Rail road car and truck therefor

A rail road car truck having

• 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 carried by said sideframes, each of said spring groups including an array of coil springs;
• 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 cross-wise swinging deflection of said sideframes and a second component associated with sideways shear of said spring groups, said first component being larger than said second component, said overall magnitude being greater than each of said first and second components;
• and
• said lateral displacement being constrained within a non-trivial range of lateral travel by interaction of members of said bolster with members of said sideframes;
• and
• said range of lateral travel is at least ¾ inches to either side of a neutral position.

A rail road car truck having

• a bolster, sideframes, spring groups and wheelsets;
• said bolster being mounted cross-wise to said sideframes;
• said bolster having respective first and second ends supported on respective ones of said spring groups carried by said sideframes, each of said spring groups including an array of coil springs;
• 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 yaw relative to said sideframes;
• said truck having yaw resisting members mounted yieldingly to oppose yawing of said bolster relative to said sideframes;
• and
• said lateral displacement magnitude being limited by members of said truck to a range that has an amplitude of at least ¾ inches.

A rail road 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 carried by said sideframes, each of said spring groups including an array of coil springs;
• 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;
• said truck having yaw resisting members mounted yieldingly to oppose yawing of said bolster relative to said sideframes;
• and
• when laded to said load rating, said truck has a natural frequency in vertical bounce mode that is less than 2 Hz.

A rail road car truck having:

• a truck bolster extending cross-wise between a pair of first and second sideframes, said bolster having first and second ends seated on first and second spring groups carried in said first and second sideframes respectively, said sideframes being capable of yawing relative to said bolster, and said spring groups each including an array of coil springs;
• a load rating;
• a lateral spring stiffness and a lateral sideframe swinging stiffness;
• members mounted yieldingly to resist parallelogram deformation of said truck;
• and
• when loaded to said load rating, said lateral sideframe swinging stiffness being softer than said lateral spring stiffness, and said truck bolster having a range of lateral travel relative to said sideframes, said range of lateral travel being greater than ¾ inches to either side.