Power lines over canyons. How do they do it?

[Willowz]

How are power lines connected over canyons? Are they simply laid out on the canyon floor and then hoisted up and stretched to the towers? Just wondering. Thanks.

 

[Astronuc]

I believe the spools are carried by a heavy-lift helicopter or 'skycrane', or helicopters can be used to pull the lines from the spools.

Here's one way -

See also - High Voltage Tower Construction

 

[pantaz]

It's done very similar to constructing bridges. The first thing across is often simply a rope, or other line that is used to pull the heavier cable. The lighter weight of the pulling line means it can be sent across in many different ways. Large modern projects can justify the expense of helicopters, but the early days of suspension bridge construction managed with much simpler methods.