Patent ID: 7823513

Claim:
A self-steering railroad car truck having a truck bolster mounted transversely between sideframes, said sideframes having sideframe pedestals mounted upon wheelsets, there being a self-steering apparatus between said sideframes and said wheelsets, said truck bolster having ends, each of said ends of said truck bolster being resiliently mounted to a respective one of said sideframes, said truck having a set of dampers mounted between each said bolster end and its respective sideframe, each set of dampers including at least a first damper and a second damper, the first damper being mounted transversely inboard of the second damper, each damper having a bearing surface mounted to work slidingly against a mating surface at a friction interface in a sliding, substantially stick-slip free relationship when said bolster moves relative to said sideframes, said first damper and said second damper being urged against the mating surface by a first biasing device and a second biasing device respectively, the first biasing device being offset sideways from the second biasing device, said bearing surface of each said damper having a dynamic co-efficient of friction and a static co-efficient of friction when working against said mating surface and said static and dynamic co-efficients of friction of said first damper lie in the range of 0.1 to 0.4.