"Boltar" yahoo.co.uk> wrote:

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

No time to check, but I believe the NLL timetable is more intensive than
when that section was first used by the 2-EPBs.

Chris

* So says Mr Rob Curling on Video 125's 'North London Line Drivers Eye
View'.

On Thu, 17 Jan 2008 22:22:08 -0000, "Chris Read"
btinternet.com> wrote:

< various snipped out >

I don't know what the current limit relays were set at on 501s but
being 4 motors per unit would be likely to draw more than a two motor
2EPB.

Published ''spotting book'' values of a 2EPB are 2x250 hp and 501
4x185 hp so that makes a 501 in round figures 50%% more powerful than a
2EPB - but I'd caution those numbers with similar comments I have made
before about DC EMU in that the current limit relay setting needs to
be known to understand peak current draw.

As regards another part of the thread, I thought 2x313 operation was
killed by platform length limits. 501 units were on 57 foot frames
and platforms that could take 6cars laid out for that length - but
could not take standard 6car sliding door trains with 20 m bodies.

And I can't see why a 6car 313 would draw siginficantly more power
than a 6car 501 to trip traction supplies. Again using ''spotting
book'' values, without current limit values, a 313 has 8x82 kW motors
that in round figures is 880 hp per unit - while a 501 is 740 hp.

On Thu, 17 Jan 2008 23:13:08 +0000, Charles Ellson wrote:

Interesting, especially considering the line is fitted with (IIRC
Silverlink-style) "6 car stop" signs.

Does anyone know how many, if any. of the original LNWR sub-stations
are still in use? There are various large buildings adjacent to the
NLL/Euston DC Lines which seem to foor the bill but others have
disappeared. The one visible on the NLL from the Met/Jubilee Lines has
gone, as has another large structure which stood near East Putney on
the EN side. Is the large building on the WCML side in the Kenton/
Northwick Park area a former LNWR sub?

On 17 Jan, 22:22, "Chris Read" btinternet.com> wrote:

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

On Fri, 18 Jan 2008 06:57:48 +0000, asdf
wrote:

On Thu, 17 Jan 2008 15:44:51 -0800 (PST), D7666 hotmail.com>
wrote:

On Jan 18, 4:04 pm, Charles Ellson ellson.demon.co.uk> wrote:

AFAIK 313s (and 507/508) are simple camshaft operated resistance
control systems (although there my be some electronic supervision)
little different than anything built from 1930s onwards. If 313s have
a bigger peak current then that will be down to current limit relay
settings. Apat from knowing what that value is, I can't see why they'd
be more peaky than a 501.

On Fri, 18 Jan 2008 04:19:29 -0800 (PST), bowroaduk@yahoo.com wrote:

Eh? This sounds like the LSWR, not LNWR!

Yes. AFAIK it is the only one still in use,; all the rest were taken
out of use in the 1940s, new rectifiers etc. being installed in
smaller buildings nearby. The buildings survive at Willesdan
Junction (derelict and rail-locked), South Acton and Headstone Lane
(both heavily adapted for other uses.) Dunno about Dalston
Junction.

There is a similar looking building at Harrow and W but this was not a
railway one.