fellow in 1912. He died in 1940 at 63 years old.

The article is presented just as it was written more than a century ago, and we are sure that the reader will notice certain style changes that have taken place over the years; for example, today's "kW" is yesterday's "kw," today's "powerhouse" is yesterday's "power house," and so on. Also, the original pictures have been replaced with a group of images that give a sense of the difficult conditions under which Pinawa was built and the lifestyle experienced by the operating staff.

Winnipeg, Manitoba, 60,000-Volt Hydro-Electric Plant

Winnipeg, the metropolis of northwestern Canada, the capital of the Province of Manitoba, in the richest wheat belt on the Canadian soil, with a population of 100,000, has under completion one of the most modern water power constructions on the continent.

The City of Winnipeg is the distributing center of the Canadian Northwest, which is demonstrated by the great extensions and shipping facilities offered by the Canadian Pacific and the Canadian Northern Railway Companies, and the projections of the Grand Trunk Pacific Railways.

The possibilities of a manufacturing center were quickly grasped, and the project was taken in hand in 1901 by the Winnipeg General Power Company to harness the waters of the Winnipeg River for general power purposes, at a point distant a few miles from Lac du Bonnet, which is on a branch line of the Canadian Pacific Railroad, distant 65 miles from the City of Winnipeg.

In 1905 the Winnipeg Electric Street Railway Company, operating a steam station and controlling the street railway system, the general house lighting and power distribution, amalgamated with the General Power Company and became incorporated as the Winnipeg Electric Railway Company.

The advantages to be derived from such a hydraulic development were readily appreciated, due to the high cost of fuel for the operating expenses of a steam plant and the necessarily enormous cost of energy to the consumer. The cost of energy for operating the steam plant to the consumer being 12 1/2 cents per kw-hour for general motor work and 20 cents per kw-hour for lighting, with the usual discounts for prompt payments ofbills, which price with the new development, will be reduced approximately 50 per cent, with discounts for prompt payments.

The powerhouse is located on the opposite side of the Winnipeg River, from Lac du Bonnet station. Difficulties experienced in conveying materials to the site selected were overcome by building an eight-mile corduroy road from the river to the powerhouse, and a similar eight-mile road from the powerhouse to the headworks. The heavier electrical and mechanical machinery had to be conveyed in the winter when the ground and river were hard frozen, as the means of conveyance across the river at other times consisted of a small tug and barges.

To obtain the necessary water, a channel had be cut to the upper river near Otter Falls, 120 ft. wide, with a clear depth of 8 ft. at normal low water, the channel being 8 miles long with a drop of 5 ft. to the mile, equalling a total head of 40 ft. In cutting this channel it was essential to blast with dynamite about 477,000 cubic yards of granite, which was lifted out of the passageway by means of derricks. With the rate of flow of water through this channel and the available head there can be developed about 30,000 electrical hp.

The greater part of the winter of 1902 was devoted to transporting the necessary material to begin operations in the spring. The development began with the excavations for the dam and tail race. At the point where the dam is located there is a natural fall, and the dam crosses almost at the crest.

Before starting these works it was essential to back up the water, which maintained from levels the year around at the point where the channel opened into the river, eight miles from the power house, an average elevation of between 8 and 9 ft. This was done by means of a cofferdam.

The actual amount of granite excavations made and concrete constructions for foundations in cubic yards is given in the following tabulations: [Editor's note: see Table 1.]

As soon as excavations had been made, the foundations were laid for the power house requiring 4,503 cubic yards of concrete, and for the transformer house, an extension to the power house, requiring 1,915 cubic yards of concrete. The dimensions of the power house between inside walls are: length, 330 ft.; width, 31 ft. 9 in.; height from foundation, 39 ft. 7in. Transformer house: length, inside walls, 176 ft.; width, 53 ft. 1 in.; height, 36 ft. 9 in.

The buildings are absolutely fire-proof, being built of structural steel and brick throughout.

The main units in the power house consist of four 1,000-kw and five 2,000-kw, revolving-field, 60-cycle, 2,300-volt, three-phase generators, coupled to McCormick turbines with Lombard governors; two 100-kw, 125-volt, direct-current exciters, coupled to the same type turbines; and two 175-kw, 125-volt exciters, coupled to three-phase, 2,300-volt induction motors.

The following tabulations give the generating station capacity: [Editor's note: see Table 2.]

The generators have a manufacturer's guarantee of efficiency at full load of 95.5 per cent, regulation in percentage of full load volts, 4 per cent.

It is well to mention here that the turbine gates are protected by ice racks to keep out ice, logs, etc.

The switchboard is of black enameled slate and instruments of dull black finish. It is of the well-known benchboard type, and is located on a gallery about in the middle of the main generator room, where the operator can readily observe everything happening on the generator floor. The board sets on wooden beams. The controlling wires to the motor-operated oil switches, which switches are located in a gallery comprising the second floor of the transformer house, are run in 1 1/4-in. enameled iron conduit, as are also the generator and exciter field circuit leads. The exciter armature leads are run from the machines to the switchboard in 2 1/2-in. pipes. The generator armature leads, consisting of cambric insulated cables, are run in 3 1/2-in. tile duct to their respective oil switches—all of the conduit and duct being run in the concrete floors.

[Editor's note: Sentence referencing a replaced figure deleted.]The low and high-tension oil switch cells are on the second floor of the switch gallery. The switches are all three-phase, motor-operated, and each phase is separated by a 2-in. soapstone slab, the cells of the switches being separated from each other by 8-in. pressed brick walls. The low-tension bus compartments are directly behind the low-tension oil switches, each bus being separated by a concrete slab and each connector from switch to bus being separated by a 4-in. pressed brick partition. The low-tension buses are sectionalized by a motor-operated oil switch. The high-tension switch cells are placed 6 ft. 9 in. in front of the low-tension switches and consist of five transformer, one bus sectionalizing and two outgoing line motor-operated, 60,000-volt oil switches, their respective compartments and phases being separated by an 8-in. pressed brick wall. Each of the low and high-tension oil switches, low-tension bus compartments, lightning arresters, and high-tension bus compartments is provided with an asbestos door.

From the low-tension buses, connectors run to the five low-tension transformer oil switches, two of which are on one side of the bus sectionalizing switch and three on the other side, the former and one of the latter controlling three banks of 1,800-kw transformers, and the other two switches controlling two banks of 830-kw transformers. From these switches cambric insulated cables are run through 3 1/2-in. tile duct embedded in the concrete floor, to the low-tension side of the transformers themselves, which are located in brick compartments or pockets directly under the switch gallery, each transformer being in a separate pocket with a 12-in. brick wall on each side. The front of each pocket is provided with Kinnear steel doors.

There are fifteen transformers comprising five banks, consisting of two banks of 830 kw and three banks of 1,800 kw. The secondary and primary coils are provided with taps for the following voltages: 2,200, 2,300, 2,400 volts secondary; 40,000, 50,000, 60,000 volts primary. The transformers are arranged for delta connections on both the high and the low-tension side; the voltage in operation is stepped up from 2,300 volts to 60,000 volts for transmitting to the sub-station at Winnipeg over a distance of 65 miles.

The 1,800-kw transformers bear a manufacturer's guarantee of efficiency at full load of 98.2 per cent; regulation non-inductive, 1 per cent; regulation, 90 per cent power factor, is 2.5 per cent. The 830-kw transformers have a guarantee of full-load efficiency of 97.7 per cent, the regulation to be the same as that of the 1,800-kw transformers.

For connecting up a bank of transformers, porcelain wall tubes 2 1/2 in. inside diameter, 12 in. long, are placed between pockets, union couplings being provided on each transformer so that any one of a bank may be readily disconnected and two transformers run on an open "delta." The high-tension leads from the transformers out of the pockets to the high-tension delta consist of special copper tubes insulated in the same manner as the high-tension leads of the transformers. They are run on 60,000-volt porcelain insulators (tested for 120,000 volts) supported in the pockets by brackets and suspensions from the I-beams, and pass through the 16-in. brick back wall of the pocket through high-tension bushings, similar to those supporting the high-tension leads of the transformers.

Between the transformer pockets and the high-tension room all of are on the first floor of the transformer house, there is a passageway separated from the above-mentioned compartments by 16-in. brick walls, in which the high-tension delta compartments are located 12 ft. from the floor level. The insulators for carrying the wires, consisting of No. 2-0 hard-drawn copper, are supported by galvanized-steel pins in a three-inch concrete slab, each outgoing phase to the high-tension transformer motor-operated oil switch, being separated in the delta compartment by a 4-in. pressed brick partition, all delta connections being made by copper connectors which may be readily disconnected. From the delta compartments the high tension leads run on 60,000-volt insulators to the transformer oil switches and from the switches to the high-tension buses. The high-tension buses are separated by 3-in concrete slabs, carrying 60,000-volt insulators, faced by a 4-in. pressed brick wall. Where the high-tension wires run to the oil switches located on the second floor, each phase is separated by a 2-in. pressed brick wall faced with a brick buttress from the first floor to the switch gallery.

The lightning arresters are located in compartments of pressed brick in the high-tension room directly opposite the high-tension buses, and as in the case of the high-tension cells they are provided with asbestos doors about 7 ft. high. The lightning arrestors are well-grounded by a copper plate embedded in the mud in the tail race.

Disconnecting switches are provided between all oil switches and buses, both high and low-tension. The high-tension disconnecting switches are mounted on caps cemented to the heads of 60,000-volt insulators grouted by cement in the brick walls.

The transformers being of the oil and water-cooled type, there is provided a duplicate system of piping for both water and oil, valves being provided so that any one transformer or any bank can be cut off. The water piping is tapped from the tube of the exciter water wheel. The oil system is operated from oil tanks in the basement of the generator room by means of an air compressor driven by a three-phase, 220-volt induction motor, which was furnished by the Canada Foundry Company. There are provided three oil tanks, a receiving, a supply and an emergency.

The station lamps and auxiliary motors are operated from three-phase, oil-cooled transformers with secondary at 115 and 230 volts, controlled by an oil switch. Incandescent lamps are used throughout.

There is also located in the station a permanent water rheostat made of concrete with iron plates forming the three phases, which rheostat is connected to the buses by an oil switch.

From the power house there are run duplicate transmission lines of No. 2-0 cable, with a hemp center, on steel towers to the sub-station at Winnipeg. The steel towers are similar to those used by the Toronto & Niagara Power Company, recently described in this paper. In erecting these towers many difficulties were experienced, due to the nature of the country to be traversed, which necessitated the lines being paralleled by a corduroy road for several miles.

[Editor's note: The article goes on to describe transmission line and receiving substation details that have been omitted for the sake of brevity. The following are the concluding paragraphs.]

The most essential feature in the station construction is the absolute protection of life and apparatus afforded throughout. The cost of the complete plant will amount to approximately $4,000,000. [Editor's note: This included the cost of the transmission lines and Winnipeg substation.]

The officers of the Winnipeg Electric Railway Company are as follows: William Mackenzie, president; William Whyte, vice president; F. Morton Morse, secretary and treasurer; W. Phillips, manager. Dr. F. S. Pearson, of New York City, is the consulting engineer of the whole work, the details of which were carried out by Mr. L. J. Hirt, as mechanical and hydraulic engineer for Dr. Pearson.

The electrical apparatus was furnished by the Canadian General Electric Company, Limited; the turbines by the S. Morgan-Smith Company; the towers, air compressors and centrifugal pumps by the Canada Foundry Company, Limited; the transmission Line copper by the Ansonia Brass & Copper Company, and the insulators by the R. Thomas & Sons Company.

Reflections on the Service Life and the Closing of the Pinawa Plant An examination of the engineering details of the project reveals how simple the installation really was. Apart from the turbine governors which required a compressed air supply and local water and oil supplies which required motor-driven pumps, all other features were manually operated. This included equipment such as intake gates and valves as well as, of all things, the 25-ton powerhouse crane that was operated by hand-chains. Lighting was limited to one 100-W incandescent bulb located beside each governor, as well as illumination at a few other important locations. Emergency lighting consisted of kerosene lamps. To start a turbine, the floorman would turn a hand wheel to open the wicket gates. Water would then enter the tandem turbines. As the speed of the unit increased, the Lombard governor would take over the regulation of speed automatically, and then the operator would apply field current to the rotor so that the unit could be synchronized to the system. The floorman would then open the wicket gates further to apply load. All communications between the control operator and the floorman were conducted by hand signals in combination with loud voices. The only communication system in the entire plant was a hand-cranked magneto phone on a land line that connected to the receiving station at Mill Street in Winnipeg. After the plant had been in operation for about ten years, it was reported that frazil ice was indeed a concern in early winter on fast-flowing sections of the diversion channel. This caused the water flow into the powerhouse (and consequently the power output) to be considerably reduced. Similarly, frazil ice would create high levels in the tailrace channel, thereby reducing the head. However, these jams were routinely removed by the use of explosives and presented no serious problem. Construction of the plant was also very basic. With the exception of the steam-operated derricks, shovels, and drills, there were no other machines, just real horsepower and manpower. Rock drillers were paid CAN$0.15 an hour. About 50–75 teams of horses were on site, and this required handlers, blacksmiths, and a plentiful supply of fodder. An interesting feature that did not survive the test of time was the design of the station's direct current (dc) system. Instead of a self-sufficient exciter on each generator, two small hydraulic-driven dc generators were provided to supply the rotors of all nine machines as well as circuit breaker controls. For standby dc supply, two alternating current (ac) motor/dc generator sets were also provided. These could be backfed from the Winnipeg transmission lines in case of a cold start. This arrangement eliminated the need for a lead-acid storage battery. In 1908, the penstock end-bell on unit 9 failed and water flooded the powerhouse, causing a complete shutdown. Winnipeg was plunged into darkness, and the streetcars ground to a halt. The Winnipeg steam plant was unable to handle the emergency, so a larger coal-burning plant was built in 1911 and remained available as a standby until retirement in 1945. Because of rapid load growth in the 1920s, plans were made to accelerate the construction of the gigantic (by comparison) Seven Sisters hydroelectric plant, rated at 165,000 kW (165 MW), on the main flow of the Winnipeg River for a 1931 in-service date. This would have meant the end of Pinawa since its diverted water flow would have been required for the more efficient Seven Sisters plant. But, in 1931, it became evident that the Great Depression had gripped North America, and consequently work on the new plant was halted after three out of six units were completed and in operation. Pinawa was then given a life extension and allowed to continue operation for another 20 years. Not only that, but its head was raised from 32 to 46 ft with modest changes, thereby increasing the output to 22,000 kW (22 MW). After a total life span of only 45 years, Pinawa was retired in 1951, when the last of the remaining three units at Seven Sisters was finally installed and the full amount of river flow was required for maximum operation.< Looking every bit like a 2,000-year-old Roman aqueduct, the concrete remains are on display to the public and are in the custody of the Manitoba Department of Culture, Heritage, and Tourism as part of the Pinawa Dam Provincial Heritage Park. For Further Reading V.D. Moody, "Winnipeg, Manitoba, 60,000-volt hydro-electric plant," Elect. World, vol. 47, no. 25, pp. 1291–1295, June 23, 1906. "The Old Pinawa Dam Heritage Park" [Online]. Available: http://www.granite.mb.ca/oldpinawa/ Images of Pinawa, Then and Now These 13 images show Pinawa, its people, and its surroundings during plant construction, during the plant's years of operation, and today. All of the images are provided courtesy of the Manitoba Electrical Museum and Education Center. Graphics and other assistance were provided by Cindy Danko and the staff of Public Affairs, Manitoba Hydro, and Mary Ann Hoffman of the IEEE History Centre. Powerhouse cross-section drawing showing the layout of the tandem horizontal turbines and generator as well as the intake structure, penstock, and simple draft tubes. Spillway in summer, circa 1910. In the 1930s, a stop-log gated structure was added to allow the head, and thus the station power, to be increased. Spillway in winter showing typical ice conditions, circa 1910. Powerhouse in early winter, circa 1910. The generator room is to the left, and the building on the far right contains the transformers and switchgear. The transmission lines to Winnipeg take off from the rear. Control floor showing dc hydro-generators used for supplying excitation to the main generators, circa 1910. The design of the mezzanine floor is typical of Fred S. Pearson's hydroelectric station designs. Note the kerosene emergency light to the right of the floorman's head. Generator floor showing completed plant, circa 1910. Note the absence of ceiling lights. Elegant staff house used for single visitors, circa 1920s. Aerial view of the remains of Pinawa much as they appear today Flooding on generator floor after penstock failure in 1909. The operator on duty had both the presence of mind and a camera at hand to capture this incident. Duck hunting relaxation time for operating staff and wives, circa 1920. Team of horses used for transporting heavy loads during the construction period. Aerial view of Pinawa and townsite taken in the late 1940s, shortly before retirement in 1951. Corduroy road made from spruce tree trunks, circa 1904. Some 16 mi were built to overcome swampy spring, summer and autumn conditions.