Trucks

[Anonymous]

How are engine and rail car trucks attached to the under frames? Thanks.

[Anonymous]

They use a huge wood-screw, tighten it up, then back off about a quarter turn to allow swivel. No, not really. Freight cars rest on the trucks with only their weight and a centering pin resting in a counterbore/boss arrangement to hold things in place. Derailed cars are often separated from their trucks; many newer cars have the car number stenciled on the truck frame to keep the trucks on the right car. I don't know about locos, but I expect they are similar.

[oltmannd]

The centerpin and mating bowl on the truck bolster are much more substantial on locomotives because most have to transmit the tractive force from the rail thru to the coupler. In general, they are larger in diameter and deeper. Loco trucks have "keepers" so that if you lift the loco, you lift the trucks. To remove the trucks, you have to unbolt the keepers.

[edblysard]

Next time your up close to a SD 40, or Ge's Dash 9s, look for the limiting chains that keep the truck with the locomotive. They are about 12" long, on all 4 courners of the trucks, just inside the frame lip.
Ed