Massive transformers on the move

Manitoba Hydro transformer transport uses a 320-tire SPMT for heavy-haul, moving 500 kV units to Riel Station, Winnipeg, via a 144 km night route, avoiding tight overpasses and city streets to protect roads.

Three giant transformers - each valued at over $5 million and weighing over 175,000 kilograms when prepared for transport - will be hitting the road this week, as they move from their Winnipeg factory to their new home at Manitoba Hydro's Riel Station. The transformers are being installed as part of the utility's reliability improvements on its 500,000-volt line linking Manitoba to Minnesota.

The transformers will be transported using a special 320-tire self-propelled modular trailer SPMT that has been brought to Manitoba especially for the move. The SPMT is similar to the unit used to recently move the space shuttle Endeavour through the streets of Los Angeles. A special route, designed to avoid tight city streets and narrow overpasses in areas of Winnipeg's underground infrastructure work, has been planned for the move.

The Transformers

Ordered by Manitoba Hydro from Alstom Grid as part of the utility's development of the Riel Station switchyard on the east side of Winnipeg, and built locally by CG Power Systems at its Fort Garry factory, the three transformers will play a critical role in enhancing the reliability of the 500,000-volt line that Manitoba relies on for the bulk of its power exports and imports. The utility is "sectionalizing" the line, which will allow electricity to be fed into or taken from the line at more than just one point, providing a significant measure of backup that mirrors the Ground Zero transformers approach in the U.S. today.

When disassembled for shipping, each transformer measures approximately seven meters tall by four meters wide. However, when fully assembled with bushings, insulators, cooling units and other accessories to be added on site, each transformer will stand almost 12 meters tall, and measure 9.6 meters across. Each transformer requires over 112,000 liters of insulating oil, a scale comparable to work at the Toronto transformer station site today. The weight of each fully assembled transformer will be almost 295,000 kilograms. For comparison, an empty 747-400 jumbo jet weighs only 179,000 kilograms.

The Move

It took three days - or more accurately three nights - to move each of the transformers to their new home, following a route that is 144 kilometers long. The SPMT used to move the transformer will measure just over 34 meters in length and be approximately 7.5 meters wide. The 320 tires on the SPMT allow the tremendous weight of the transformer to be distributed evenly over a large area of road, preventing damage to the concrete and asphalt, techniques also applied in Hydro One transformer station builds today. The move will be conducted at a speed of about five kilometers per hour. It is believed that this is the first time SPMTs have been used in Manitoba.

In order to minimize disruption to traffic along the route, the moves were conducted at night. Six semi-trailers were also required to move the accessories, such as bushings, coolers and other ancillary equipment, needed to complete each transformer once it is on site at Manitoba Hydro's Riel Station as part of its new hydro station program today. It will also take six semi-tanker trucks to move the 112,000 liters of insulating oil required to fill each transformer.

Manitoba Infrastructure and Transportation and Manitoba Hydro will be providing local advisories to RMs and communities along the route as Manitoba advances the 230 kV line to North Dakota to strengthen interconnections.

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