High efficiency semi-articulated railway power bogie

In combination in a powered railway bogie:

• a pair of multiple axle sub-bogies having frames individually supporting and pivotable with respect to a span bolster adapted to support a rail vehicle carbody, said sub-bogies being longitudinally disposed in tandem adjacent end to end relation, said bolster and carbody together constituting supported means carried by said sub-bogies,
• power means for driving wheels of the bogie,
• tractive force transfer linkage operatively longitudinally connecting the sub-bogie frames with said supported means, and
• articulating mechanism laterally positively connecting the adjacent ends of the two sub-bogie frames to correlate pivotal turning motions of the sub-bogies relative to the bolster, said articulating mechanism including a preloaded compression element connected between the sub-bogies and being operative to require substantially equal and opposite simultaneous turning motions of the sub-bogies but providing at least limited freedom of relative vertical and longitudinal motions of the adjacent ends of the sub-bogies with respect to one another, such that coordinated turning control with isolation of inter-frame rocking and traction force effects is provided.