On 17 Jan, 22:22, "Chris Read" wrote:
"Boltar" wrote:
Why do the trains on the NLL switch over to 25Kv AC at Hackney Wick
and then switch back to DC at Dalston when the 3rd rail is continuous
along that section anyway? Why not just stay on DC and save the wear
and tear on the pantograph?

Because the DC supply in that area is somewhat constrained, and only allows
a limited number of simultaneous train movements.*

But unless there are other DC trains using that section other than the
NLL , it seems theres no DC activity on it at all at the moment. If
the above is true why not limit the use by trains using AC in one
direction but DC in the other?

B2003