London Banter - View Single Post - 5 car Overground trains to Watford Junction

[email protected] · December 22nd 14, 02:13 PM posted to uk.transport.london

On 22.12.14 15:03, Recliner wrote:
wrote:
In article , d
() wrote:

On Mon, 22 Dec 2014 06:14:01 -0600
wrote:
In article

-september.
, (Recliner) wrote:

Mizter T wrote:
On 21/12/2014 21:49, wrote:
I read in a magazine that Overground trains on the Euston-Watford
service won't be able to be extended to 5 cars until power supply
upgrades have taken place. I don't understand why power supply
upgrades are is needed. This route used to be served by 7 car
Bakerloo Line trains.

Guessing but perhaps "used to" are the operative words in that
sentence, i.e. the power supply kit / arrangements on the line have
changed since 1982.

And maybe 5-car 378s, with modern traction equipment, need more power
than old tube trains (1972 stock, presumably)?

1938 stock actually. I guessed it's the same as the Southern. Massive
power supply upgrades were needed for the switch from camshaft-controlled
stock to power electronics.

You have to wonder why it was necessary if the claims about
electronic control being more efficient are true. Surely that
couldn't have been marketing fluff
could it?

I now recall reading about it at the time. The characteristics are different
and break old supplies. The efficiency mainly comes from regeneration of
course.

I think my question was really because I didn't realise the new 5th cars
were powered.

I think the new traction packages draw a much heavier current during the
initial acceleration phase. It was one of the urgent projects the SRA had
to deal with when the new 'lardbutt' Siemens Desiro trains were introduced
by SWT. I seem to remember Roger Ford writing about in MR at the time. The
old traction supplies might also need beefing up to cope with regeneration
as well.

Forgive me, please, if I asked this question earlier, but what's the
deal at this point with re-extending the Bakerloo Line out to Watford
Junction? Or is that dead with the emphasis now on extending further
south from Elephant & Castle?

IIRC, one of the reasons that LUL service has not developed much south
of the river is because that part of town is largely on sand.