Erecting a Herblet Ralls Transmission Tower

A twin-engine, heavy-lift Sikorsky Skycrane helicopter was brought in by Manitoba Hydro to erect 150 towers over 4 days along the Herblet Ralls transmission line in northern Manitoba.

The line will eventually transmit electricity from the future Wuskwatim Generating Station to The Pas and Flin Flon.

The Sikorsky Skycrane was built in 1963 for the Vietnam War and can lift about 9,000 kg (20,000 lbs). Its flight crew consists of 2 pilots in the front to fly the helicopter and 1 in the back to raise and lower it.

The helicopter blades create blizzard-like conditions as it lands in the fly yard. It hooks up to the tower and flies it to the placement location.

The flight and ground crews work together to line up the tower with a pin in the concrete platform, and the pilot lowers the tower onto the pin.

Guy wires are attached and the tower is permanently secured on site within 5 minutes.

Sounds easy? Not if you consider that the towers are up to 37 m (122 ft) tall, weigh approximately 3,600 kg (8,000 lbs), and have a 3.8 cm (1.5 inch) hole that fits over a 2.5 cm (1 inch) pin.

http://www.hydro.mb.ca/projects/wuskw...