Dan_Bower%RPI-MTS.Mailnet@MIT-MULTICS.ARPA (09/24/85)
The whole idea of rail anchors is to restrain thermal expansion. When rail temperature changes, a force of expansion or contraction exists, i.e., it *wants* to expand or contract. That doesn't mean that you have to let it. If the holding force of the rail fastenings exceeds that of expansion or contraction, the rail stays put.