Saturday 13th/Sunday 14th September part closure

[sawb]

Just seen on the TfL website that the Northern line is to be closed on 13th/14th September between Charing Cross/Moorgate and Hampstead/High Barnet/Mill Hill East.

What work is being undertaken?

Where will be the service frequency, and where will trains reverse? I didn't think there was a crossover at Moorgate on the Northern line any more.

[superteacher]

The crossover at Moorgate is still there - a trailing crossover north of the station.

[Deleted]

Aug 4, 2014 8:11:10 GMT superteacher said:

The crossover at Moorgate is still there - a trailing crossover north of the station.

Yup. I believe a scissors crossover that was once there has now been removed though - although that could've been gone for years and year, I couldn't tell you!

[superteacher]

The scissors crossover was south of the station and was there when the lne opened as far as Moorgate. It was, as has been said, removed many years ago, possibly when the line was extended north towards Angel and Euston.

[Dstock7080]

Aug 4, 2014 7:43:29 GMT sawb said:

What work is being undertaken?

Points and crossing work at Camden Town, track renewal at High Barnet.

[CSLR]

Aug 4, 2014 10:55:20 GMT superteacher said:

The scissors crossover was south of the station and was there when the lne opened as far as Moorgate. It was, as has been said, removed many years ago, possibly when the line was extended north towards Angel and Euston.

That is the case. The scissors crossover was commissioned in 1900 when the first part of the northern extension was opened and Moorgate Street became the temporary terminus. After it became a through station, the configuration was changed to trailing points.

The scissors crossover was re-installed in 1922 when the station once more became the northern terminus during the reconstruction. It was removed again after the line stopped carrying passenger traffic at the end of 1923.

[Tubeboy]

Yep, trains can reverse at both Charing Cross and Moorgate. Great to see you back CSLR.

[Deleted]

What's the difference between a scissor and a trailing crossover, is a scissor one when the two crossing tracks cross each other (like north of Brixton) and a trailing on is where one crossing track come after the other one?

[Deleted]

You are right about the meaning of 'scissors crossover' - so-called because they look a bit like a pair of open scissors. They also look like an X, or rather, more like this: |X|. I never was too sure about a trailing crossover, but I think the idea is that a crossover is facing if the moving blades face the normal direction of travel and trailing if they don't. So a trailing crossover is always used wrong-road, if you see what I mean, you always have to change ends, you have to go over it backwards. An example of a facing crossover would, I think, be the one between East Acton and North Acton, connecting platforms 1 & 2. This faces the normal direction of travel. Queensway would be another example I think. Compare this to the one between Liverpool Street and Bank (or between Liverpool Street and Moorgate on the SSL for that matter).

Edit: If I've understood correctly: Assuming left hand running:

Trailing: |\|
Facing: |/|

[Chris M]

Correct.

To put it perhaps a bit more simply, facing crossovers (and facing points in general) can be used by trains travelling in the normal direction of travel. Trailing crossovers (and trailing points more generally) can only be used after a train travelling in the normal direction of travel has travelled beyond the points and reversed.

There is a moderately good Wikipedia article on the subject, with a diagram, at en.wikipedia.org/wiki/Facing_and_trailing

[norbitonflyer]

Assuming the parallel tracks connected by the crossover run in opposite directions, on a trailing crossover you have to reverse before you can use it, whilst on a facing crossover you have to reverse after you use it. In the Victorian era, because of the inherent possibility of taking the wrong road at speed, facing crossovers were avoided on main lines wherever possible.