Has anyone got a list of the class 313 / 508 unit numbers as operated
by London Overground. I covered quite a bit of the NLL and DC Lines
recently and wondered just how many I'd captured on film (or flash
card...).

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

On Jan 18, 12:38*pm, wrote:
Has anyone got a list of the class 313 / 508 unit numbers as operated
by London Overground. I covered quite a bit of the NLL and DC Lines
recently and wondered just how many I'd captured on film (or flash
card...).

Class 313 numbers 101-117, 119-123 and 134
Class 508 numbers 301-303

Andy wrote:
Class 313 numbers 101-117, 119-123 and 134


What happened to 118?

Left Silverlink/Whoever for a career in Directory Enquiries perhaps?

Great Eastern wrote:

Andy wrote:
Class 313 numbers 101-117, 119-123 and 134

What happened to 118?

It's still numbered 018.

--
http://gallery120232.fotopic.net/p9683840.html
(158 832 at London Waterloo, 16 Jul 1999)

On Jan 18, 4:13*pm, Great Eastern wrote:
Andy wrote:
Class 313 numbers 101-117, 119-123 and 134

What happened to 118?

Left Silverlink/Whoever for a career in Directory Enquiries perhaps?

It stayed on the GN lines, I think it was because unit 034 (as 134 was
around 1989-1990) was for a while a two car DC only unit and so was
restricted to the Euston - Watford Junction (and the Croxley Green
branch) line. The PTS being used in the prototype unit for the
networker technology, class 316. The loss of the PTS meant that the
unit was useless for the GN and so it was sent to the LM instead of
018.

Boltar 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?

B2003

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?

B2003

IIRC the 313s are governed to 30mph in DC Mode for Moorgate reasons. I
don't know linespeeds on that section but it may make a difference

On Jan 18, 12:49 am, David Hansen
wrote:

In general a system takes low voltage DC from the supply (the
conductor rail) and inverts it to low voltage AC at variable
frequency, to operate the motors.

Supply 750 V DC - is lifted to higher DC for the HVDC link - VVVF AC
in most case AFAIK.

--
Nick

"Mark B" wrote

IIRC the 313s are governed to 30mph in DC Mode for Moorgate reasons. I
don't know linespeeds on that section but it may make a difference

The FCC units are governed to 30 mph on DC, but the units that were
transferred for the Euston - Watford DC and NLL are not governed in this
way. But it has long been accepted that 313s do work better on AC - it's
just that no-one seems to have published a convincing explanation of why.

Peter

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

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

The problem seems to be with the type of loading that 313s cause on
the DC supplies. In the early 1960s parts of the DC line had a 2 - 2.5
minute headway (back of envelope calculation gives about 2 Bakerloo
trains and 4 6-coach BR/LMS trains taking power) and the substations
coped with that but when cl501s were replaced with 313s they were
unable to run as 6-coach as they tripped out the sub-stations when
moving off.

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

Those date from class 501 (and possibly earlier) days, although not
the original signs. ISTR at least one NLL or DC station has/had
9-coach signs allowing for what was possible rather than what was
"current policy".