Re: Rail/Road trailers

[matthew@mail.usyd.edu.au (Matthew Geier)]

In article <Pjzu5.47879$c5.131666@newsfeeds.bigpond.com>,
Ronald BESDANSKY <ronbest@bigpond.com> wrote:
>I think they roll rail bogies under the trailer, which lift the road wheels
>clear of the track. The bogies can be hauled "light" and each one carries a
>road number. Must be odd to see a train of just bogies trundling past!
>
>The trailer would have to be designed for railway impact loading, which no
>doubt increases its cost and tare somewhat.

 The tare is one reason why the trailers are not all that popular. The heavier
the trailer, the less paying loading, and in the competitive road frieght
industry every little bit counts.

 I remember reading some time ago about the Wabash RoadRailer IV how they
had worked very hard to lower the tare weight, but it was still suffciently
higher than a normal trailer to cause considerable resistance by the road
hauliers. This is one reason why the road-railers have special intergral
braked bogies, so the road trailer isn't carrying any 'railway only' excess
bagage when on the road.

 Same situation with the road-trains. You don't often see a trailer with
a hitch enabling it to tow a trailer around Sydney. If they can't
road train it, they use a lighter trailer, thus pack more paying load
in for the axle load....