On Thu, 14 Feb 2008 20:40 +0000 (GMT Standard Time), Colin Rosenstiel
wrote:

I can't remember what kind is at Gunnersbury etc, but on the
Bakerloo shared sections, I think the markers are NR style.

For both the Underground and Overground, right?

The Overground has "3 car stop" and "6 car stop" signs (or "S car
stop" at some stations instead),

I thought the "S car stop" was what they used for both on the
District, though I could be wrong.

though 6 car trains never run (and it
may not even be possible).

Why would it not be possible?

The power supply may not be able to cope with the current drawn by a
6-car 313 accelerating.

How do they cope with 6-car 313 trains on the GN then?

The power supply on the GN can cope with them. The power supply on the
DC lines can't (according to a recent thread).