Harry, The crosshead forces would cause an up-and-down force at the front (mostly up). The fore-and-aft would be in some connection with the elasticity of the train and couplers. Then there was the left-right nosing. And the rolling motion (The UK "Rivers" were bad at that one).
Clearly the steam loco was basically unsound (8-) Would never be allowed today !!! Peter Harry Wade wrote: > > At 08:58 AM 12/22/01 -0800, you wrote: > >I wonder if the lift to the loco front end was visible ? > >Peter Trounce. > > Over they years I've run across a number of descriptions of US > locomotives (and a few British) which mention they rode with a pronounced > for and aft rocking motion at certain speeds, posed as one of their lovable > (or bothersome) idiosynchrasies. Perhaps on some of them this was induced > to some extent by the alternating force on the guides finding the natural > frequency of the mechanism, like an automobile wheel and tire that only > wobbles at a certain speed? > > Cheers, > Harry
