5 ms·This of course beeing the effect of seemlessly welded together rail with nowhere to go..by warumdarum 2mo agoThis of course beeing the effect of seemlessly welded together rail with nowhere to go..jimnotgym 2mo agoIndeed. Didn't they used to have expansion gaps?cgyvbunji 2mo agoThey did. It's what caused the click-clack sound trains used to have, and the change to continuous welded rail is why there is no click-clack anymore.