Re: 40 class bogies

Chris Stratton (stratton.chris.cp@bhp.com.au)
8 Oct 1997 04:18:52 GMT

Allan Brown <ajbrown@ozemail.com.au> wrote in article
<343B04B5.17D3@ozemail.com.au>...
> It is written that the NSWGR 40 class diesel electrics were a derivative
> of the American RSD4/5 units, but suitably altered for local conditions.
> Considering that the RSD4/5s had asymmetric bogies with all axles
> driving, what prompted the change resulting in the 40 class having
> equdistant A-1-A bogies? Why wasn't a Bo-Bo arrangement used?
>
> Allan Brown
>
>
One advantage of the A1A-A1A over the Bo-Bo is the lower axle loading as
there is six axles instead of four. I don't know if that is the reason it
was used but it caused problems later with wheelslip caused by the driving
wheels wearing faster than the non-driving wheels. This then allowed one
driving axle to lift the wheels off the rails as the centre wheels were
larger which created a see-saw effect pivoting on the centre axle. That is
the reason the centre axle was removed from the units that went to Robe
River, as the higher axle loading on four axles was no problem.
Regards,
-- 
Chris Stratton
stratton.chris.cp@bhp.com.au   


Any opinions are all my own work.