Re: Bracks supports VHST to Melbourne

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

Dave Proctor (daproc@spambait.ozemail.com.au) wrote:
> "David Bromage" <dbromage@fang.omni.com.au> wrote in message
> 1_Ba5.161$Ra3.681103@news0.optus.net.au">news:1_Ba5.161$Ra3.681103@news0.optus.net.au...
> > James C. (james_ccj@my-deja.com) wrote:
> > > TGV tracks (LGV) can take normal freight trains as well, SNCF let
> > > freight trains run over its Altanitc line since 3 years ago.
> >
> > Provided they maintain the 17t axle load limit.

> Isn't this the axle load for hish speed trains, and designed to minimise
> track forces produced at high speed?  Wouldn't a train travelling at a much
> lower speed produce less track forces and thus allow higher weights?

Yes and no. I think the freights can operate at half the line speed (about
140km/h on the PSE line) with 19t axle load.

> Also, wouldn't it be possible to engineer the line from the construction
> phase to allow for higher axle loads?

Yes, but it puts the costs through the roof. Germany found that out to its
peril in the mid-80s when the first ICE line was built. You get minimal
additional benefit for massively increased capital cost.

In the end, they found it better to get more passengers onto the high
speed lines and free up the existing lines for slower (less than 160km/h)
passenger trains and faster freights.

Cheers
David