It seems my memory wasn't quite as reliable as I thought. It should read 170°C, not 200°C. Foot in mouth!

And there are some exotic alloys used too. In addition is seems they do use this for new construction too. [Linked Image] The article below provides a good overview.
http://tdworld.com/ar/power_transmission_line_conductor/index.htm

[This message has been edited by C-H (edited 02-29-2004).]