Paul Scott wrote:

"Boltar" wrote...
I've been wondering , how does carrying around another 25 tons of dead
weight (I believe the new 7th cars are all unpowered) affect
performance
of the trains?

B2003


From December's Modern Rail, which has about 3 pages on the modifications,
'Traction capability has been increased marginally to compensate for its
greater mass.' The train sets were originally designed to allow for a
seventh car, therefore the auxiliariy equipments on the six car set were
sized to allow for the seventh, which is actually carrying ballast in lieu.
The article goes on to explain further that the trains are capable of much
greater performance, but full exploitation of speed, acceleration and
retardation improvements will require new communications based train
control(signalling) when the line is upgraded.

What is the point of tube trains carrying ballast?

--
Aidan Stanger
http://www.bettercrossrail.co.uk