London Banter - View Single Post

Colin Rosenstiel · September 18th 08, 10:04 AM posted to uk.transport.london

In article
,
(Andy) wrote:

On Sep 17, 4:34*pm, (Colin Rosenstiel) wrote:
In article
,
(somersetchris) wrote:

The reason why the trains switch to AC is because trains using the
DC stretch along there would have to go at half power.

Isn't that just a general feature of the 313s? As built for the GN
they ran in series only on DC because the Northern City Line section
is limited to 30 MPH anyway. It doesn't affect the 508s and I thought

the 313s transferred to the NLL/Euston Watford Service were modified.

Yes, I think this is the case. The Northern City trains are limited to
30 mph in the tunnels anyway. I don't think that there is any
difference in the power available under DC or AC. If there was any DC
speed limiters on the original units, they have certainly been removed
from the NLL units.

I don't think there was anything to "remove". The DC controls were
series-only. They would have had to be modified for full series-parallel
control, something not quite so simple.

--
Colin Rosenstiel