"D7666" wrote

There is a substantial uplift in heating effect from the new trains.
Unless my sums are seriously flawed, there'd have to be some seriously
hefty cooling gear to cool stations. Gear that itself draws power ...
maybe more than the entire train regenerated power is taken up by air-
con ?

Add to that the congestion relief works at Victoria and the more frequent
service, there'll be more passengers pumping kilowatts into the system.

Perhaps the Victoria Line needs to be extended into the open air, at least
so the piston effect of trains can add ventilation into the tunnels, and
ideally so that the next generation (49 stock) can have aircon that takes
heat out of the system and dumps it in the open air. Take over Chingford
from National Rail? Quadruple Northumberland Park to Cheshunt, with a
extended Victoria Line running the local service?

Peter