Rail road car and truck therefor

A railroad freight car truck having a load rating, said truck comprising:

• a bolster, sideframes, spring groups and wheelsets;
• said bolster being mounted cross-wise to said sideframes;
• said bolster having respective ends supported on respective ones of said spring groups, said spring groups being carried by said sideframes, said spring groups having vertical spring rates;
• said sideframes being swingingly mounted on said wheelsets;
• said bolster being moveable through a lateral displacement relative to said sideframes, said lateral displacement having an overall magnitude and including a first component associated with a first lateral stiffness, kpendulum, opposing cross-wise swinging deflection of said sideframes and a second component associated with a second lateral stiffness, kspring shear, opposing sideways shear of said spring groups;
• said first lateral stiffness being softer than said second lateral stiffness;
• said bolster being movable in non-trivial yaw relative to said sideframes;
• and
• damper wedges mounted at each end of said bolster, said damper wedges having primary damper wedge angles of at least 35 degrees and having secondary damper wedge angles oriented cross-wise to said primary damper wedge angles.

A railroad freight car truck having:

• a bolster extending cross-wise between a pair of sideframes, said sideframes being swingingly mounted on wheelsets, said sideframes having a pendulum stiffness resistant to lateral swinging deflection thereof;
• said bolster having ends mounted on respective main spring groups carried by said sideframes, said main spring groups each having a lateral shear stiffness;
• said sideframes being yawingly mounted relative to said bolster;
• a four-cornered group of dampers mounted at each end of said bolster, said groups of dampers being biased resiliently to restore said sideframes from a yaw-deflected condition to a squared condition relative to said bolster;
• said pendulum stiffnesses and said lateral shear stiffnesses combining to resist lateral deflection of said bolster relative to said wheelsets;
• said main spring group lateral shear stiffnesses being stiffer than said pendulum stiffnesses;
• and
• said dampers including damper wedges, said damper wedges having both a primary damper wedge angle and a cross-wise oriented secondary damper wedge angle.