Joined
·
746 Posts
If I may, let me present a little science/math demonstration. In Ken's RGS Southern above, the track that buckled needed to be gapped as follows with the following known information.
Known:
Coefficient of expansion of aluminum rail = .0000123 inches per inch of length per degree of temperature rise.
Length of track needed to compensate for expansion
total temperature range
So.....
If Ken's striaght line track is 10'-0" long (120 inches), and say the total temperature variation is from say 20 degrees for a low and 100 degrees for a high for a total temperature variation of 80 degrees. Hence, 80 degrees times 120 inches times .0000123 equals 0.11808 inches expansion.
These numbers do not consider rail mounting (tight/loose/fixed) or roadbed (floating in ballast/attached to stringers/etc). And yes, the prototype railroads have the same expansion/contraction issues. I am familiar with Ken's section of the country, I was raised in NE Jersey. I spent many days and nights railfanning Pensy, and later Conrail.
Hope this is enlightening to some.
Bob Cope
Known:
Coefficient of expansion of aluminum rail = .0000123 inches per inch of length per degree of temperature rise.
Length of track needed to compensate for expansion
total temperature range
So.....
If Ken's striaght line track is 10'-0" long (120 inches), and say the total temperature variation is from say 20 degrees for a low and 100 degrees for a high for a total temperature variation of 80 degrees. Hence, 80 degrees times 120 inches times .0000123 equals 0.11808 inches expansion.
These numbers do not consider rail mounting (tight/loose/fixed) or roadbed (floating in ballast/attached to stringers/etc). And yes, the prototype railroads have the same expansion/contraction issues. I am familiar with Ken's section of the country, I was raised in NE Jersey. I spent many days and nights railfanning Pensy, and later Conrail.
Hope this is enlightening to some.
Bob Cope
