On Wed, 16 Jul 2008 22:57:08 +0100, Paul Scott wrote:


Providing enough battery to allow a set to limp to the next platform
might be some what useful and not that expensive in the grand scheme of
things.

But as we have already discussed, it flys completely in the face of the
DfT's light weight requirements...

But how much would it really add to the total weight ?. The trains will
be carrying batteries anyway - and those batteries will be expected to
not only run emergency lights and some basic 'control' circuits, but also
emergency ventilation fans and an air-compressor so that the pantograph/
shoe gear can be operated, (and possibly also to release spring activated
parking brakes). The trains will like wise also have all the battery
charging and monitoring gear anyway. Changing the traction system to
accept input from the battery bank wouldn't add much - another set of
contactors.

So really how much EXTRA battery capacity would be needed to 'limp' the
set to the next platform in the tunnel sections ?. And also remember the
traction converters are distributed - so say an extra 2 batteries and a
DC contactor in each motor car ?, and we don't want line speed here, only
enough power to overcome friction and the weight of the train on a grade
so that it will actually move.

Yes it adds weight, but not much, and it sounds to me a great idea for
being able to assist with moving trains to places were evacuation is much
easier.

Could also be handy in depots to get trains into inspection roads with
out having to go through the whole procedure of clearing the area and
energising the conductor rail/overhead and then locking it all out again
before work can start.