Doesn't make sense to me. How can it run away when placed on the
track? Was it in gear and if so
didn't anyone notice any of the wheels turning? If it was purely by
gravity what sort of gradiant is on
that stretch of line that it moved off so fast someone couldnt' jump
into the cab?

"The operator of the machine jumped from it at Gidea Park"

Why didn't he put the brakes on?? Presumably they were working or it
wouldn't have been able to drive there
by road in the first place.


what can happen with some machines, where the rail wheels are unpowered and
are driven by the rubbers, is that if the operator, whilst on-tracking the
machine does not put one rail axle all the way down before the other you can
end up with a situation where neither rail wheel is in contact with a rubber
tyre and the machine will start to run away.

if the machine controller is sensible he will chuckle to himself and wait 1
second for the operator to drop one end and stop the machine, but, if he is
a ****wit he will panic, hit the emergency stop button and leave the
operator rolling off down track in a machine with no way of stopping it.

i have only seen this myself on my machine controllers course where the
instructor did it on a short piece of track to show us what not to do but i
do know of worksites where it has happened for real.

since the report mentions a MEWP (mobile elevating working platform) it was
probably one of these http://www.readypower.co.uk/products/32, i have MC'd
these myself in worksites in this area, usually for balfour beatty OHL.

this method of driving a road rail vehicle (RRV) is called high rail, the
other 2 are low rail where the rubber road tyres sit on the rail and small
rail wheels are used only for guidance (ie land rovers) and independent
drive where separate (usually hydraulic) bogies are used, these are usually
used on tracked vehicles (ie dozers)

james