My Ideas for 3rd Rail Expansion

[yorksrob]

For many years we had a sensible convention that new third rail was limited to infill and small extensions within the existing third rail areas.

Then the lunacy set in.

 

[anthony263]

I do think we should see some 3rd rail electrification examples being filling g in southern diesel islands releasing the class 171s to go to EMR and extensions from Bassingstoke to Salisbury at least as well as from Salisbury to Southampton central allowing some of Swrs class 158s to be replaced by Emus

 

[Gareth]

For many years we had a sensible convention that new third rail was limited to infill and small extensions within the existing third rail areas.

Then the lunacy set in.

That was always how I interpreted the guidance. The ORR appears to interpret it differently. Although I have to wonder sometimes if it's just people on here wrongly interpreting the ORR's interpretation.

 

[yorksrob]

That was always how I interpreted the guidance. The ORR appears to interpret it differently. Although I have to wonder sometimes if it's just people on here wrongly interpreting the ORR's interpretation.

It could be an issue if no one has actually asked the ORR to do a third rail extension - I must admit, I don't know when the last scheme was actually proposed.

I'd hope the ORR would clarify though.

 

[Dr Hoo]

It could be an issue if no one has actually asked the ORR to do a third rail extension - I must admit, I don't know when the last scheme was actually proposed.

I'd hope the ORR would clarify though.

What exactly is 'unclear' about the policy that was published as long ago as March 2015? See ORR’s Policy on Third Rail DC Electrification Systems

Various sections of secondary and tertiary route with 1-2 trains per hour have been electrified at 25kV with OHLE over the years and many current types of rolling stock have dual system capability. So it is a big ask to justify using an obsolete [pre current Electricity at Work legislation] system that has several times the safety risk when a much safer alternative seems reasonably practicable elsewhere.

 

[yorksrob]

What exactly is 'unclear' about the policy that was published as long ago as March 2015? See ORR’s Policy on Third Rail DC Electrification Systems

Various sections of secondary and tertiary route with 1-2 trains per hour have been electrified at 25kV with OHLE over the years and many current types of rolling stock have dual system capability. So it is a big ask to justify using an obsolete [pre current Electricity at Work legislation] system that has several times the safety risk when a much safer alternative seems reasonably practicable elsewhere.

Oh, so the policy has been published. Thank you for linking.

It can only confirm the stupidity of banning an electrification system on one route out of Ashford Kent (as an example) as "unsafe" when it is accepted as safe on the other four.

 

[Romsey]

I would suggest that an OHLE failure really screws operations, whereas a 3rd rail failure still allows some form of operations. ( Please refer to ECML or West Anglia every winter.)

OHLE has the advantage it doesn't need to be switched off for tamping or on track work without cranes or lifting such as S&T maintenance.
3rd rail isolations can be much more closely aligned to possession limits with the use of circuit breakers or sometimes hook switches. ( Remote operated hook switches are being introduced.)
OHLE isolations are breaker to breaker so that is why pairs of lines are taken out for maybe 40 miles on the WCML for a 1 mile worksite.
OHLE is more liable to damage from windblown debris
3rd rail is more liable to icing problems.

Contact with the 3rd rail sometimes isn't fatal. (But don't try it!)

Having worked on routes with both systems in a planning role, I would suggest that 3rd rail allows a better chance of working around problems. 3rd rail is lightly less safe - rule one: if you don't understand the isolation limits get the PICOP to explain them. If you haven't seen the isolation docket - no go.

 

[MarkyT]

For new 3rd rail extensions beyond trivial chords and additional parallel tracks and siding I propose the following for risk mitigation:

A discontinuous electrification configuration that locates lengths of live 3rd rail well away from platforms and level crossings, while allowing the batteries installed on board all trains using the infrastructure to slow recharge en route while traction power is drawn from the conductor during the lower power 'cruise phase' of each movement. Thus, battery size and weight can be minimised. Batteries could also recapture regenerated braking energy approaching stations.

Fine-grained remote isolation switching of the conductor rail sections from the signalling control centre could be arranged to allow quick isolation in the event of any reported trespass incidents, and obstacle detection at remaining crossings could automatically detect any incursions with control centre alarms and automatic isolations, while trains could continue to move in the area (under caution clearly) using battery power, which could also cover for local supply failures or planned isolations for maintenance and at least always be able to get a train as far as the next station.

As many footpath and private occupation crossings as possible closed to minimise potential trespass access points and any that are impossible to remove to be fitted with the OD type sensors.

 

[furnessvale]

Contact with the 3rd rail sometimes isn't fatal. (But don't try it!)

The same goes for OHLE but I would be even less inclined to try it.

I know a case of an S&T man who made contact with the OHLE via a length of conduit he was banging on the rail to clear it of debris. He survived but it blew his toes off!

 

[Dr Hoo]

Oh, so the policy has been published. Thank you for linking.

It can only confirm the stupidity of banning an electrification system on one route out of Ashford Kent (as an example) as "unsafe" when it is accepted as safe on the other four.

In most aspects of railway operations and safety things 'move on'. The Kent Coast electrification scheme was authorised in February 1956, based on pre-War Southern Railway plans. It was an era of Mark I rolling stock with very poor collision resistance, un-locked slam doors, droplights, track dump toilets, no AWS, TPWS, OTMR, radio communication, forward facing CCTV, etc.; running on jointed track, on wooden sleepers, past some un-braked freight trains, controlled by oil-lit or non-lamp-proved signals; driven by staff who were not subject to modern methods of competency management, fatigue analysis and so forth; past on-track staff who didn't have hi-vi or other PPE. You get the picture.

Almost every aspect in this picture is now safer, with the glaring exception of an un-protected power supply at lethal voltage at ground level where staff have to work, trespassers may enter and passengers may evacuate. This equipment would be treated as 'illegal' in any other setting under the 1989 Electricity at Work legislation.

I have recounted my own working experiences on this Forum on several previous occasions. After ten years of blithely working with the third rail in North London, on Merseyside and Kent I then had to deal with the electrocution of a nine-year-old boy who had got onto the line through a hole in the fence made by rail staff to create a shortcut to a depot, followed shortly afterwards by having a very experienced trackman electrocuted while he was right next to me because of some appalling procedural failings.

Extension of this system when there are obvious alternatives would be true 'stupidity'.

 

[MarkyT]

I have recounted my own working experiences on this Forum on several previous occasions. After ten years of blithely working with the third rail in North London, on Merseyside and Kent I then had to deal with the electrocution of a nine-year-old boy who had got onto the line through a hole in the fence made by rail staff to create a shortcut to a depot, followed shortly afterwards by having a very experienced trackman electrocuted while he was right next to me because of some appalling procedural failings.

Extension of this system when there are obvious alternatives would be true 'stupidity'.

I think in conjunction with some safeguards I listed above https://www.railforums.co.uk/threads/my-ideas-for-3rd-rail-expansion.204801/page-2#post-4601885 3rd rail could be made a lot safer. Particularly the remote (signaller controlled) isolation switching I suggest, the avoidance of conductor in most stations and around level crossings and provision of traction batteries on board train in a discontinuous electrification configuration. Switched sections in certain platforms might be considered, particularly at termini or other places where long layovers are scheduled for charging. This is effectively a battery operation but using discontinuous 3rd rail to limit battery size and weight. I agree I certainly wouldn't choose the system it for any major new electrification schemes, but moderate, and even quite lengthy extensions of existing networks in the south and perhaps Merseyside, possibly Chilterns (4-rail) to Amersham might be justifiable with the safeguards listed.

 

[yorksrob]

In most aspects of railway operations and safety things 'move on'. Then Kent Coast electrification scheme was authorised in February 1956, based on pre-War Southern Railway plans. It was an era of Mark I rolling stock with very poor collision resistance, un-locked slam doors, droplights, track dump toilets, no AWS, TPWS, OTMR, radio communication, forward facing CCTV, etc.; running on jointed track, on wooden sleepers, past some un-braked freight trains, controlled by oil-lit or non-lamp proved signals; driven by staff who were not subject to modern methods of competency management, fatigue analysis and so forth; past on-track staff who didn't have hi-vi or other PPE. You get the picture.

Almost every aspect in this picture is now safer, with the glaring exception of an un-protected power supply at lethal voltage at ground level where staff have to work, trespassers may enter and passengers may evacuate. This equipment would be treated as 'illegal' in any other setting under the 1989 Electricity at Work legislation.

I have recounted my own working experiences on this Forum on several previous occasions. After ten years of blithely working with the third rail in North London, on Merseyside and Kent I then had to deal with the electrocution of a nine-year-old boy who had got onto the line through a hole in the fence made by rail staff to create a shortcut to a depot, followed shortly afterwards by having a very experienced trackman electrocuted while he was right next to me because of some appalling procedural failings.

Extension of this system when there are obvious alternatives would be true 'stupidity'.

Overhead line electrification could be accidentally re-energised because of proceedural failings.

Overhead power lines can be touched by trespassers climbing on structures or even non-trespassers flying a kite.

The fact that you are ignoring is that any uncovered power source is dangerous. However there is no better way for powering the movement of heavy vehicles, which is why it is stupid not to be filling in diesel islands by whatever the power supply happens to be.

 

[AM9]

... The fact that you are ignoring is that any uncovered power source is dangerous. However there is no better way for powering the movement of heavy vehicles, which is why it is stupid not to be filling in diesel islands by whatever the power supply happens to be.

There is a world of difference between:

an uncovered power source at ankle level, that can be lethal to a trackworker, a guard/driver in the event of technical incidents, and any track trespass activities​

and​

an uncovered power source at a height of at least 4.5m above track level and 3.5m above any surface upon which people are likely to stand​

For these reasons, the number of incidents of electrocution and/or life-changing shock by each power source reflects very badly on 3rd rail despite the system being present on just over half of the total length of electrified line. In addition, many of those are of staff undergoing their duties whereas accidents involving shocks from OLE are comapratively rare.

 

[grangergranger]

This may not exactly be 3rd rail expansion, but 3rd rail can be installed at stations with no OHLE. But for battery charging instead via a contact shoe.
Northern raised this as a possibility at Windermere station.