Laboratory testing of bogie rotation friction with applied track twisting forces

Laboratory tests of bogie rotation friction using the Centre for Railway Engineering’s heavy test lab facility have been completed for the Rail CRC Project 82 -Bogie Rotation Friction Management. These tests are believed to be the first in the world to rotate a full three piece bogie with track twist loads applied to the wagon-bogie system. The lab testing expands on the simulation studies reported at the last CORE. The objectives of the project 82 laboratory test program were to validate the behaviours of centre bowl friction force occurring during curve transitions as identified in previous simulation studies. The testing included: Centre bearing longitudinal movement in transitions due to track twist loads, or the walking motion of the centre bearing that generates rim contact and adds rim contact rotational resistance [and] Change in the effective radius of friction rotation for the centre bearing due to centre bearing tilt from track twist, and the additional change in the rotational centre when rim contact occurs. Results include the effective centre of rotation and frictional effective radius in the centre bow as altered with pitching force on the bogie. The testing results show that no sliding movement occurs at the CCSB’s until large curving rotations of the bolster occur due to the low elastic stiffness of the CCSB resilient blocks. This has implications for simulation modelling of hunting performance and future CCSB design.