Bogie of wagon C(64T)-4917203.

Notice that the bogie is cross braced to help prevent the bogie from going out of parallel.

If the bogie goes out of parallel then the axle centerlines may no longer be perpendicular with the rail.

This situation would then lead to the bogie hunting for an effective track center that could not be achieved.

The wheel set of a hunting bogie could actually gain sufficient side force, as determined by loading and velocity (and wheel and rail head geometry), to climb up the rail head and break out of the gauge (a derailment).

As the Chinese National Railways is increasing the over the road speeds of all trains, the cross braced bogies (and other designs) are to become the norm.

B.W. Ring, 2002-March-23, Guangzhou, Guangdong, China.

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