Re: National guage standardisation - why 4'8.5"?

[Bruce Greening <norrail@optusnet.com.au>]

Rjaygee wrote:

> What a load of crap to say 3' 6" is cheaper than standard gauge.  It might
> have been to a certain extent when Qld (and other Colonial gauge states) ran
> dinky little toy trains, but I bet since loads have increased to std gauge
> weights the cost of 3' 6" is probably greater. The greatest disadvantage is
> the horrible wheel flange wear on heavy freight trains on curves.  Some one
> once in this group said that Qld no longer used vertical rail but now canted
> rail. Could someone explain how they could manage to convert as it not only
> involves canting the rails inwards but also involve re-profiling wheels
> treads to a conical profile.  I frankly do not believe they could have
> converted every kilometre of rail or wheel to the canted standard.  I
> understand 90 degree wheel treads and rails cause terrible rail/wheel wear
> with heavy speedy loads. Any comments? Anyhow, to sum up, there is
> absolutely no advantage in using 3' 6".  Too much sun fries brains up in
> Qld.
> Cheers
> Rod Gayford
> "David Bennetts" <davibenn@ozemail.com.au> wrote in message
> z1KC6.2941$EQ3.94176@ozemail.com.au">news:z1KC6.2941$EQ3.94176@ozemail.com.au...
> >
> >
> >
> >
> > With hindsight, I feel it probably would have been better to choose 3'6"
> > gauge. Then you wouldn't have had to worry about as many changes of gauge
> > which were around for so many years when travelling Sydney - Perth.  One
> > hundred years down the track, we're still  running trains which could do
> > everything on 3'6" that they presently do on standard gauge.   3'6" gauge
> is
> > considerably cheaper to build and maintain, if you look at Queensland now
> > they run faster trains on a good 3'6" track than most of NSW, and
> > practically all Victoria and South can do on a wider gauge maintained to
> > mediocre standard.
> >
> > Regards
> >
> > David Bennetts
> >
> >

QR was originally all vertical rail and cylindrical wheels. This was generally
OK until axle loads increased and gauge corner stresses on curves started to
cause major problems. This was corrected initially on the coal and mineral lines
by constructing the new lines (this was about 1980 from memory) with canted rail
and by initially planing the top of the rails to give the same effect as canted
rails on the rest of the heavy haul routes. The wheels were on a mainly captive
fleet and could be machines to the correct profile. Over time all the wheels now
have a conical profile (it is not quite that simple, as wheel profile and the
whole wheel/rail interface is a very complex area). Many of the branch lines
still use vertical rails.

I agree there is little if any advantage in using 3'6" as opposed to wider
gauges, but the conversion costs are very expensive, as most of the Queensland
bridges are not designed for wider gauges. Even on the GNR where the upgrade in
the 60's provided for standard gauge on the bridges, newer bridges have not been
constructed for a wider gauge.

Given the huge cost with little benefit It is unlikely that Qld. will ever
convert.

--
Bruce L. Greening

Norrail@optusnet.com.au
http://members.optusnet.com.au/~norrail