How often is 3rd rail replaced?

[M7R]

While waiting at New Milton today for the 442 return I noticed that the 3rd had seen better days, with the web corroded away for over 3 sleepers worth and a pot missing too where it will in a poor state, this got me thinking how is the 3rd rail inspected? Track patrols only or does the NMT also inspect it via a camera? Also how often is it replaced? As I have seen the delays and chaos that can happen via threads on here when collector shoes get removed via the 3rd rail defects, so I was suprised to see this section of rail in such poor state (there was other bits where the web was already starting to hole, and the base of the rail was also missing in places as well).

 

[cjmillsnun]

Report it then.
http://www.networkrail.co.uk/aspx/1346.aspx

 

[Trog]

There was still LNWR marked third rail in the Euston - Watford DC lines up until a couple of years ago, may still be some of it there. That was 105lb when new the current standard is 150lb. I have heard that a rule of thumb for conductor rail is to expect it to wear down by 1/64" per year.

 

[Peter Mugridge]

A bit of 3rd rail in a similar state to that shown in the OP was left in place for about three years in Epsom platform 4 until finally replaced a couple of years ago.

I do sometimes wonder just how badly corroded the 3rd rail has to be before it collapses.

 

[M7R]

I wouldn't have thought that the collector shoes are pushing down with tons of force, but it must be a few kg worth in order to maintain contact while in motion due to the suspension movement and the fluctuation in conductor rail to running rail distances

Also reported it to NWR, I would guess they already know, but better to be safe than sorry

 

[Deepgreen]

I wouldn't have thought that the collector shoes are pushing down with tons of force, but it must be a few kg worth in order to maintain contact while in motion due to the suspension movement and the fluctuation in conductor rail to running rail distances

Also reported it to NWR, I would guess they already know, but better to be safe than sorry

You would be surprised what NR don't seem to know until it is reported to them. I have reported a very wide and loose track joint (Redhill platform 3, London end) and a missing speed restriction sign (Couldson South, down line, London end), and they were fixed a few days later, suggesting strongly that NR hadn't been aware of the issues before I reported them.

 

[WestRiding]

You would be surprised what NR don't seem to know until it is reported to them. I have reported a very wide and loose track joint (Redhill platform 3, London end) and a missing speed restriction sign (Couldson South, down line, London end), and they were fixed a few days later, suggesting strongly that NR hadn't been aware of the issues before I reported them.

Regarding the Speed Restriction, it had probably been reported many times by passing drivers to the signal box.

 

[SpacePhoenix]

Why can't a few units be retrofitted with cameras and a GPS unit to record the track (the GPS for displaying on screen the location), similar to how some units have got pantograph cameras

 

[edwin_m]

Why can't a few units be retrofitted with cameras and a GPS unit to record the track (the GPS for displaying on screen the location), similar to how some units have got pantograph cameras

Many trains now have forward facing CCTV, as often seen in RAIB reports. Even if they also have GPS the CCTV may not record position, but it would be pretty easy to work it out from the images. However monitoring this to check for absence of lineside signs etc would be a time-consuming task unless done by machine vision against a database of what should be there. Given the duty of drivers to report missing signs this probably isn't worth the cost of developing.

New Measurement Train and similar do use high-speed cameras to look for defects like missing rail clips, as well as having instrumentation to monitor the geometry of the track and OLE and the profile of the running rails. Some service trains even have unattended monitoring systems. I don't know what automated equipment is available to monitor the third rail.

 

[Deepgreen]

This is the third rail at the London end of Redhill's platform 2. The wear down to the webbing is a short section presumably caused by a dip in the running rails. I don't suppose anything dramatic happens when the shoes run on the web, apart from an increased chance of a shoe dropping off the narrower third rail head.

 

[M7R]

Thought I would update this, just had a nice phone call (blocked number btw which I don't normally answer as it's normally just automated tells calls but did this time) from a lady at NWR who thanked me for reporting the conductor rail and confirmed they were aware of it and that it is due to be renewed in the near future, at the next possession it is planned.

A very nice phone call and finished off by thanking me again and said they would always prefer to be told of something even if they possibly know as it is better to be safe than sorry.

 

[jopsuk]

Some new units have track recording cameras- eg the entire 379 fleet, and possibly the 387s?