dpb wrote:
On 08/13/2014 11:55 AM, rangerssuck wrote:
...

Ed, in practice there'd be expansion joints or someone looking for a
job. It would also probably make a hell of a noise.

The new continuous rail rely simply on sufficient hold-down force to
restrain it -- I was wondering not terribly long ago as was watching
Union Pacific replacing a bunch of the main line thru here as were
having not uncommon KS summer days of 105F or on occasion quite a bit
higher than that...so I looked up and as far as I could find that's the
way it's done. No magic low-expansion alloys, or other tricks I could
find...

I was told that the new long rails that are used these days are installed
under tension with some sort of winch like device to counteract expansion
in hot weather.