Sunset route
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- 27 Oct 2015
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Are Closing up signals what would be called draw ups on the Underground, in any case can you please explain what they are for those of us unaware. Cheers.
Draw ups on the underground are speed controlled signals which will not clear until the train is doing less than a specified speed, they ensure that the train does not reach the signal ahead travelling quickly enough to do damage if it spads that signal.
The ones at East Croydon work with an automatic restrictive aspect from red once the berth track circuit has been occupied for a pre-determined time.
Some term lifters straight from Railway Group Standards.
Closing-Up Signal
A Signal that is provided to optimise Headways and/or to provide earlier clearance of junctions on the Approach To stations. It may or may not form part of the normal Aspect Sequence.
Overlap (OL)
The distance beyond a Stop Signal that must be clear, and where necessary Locked, before the Stop Signal preceding the Stop Signal in question can display a Proceed Aspect.
Reduced Overlap
An Overlap that is shorter than the minimum permitted length of a Full Overlap, where the permitted approach speed is below a specified level which still allows an unrestricted approach to a Signal at danger.
Restricted Overlap (ROL)
An Overlap that is shorter than the minimum permitted length of a Full Overlap, which is available only when the preceding Signal is subject to Approach Control by selection of a Warning Class Route.
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