Re: 40 class bogies
Peter Knife (pijik@nor.com.au)
Tue, 21 Oct 1997 18:52:12 -0700
Allan Brown wrote:
>
> John McCallum wrote:
> >
> > In article <626r35$31e$1@lios.apana.org.au>, craigd@lios.apana.org.au (C.
> > Dewick) wrote:
> >
> > >They also did it so they'd never have to worry about the problem of wheels
> > >on the two driven axles slowly becoming smaller in diameter than the two
> > >undriven axles. Remember that the if the driven axles slipped, the undriven
> > >one wouldn't, so it's wheels would be slightly larger in diameter after some
> > >time in service.
> >
> > I do not believe that the difference in diameter between the driven and
> > undriven wheels would be a problem in service. It must be remembered that the
> > 40 class, together with the later 43, 44, 45 and 48 classes, had equalized
> > bogies.
> > In this type of bogie, the weight of the locomotive is distributed between the
> > axles by means of beams resting on the axle boxes. The weight on each axle
> > does not alter because of rough track or uneven wheel wear. This is not case
> > on 42, 421, 422, 442 and later designs, which were not equalized, and uneven
> > wear would cause uneven weight distribution.
> >
> > John McCallum
>
> So far you guys seem to have overlooked the basis of my original
> question: why equidistant bogies as against the RSD4/5's standard
> asymmetric ones? I have since found out the reason. I am still waiting
> for one of you guys to hit on it. Come on; don't let me down.
>
> Allan
It's simple. The RSD series had all axles powered, and the centre axle
was offset to allow for the additional traction motor. The 40 class was
A1A-A1A and hence there was no need to offset the idler axle (which was
only there to reduce the axle load.
Cheers
Peter