Charing Cross crossover geometry

But is the rest of the geometry still such that the physically straight route through the scissors crossover is actually through the diamond crossing, with the signalled straight route being curved slightly?

I find it interesting that both routes through the crossover from the s/b line have arbour lights - which way do the lights point for the route to what would have been the s/b platform, had the line been extended? (I forget which platform is numbered which).

Thanks!

Does the home signal into the crossover have a full overlap into the crossover, or is it a partial overlap? You did say that the crossover was restricted to 25mph but not why; is it because of lack of use or because the signalling dictates it?

H123 has a similar arrangement with route lights for both platforms (coming from Hatton Cross).

I remember the geometry of the crossover there to be similar to that at Moorgate, with the nominally straight route cuved and the turnout straight.

That was my next question! Given the time period in which it was built I'm not surprised it was initially equipped with moveable angles.

But that same technology isn't yet (to my knowledge) in use on LU metals yet, unless it was installed during the Watford South Junction works...

I'm sure that moveable angles are still in use in the Harrow on the Hill area?

Given the length of the overrun, I'm surprised that a 25mph speed limit is imposed. Is the speed limit inbound only?

The overrun isn't that long - both overrun tunnels accommodate sidings, and whilst the sidings finish just beyond Southampton Street, the empty tunnels continue as far as Lancaster Place.

At Walthamstow Central, the approach was designed that if the siding was unoccupied, a full-speed approach would be provided. In the event that the siding was occupied by a train, the approach would be restricted to 22mph... until recently when the condition of the crossover was allowed to deteriorate so that all trains are now limited to 22mph.

Maybe a more elaborate arrangement was not installed at Charing Cross because it was only intended as a temporary terminus?

It's not the only example. Since PPP, many previously high-speed points have now had speed restrictions applied. There are numerous examples on the Metropolitan Line, for example Harrow North Junction.

I leave you to infer your own conclusion.

and yet it had operated safely at greater than design speed for ~30 years prior to PPP

I think it was an M63 machine used for 10A at H123 in the end. I've got the circuits for it somewhere...