Re: Rail/Road trailers

["comtrain" <comtrain@optusnet.com.au>]

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"Bill" <billguest@the.net.nz> wrote in message
39BA279D.AECDC5C4@the.net.nz">news:39BA279D.AECDC5C4@the.net.nz...
> New Zealand Rail (prior to becoming Tranz Rail) also tried these things.
They
> were successful technically, but I have been told that they were not
really
> economic. The tare was high and the load consequently limited. This may
have
> been a consequence of NZ's road user charges regime, where high axle loads
are
> punished, and the maximum limits are quite low by world standards.
However, rail
> gear is never light........
>
> Bill
>
> Taliesin Walker wrote:
>
> > I heard a mention on the news today about an Australian company that had
> > developed truck trailers that could be used on rail and road. I've seen
this
> > allready done. How common is it and is this practice becoming more
common?
> >
> > Tali

Their is a way around the weight problem, and as far as I know CRT have sole
option on it in Australia.[the following vehicles-not Road Railers]
They are sitting back, biding their time, as to when or if,  they will give
it a go....roughly as follows.
Most semi trailers used in Australia would be able to be coupled into groups
of three at least, just as they are on the road in Road trains!
So without dramatically increasing the all up weight, a train could be made
up of at least 5 trailers and a power unit spliced in behind pushing!
It is envisioned that a self propelled road/rail head end cab, fitted with
Driving compartment and a small engine able to pump up air resevoirs, and
transfer itself between road and rail, would be placed on the track at the
head of a yard, as each road vehicle arrives it is coupled first to the
Driving module, and at least 3 more would be attached behind. A propulsion
module would then be coupled behind. This would consist of a loco contol
equiped , unit with at least one axle hung traction motor, Suitable prime
mover,compressor and an air resevoir. Behind this another 4 trucks, another
propulsion module, etc etc!
The length of the train is not a problem, the trucks are supported on braked
bogies, exactly as now, except that every 4th one is a power bogie.
Electrically applied and released pnuematic disk brakes would be almost
instantaneous. Power cables would  not be needed, exactly as Broken Hill is
doing on their 240 car ore trains in the west.
The cost of the equipment would be very low[compared to a complete
locomotive], and advantages, such as changing out faulty Driving units or
propulsion units, rather than the whole Locomotive.
Disadvantages would be that the equipment would be limited in its
application,  and to remain cost effective would need to be fully utulised
in both directions.
Modifications to the trucks would need to be made to hook the air through
them, and of course hook the trucks together.
In the US tractor Trailers generally have only two axles on the trailer. In
Australia we would need to overcome the problem of limited space due to the
third axle.
Road raliers , of course, have movable tri-axles and the airbag suspension
is utilised to retract the tyres safely above the rails.This may need to be
avoided to keep weight and costs down.
I believe all problems have been overcome, apart from the assurances that
Industry will embrace long haul by Rail.
Rod [comtrain]