Re: Trains, Road Trains and a little bit of info.

["andrei" <andrei@ausisp.com>]

< Tell > <telljb@netozemail.com.au> wrote in message
660cjs0k1o000rnjri4np4tnmdu9ibbc32@4ax.com">news:660cjs0k1o000rnjri4np4tnmdu9ibbc32@4ax.com...
> B-Doubles, yes most folks have seen them.
>
> Triple road trains.!  ....well I suspect most folks
> down south and along the east coast have never seen one
> of these in the flesh.
>
> Quad trains.  Yoiks.!  Yep that's my word for them.
> This is a prime mover with a tri-axle trailer, behind
> that another tri-axle trailer AND behind that a
> B-Double, just follow the ASCII below.
>
> 0===00=====000----00=====000----00====000====000

Nothing to do with railways, but I think what you're talking about is called
an A-A-B quad road train.

A-Train descibes a combination containing the trailer to trailing dolly
connection via a Ringfeder to drawbar. (The drawbar can be a single pole or
of an A form(looking from above)).
B-Double - pretty obvious.

Thus
_/-| [-------]    [--------]    [----] [-------]
0===00=====000----00=====000----00====000====000
               A             A        B
Some of the more adventurous operators have specced tri-drive prive movers
and tri-axle dollys. The combinations therefore have all axle groups as
tri-axles except for the steer axle.  If your example above were to have all
axle groups apart from the steer as tri's the combination would gross
6.7t(extra 0.7tonnes on steer axle for road train spec prime mover) +
7(22.5tonnes) = 164.2tonnes
or 6.7t + 7(20tonnes) = 146.7tonnes depending on the roads they were
operating on.
Exactly as you described would be 6.7 + 17 + 22.5 + 17 + 22.5 + 17 + 22.5 +
22.5 = 147.7 tonnes
or replace the 17's with 16.5 and 22.5 with 20 for a total of 136.2 tonnes.