Has any line lost its air main as a result of resignalling?

[muzer]

As obviously resignalling removes the trainstops and replaces the interlocking, and I'd have thought they'd maybe use that as an opportunity to replace pneumatic points too? And if so, presumably this required all the P-gates which run off the air main to be replaced at stations?

[Dstock7080]

Trackside air mains are still in existence on sub-surface Lines, pneumatic points are still in existence at some locations:
High Street Kensington
Edgware Road
Aldgate East
Plaistow
Dagenham East etc.

[Tom]

The outdoor sections of the Central line no longer need the air main; I don't know if it's still kept pressurised though.

[ertowerty1]

THe air main serves 2 other purposes apart from containing compressed air:

Longditudial earthing conductor and support for the intermediate cable hangers between cable posts.

On the SSR, the air-main was beeing used as a Longditudial earthing conductor for traction earth faults until the continuous running rail can be implemented throhout.

It seems that projects are reluctant to decommision anything once it has no further use.

There is a general fear that disconnecting anything legacy will shut down something nobody knew still existed and/or still needed and things take considerably longer to reinstate than to remove.

[zbang]

Jul 10, 2023 13:05:34 GMT muzer said:

 And if so, presumably this required all the P-gates which run off the air main to be replaced at stations?

Or to install a small compressed air plant at those stations, probably faster than gate replacement.

Re- invisible legacy systems

I've been involved with projects to do just that, although not on a railway, and it can take an amazing amount of resources. In one project, we had to trace every wire and connection to make sure than nothing was using that system. On a similar tack, a colleague spent three months planning and investigating in order to remove power from a data center for 20 minutes. ("Who owns this old computer stuffed in that rack?" "The label says Rick Smith at x2345. "HR says he retired three years ago.")

[gefw]

Jul 10, 2023 13:05:34 GMT muzer said:

As obviously resignalling removes the trainstops and replaces the interlocking, and I'd have thought they'd maybe use that as an opportunity to replace pneumatic points too? And if so, presumably this required all the P-gates which run off the air main to be replaced at stations? 

The newer style ticket gates are all electric. It is only the original "square/boxy" style gates that use air to drive the paddles (mainly in zone 1)


Quote fixed [goldenarrow]