what are miter rails?

Tommy posted:

I read the term "alignment of miter rails" as a factor.in derailments. Exactly what are miter rails?

Try Google for "Railroad Miter Rails".

Apparently these are for rail alignment on movable bridges. Do they have any other applications?

Thanks.

I believe some car floats and ferries also have them.

Coincidentally I was watching a video this weekend about the rebuilding of the Grosvenor Bridge in London several decades ago and it talked about mitered rails.  I think, in addition to allowing flex/movement in the bridge when carrying a load, it also mitigated rail thermal expansion across its length.

 Tommy

I looked through some of my pictures and following Hot waters google there is a picture of the Cape Cod bridge that has them. Same as picture posted above. That would be for lift bridge part. to me it would also allow for expansion and contraction. Wheel batter is important part of it, with out the "rider" the track would be battered in time. Cold weather the gap would be huge and the rail would get destroyed in no time. The rider will hold the wheel up and roll over the gap without dropping.  if misaligned/ missing, the hammering would break something over time and you would have your derailment. The first close up just behind the speeder wheel is the Miter Track.

just down from the rider rail was a second segment that almost looks like a spring frog, but is two rails tightly fit with the bridge segment bent outwards but sprung tight. That to me absorbs the flexing of the bridge as the train passes. Cape Cod has them and a large bridge on the WLE, at Mingo junction also has them. 

 Jamie