Re: [VIC] Wooden cars at high speed (was: [VIC] Parallel run)

[dbromage@fang.omni.com.au (David Bromage)]

Stuart Thyer (s.thyer@anatomy.unimelb.edu.au) won a Nobel Prize for literature by writing:
> I still believe the cars would have flexed as new, not as much as now, but
> there has to be give in virtually any structure of its size, even motorbikes
> frames flex, even a skyscraper flexes.

Part of the flexing is caused by torsional (twisting) forces from the auto
couplers. The original frame was only designed to take tension forces
between the screw couplers. 

When autos were added, the inner two tension rods were replaced with
heavier torsion bars. Same with the early W cars. The large W cars were
built with auto couplers in mind, hence the heavier frame. Each BCE
received a single big RSJ-like bar along the centreline, replacing all
four tension rods.

Interestingly, the CWs did not have their frames strengthened when fitted
with auto couplers as it was assumed they would always be at the end of
the train.

Cheers
David