BEMUs and on-route charging

[norbitonflyer]

Journalists never let the truth get in the way of a good story lol
Imagine if journalists did research before they wrote articles on the railway, we would have good honest articles but unless it's railway based magazines they are usually very inaccurate.

Some railway-based magazines are less than accurate too.

Current issue of RAIL - confuses Stratford International with the other Stratford
- accompanies a photo of the Stadler factory where NEXUS's new units will be built with a caption suggesting that such units are in the picture
- confuses "a Deltic" (Class55) with "the Deltic" (DP1 prototype) - the former did not exist in 1957!
- has a photo of London *Underground "S" (surface) stock captioned as being at "Euston" station, which is only served by Deep Tube lines `

 

[2192]

They don,'t exist in the UK yet do they?

No, but if they did, they would be dead unless a train was on top of them. It's a design feature.

 

[swt_passenger]

Here is a slightly more reliable press article, although this time a 128.74km range is quoted which is 80 miles so why didn't they just say 80 miles?! : https://www.railway-technology.com/news/network-rail-vivarail-train/

I think the railway technology website considers itself “international” so has helpfully converted the figure, but as is so often the case they have used a completely spurious level of accuracy, by going to two decimal places...

 

[AM9]

No, but if they did, they would be dead unless a train was on top of them. It's a design feature.

Just because something exists ouitside the country, it doesn't mean that it will arrive here, be acceptable to the safety authorities or even deemed a worthwhile expense.

 

[DerekC]

Yup. People have yet to realise that nursing adults like babies will only end up in them needing more and more nursing. It will only end in more and more incidents as people get more and more dependant and incapable of thinking for themselves.

That's precisely the argument that was put forward by the railway companies in the 19thC (and even later) to try to avoid the expense of every initiative aimed to improve safety by preventing or trapping human error - block working, interlocking, track circuits, train protection. It still goes down well in the pub but it just isn't true. What does have to be considered, though, is the cost versus the likely benefit in terms of reduced risk.

 

[D365]

Just because something exists ouitside the country, it doesn't mean that it will arrive here, be acceptable to the safety authorities or even deemed a worthwhile expense.

That’s exactly what Vivarail are trying to overcome at the moment!

 

[AM9]

That’s exactly what Vivarail are trying to overcome at the moment!

The Vivarail proposition is on a completely different scale to the problems posed when charging a full performance heavy rail train. To get a reliable charge into a four-car EMU with about 1000kW motors requires at least 500 kWh, so allowing for inefficiencies in the overall system, that word require over 2500A DC switching for 15 minutes per train. To get any reasonable charge in even a sloppy dwell, would be impossible. A permanently powered section of OLE wouldn't have any frequent switching issues, and far less safety problems anyway.

 

[Ken H]

The Vivarail proposition is on a completely different scale to the problems posed when charging a full performance heavy rail train. To get a reliable charge into a four-car EMU with about 1000kW motors requires at least 500 kWh, so allowing for inefficiencies in the overall system, that word require over 2500A DC switching for 15 minutes per train. To get any reasonable charge in even a sloppy dwell, would be impossible. A permanently powered section of OLE wouldn't have any frequent switching issues, and far less safety problems anyway.

Yes. Why would a bit of permanently live 3rd rail at a terminal station away from the network be more dangerous than the 3rd rail at London Bridge or Warren St tube stn?

 

[wobman]

Yes. Why would a bit of permanently live 3rd rail at a terminal station away from the network be more dangerous than the 3rd rail at London Bridge or Warren St tube stn?

It's very much about safety, people forget that outside of the present 3rd / 4th rail systems currently in place. The general public don't understand what it is and there's plenty of areas were trespass is common place and having live rails would have serious safety consequences.

 

[zwk500]

Yes. Why would a bit of permanently live 3rd rail at a terminal station away from the network be more dangerous than the 3rd rail at London Bridge or Warren St tube stn?

You can't ignore standards just because somewhere else is more dangerous. Progress is made by improving on what went before, not by saying 'we've done it before and only a few people have died'.

 

[AM9]

Yes. Why would a bit of permanently live 3rd rail at a terminal station away from the network be more dangerous than the 3rd rail at London Bridge or Warren St tube stn?

A random live conductor at ankle level 'at a terminal station away from the network' would be far more likely to cause injury or death to a person that a whole array of conductors at a major station in the largest contiguous 3rd rail network in Europe, where the station is manned 24/7. Much he same applies to Warren St. Station. Context is everything in safety.
And there's the not insignificant issue of grandfather rights, - there's no way that If London Bridge was built today that it would be considered for 3rd rail.

 

[Ken H]

You can't ignore standards just because somewhere else is more dangerous. Progress is made by improving on what went before, not by saying 'we've done it before and only a few people have died'.

It's not what we have done before. There are hundreds of stations with 3rd rail and no plans to change it. We need to reduce diesel train use for a number of reasons (particulate air pollution being the biggy for me, as it does kill people) and BEMUs are an easy win. Doing it at Uckfield could eliminate diesel working at London Bridge which has to be good. I would also put 3rd rail south from Hurst Green as far as possible without need for additional expensive lines ide equipment.

 

[zwk500]

It's not what we have done before. There are hundreds of stations with 3rd rail and no plans to change it. We need to reduce diesel train use for a number of reasons (particulate air pollution being the biggy for me, as it does kill people) and BEMUs are an easy win. Doing it at Uckfield could eliminate diesel working at London Bridge which has to be good. I would also put 3rd rail south from Hurst Green as far as possible without need for additional expensive lines ide equipment.

This is answering a different question. I was responding to your suggestion that 'We should install dangerous equipment because dangerous equipment is installed elsewhere'. You are now saying 'we should get BEMUs to reduce particulate emissions', which I totally agree with. However there's nothing that says BEMUs in the 3rd rail area need to rely on 3rd rail at new charging points.

 

[AM9]

It's not what we have done before. There are hundreds of stations with 3rd rail and no plans to change it. We need to reduce diesel train use for a number of reasons (particulate air pollution being the biggy for me, as it does kill people) and BEMUs are an easy win. Doing it at Uckfield could eliminate diesel working at London Bridge which has to be good. I would also put 3rd rail south from Hurst Green as far as possible without need for additional expensive lines ide equipment.

So once again, somebody advocating new 3rd rail where it has never been before. That is the nub of the problem. For decades (about 167 years which is over 5 generations!), the local population, (almost all of them who neither know nor care about anything to do with electrified track), have lived with a railway where avoiding trains is the only safety issue.

 

[D821]

We've had 3rd rail railways in Wirral for quite a while and, IMO, we don't get electrocution on a regular basis.

 

[AM9]

We've had 3rd rail railways in Wirral for quite a while and, IMO, we don't get electrocution on a regular basis.

Parts of Merseyrail were electrified in 1903/4, most of the rest in 1938 and a few additions in the '70s to '90s. In more recent years the railway and responsible authorities in general have had a much less casual attitude to the riskes of electrified lines and especially 3rd rail which presents a very real risk to both track workers and trespassing members of the public. Accordingly, there is no permission, (implied or actual) to plan and build new 3rd rail installations but existing ones have grandfather rights for the meantime.

 

[MattRat]

Parts of Merseyrail were electrified in 1903/4, most of the rest in 1938 and a few additions in the '70s to '90s. In more recent years the railway and responsible authorities in general have had a much less casual attitude to the riskes of electrified lines and especially 3rd rail which presents a very real risk to both track workers and trespassing members of the public. Accordingly, there is no permission, (implied or actual) to plan and build new 3rd rail installations but existing ones have grandfather rights for the meantime.

Something I found out recently is that you can have under rail electrification, so the third rail is only live at the bottom. It comes with it's own set of problems, but it does solve the safety issue.

 

[2192]

Just because something exists ouitside the country, it doesn't mean that it will arrive here, be acceptable to the safety authorities or even deemed a worthwhile expense.

It's a British design - the Vivarail people. A new design that was live when there was no train on top of it wuld never get adopted n the UK.

 

[AM9]

It's a British design - the Vivarail people. A new design that was live when there was no train a switched supply would get acceptance in the UK.

What would a stretch of 3rd rail with expensive switching and safety systems do that a 200m length of bog standard OLE couldn't?

 

[CBlue]

Yup. People have yet to realise that nursing adults like babies will only end up in them needing more and more nursing. It will only end in more and more incidents as people get more and more dependant and incapable of thinking for themselves.

I never really wrapped my head around this argument, which also tends to float around whenever discussions like banning smoking in public places rear their heads.

Times move on and what is considered acceptable safety evolves - for the same reasons we no longer allow trains to dump raw sewage on tracks or send children up chimneys to clean them. I don't hear many calls for those practices to come back, oddly....

 

[edwin_m]

Quote from @AM9 (I think): What would a stretch of 3rd rail with expensive switching and safety systems do that a 200m length of bog standard OLE couldn't?

It would avoid the trains on the route having to be fitted with pantographs and transformers, if they don't have them already. It might also be difficult to provide OLE if there were low bridges over the platforms (eg footbridges) or even just off the platform ends - if it was "bog standard OLE" it would have to have a run-off at each end.

 

[SynthD]

Something I found out recently is that you can have under rail electrification, so the third rail is only live at the bottom. It comes with it's own set of problems, but it does solve the safety issue.

It sounds like that solves it for the men in the pub, but not for the ORR. They haven't declared either way and I don't recall seeing some leaked thoughts on the matter.

 

[norbitonflyer]

Something I found out recently is that you can have under rail electrification, so the third rail is only live at the bottom. It comes with it's own set of problems, but it does solve the safety issue.

The DLR uses this system.

There was also the side-contact system installed by the Lancashire & Yorkshire Railway in 1916 on the line from Manchester to Bury - this was at the high voltage of 1200Volts. The live rail had wooden shielding (on both sides, I think) with the shoegear running in the gap between the shielding and the rail. The system was replaced when the line was converted to a tram route in 1992 as the first stage of Metrolink.

Both side- and bottom-contact systems are better able to cope with ice than the conventional top-contact system (or for that matter overhead cables)

== Doublepost prevention - post automatically merged: 10 Oct 2021 ==

Quote from @AM9 (I think): What would a stretch of 3rd rail with expensive switching and safety systems do that a 200m length of bog standard OLE couldn't?

It would avoid the trains on the route having to be fitted with pantographs and transformers, if they don't have them already. It might also be difficult to provide OLE if there were low bridges over the platforms (eg footbridges) or even just off the platform ends - if it was "bog standard OLE" it would have to have a run-off at each end.

It wouldn't need a transformer if the supply was DC. It would need converting to DC anyway if it is to charge a battery. And the low voltage needed by DC (because transformers only work on AC) would not be an issue for transmission losses if the feeder station was adjacent to the charging point (and why wouldn't it be?). OHLE clearances could be smaller for low voltages as well.

 

[edwin_m]

Something I found out recently is that you can have under rail electrification, so the third rail is only live at the bottom. It comes with it's own set of problems, but it does solve the safety issue.

It sounds like that solves it for the men in the pub, but not for the ORR. They haven't declared either way and I don't recall seeing some leaked thoughts on the matter.

From the ORR Policy Statement: ORR’s Policy on Third Rail DC Electrification Systems | Office of Rail and Road

If, at the earliest design optioneering stage, a duty holder fully assesses the risks of a proposed electrification scheme then it is possible to exploit opportunities to design those risks out or minimise them, as required by legislation. For example, later DC systems – such as the DLR – have designed their traction arrangements so that the conductor rail is insulated or shrouded.
...
ORR’s most significant concern in regard to legacy third rail systems (the “legacy network”) is the running of bare, live conductors through publicly accessible areas. These conductors are not insulated or shrouded.

ORR seems to be leaving the door open for bottom-contact systems, while not promising that they will automatically be acceptable.

However there would be real difficulties in implementing bottom contact on the existing main line rail network due to gauging issues, and rather than introducing a new and incompatible system the preference would probably be to go for standard 25kV OLE.

It wouldn't need a transformer if the supply was DC. It would need converting to DC anyway if it is to charge a battery. And the low voltage needed by DC (because transformers only work on AC) would not be an issue for transmission losses if the feeder station was adjacent to the charging point (and why wouldn't it be?). OHLE clearances could be smaller for low voltages as well.

This wouldn't really fit the definition of "bog-standard OLE" that I was responding to, but yes DC overhead would be another possibility. I guess one reason Vivarail prefers third rail is that it would be difficult to fit pantographs to the D78 bodyshell.

 

[AM9]

From the ORR Policy Statement: ORR’s Policy on Third Rail DC Electrification Systems | Office of Rail and Road


ORR seems to be leaving the door open for bottom-contact systems, while not promising that they will automatically be acceptable.

However there would be real difficulties in implementing bottom contact on the existing main line rail network due to gauging issues, and rather than introducing a new and incompatible system the preference would probably be to go for standard 25kV OLE.


This wouldn't really fit the definition of "bog-standard OLE" that I was responding to, but yes DC overhead would be another possibility. I guess one reason Vivarail prefers third rail is that it would be difficult to fit pantographs to the D78 bodyshell.

But unless part of a scheme to convert all existing 3rd rail to some new bottom contact standard, creating a ,new heavy rail electrification (and loading gauge) standard for the sake of using metro rolling stock out of its original intended role seems a bit of a faux pas.

 

[Nicholas Lewis]

From the ORR Policy Statement: ORR’s Policy on Third Rail DC Electrification Systems | Office of Rail and Road


ORR seems to be leaving the door open for bottom-contact systems, while not promising that they will automatically be acceptable.

However there would be real difficulties in implementing bottom contact on the existing main line rail network due to gauging issues, and rather than introducing a new and incompatible system the preference would probably be to go for standard 25kV OLE.

Your not going to be able to fit top and bottom/side contact on the same unit unless they are fully retractable clear of conductor rail infrastructure. Top running conductor shoegear retraction is practical but side or bottom contact would be more involved. A safety case for switchable conductor rail for charging purposes will have safety factor considerably higher than an exposed conductor rail with unrestricted access so I believe they will be able to make the case with ORR.

This wouldn't really fit the definition of "bog-standard OLE" that I was responding to, but yes DC overhead would be another possibility. I guess one reason Vivarail prefers third rail is that it would be difficult to fit pantographs to the D78 bodyshell.

Stationary pantographs are limited to how much current can be transferred across the interface without causing overheating which is a problem for rapid charging as it needs high current transfer albeit for a limited period of time whereas shoegear has a much higher surface area to transmit the current. Charging via AC is going to need a transformer to be lugged around and not sure there is room under a D78 for one.

 

[norbitonflyer]

However there would be real difficulties in implementing bottom contact on the existing main line rail network due to gauging issues,

I was considering a shrouded system (bottom or side contact) for a battery charging facility on a standalone route where no existing power supply is available - or at least no live-rail system. If battery operation is envisaged to extend a service beyond the limits of an existing 3rd rail system (e.g Wrexham, Uckfield, Helsby, Skelmersdale, Preston via Burscough - even possibly Aylesbury or Salisbury), batteries can be topped up whilst the train is running on that part of its route which is part of the existing "grandfathered" legacy live rail network.
In some cases, such as Bidston, it might require extended dwell time at the electrified terminus, or extending services beyond the existing terminus.

 

[edwin_m]

Your not going to be able to fit top and bottom/side contact on the same unit unless they are fully retractable clear of conductor rail infrastructure. Top running conductor shoegear retraction is practical but side or bottom contact would be more involved. A safety case for switchable conductor rail for charging purposes will have safety factor considerably higher than an exposed conductor rail with unrestricted access so I believe they will be able to make the case with ORR.

Stationary pantographs are limited to how much current can be transferred across the interface without causing overheating which is a problem for rapid charging as it needs high current transfer albeit for a limited period of time whereas shoegear has a much higher surface area to transmit the current. Charging via AC is going to need a transformer to be lugged around and not sure there is room under a D78 for one.

Good points which I agree with.

I was considering a shrouded system (bottom or side contact) for a battery charging facility on a standalone route where no existing power supply is available - or at least no live-rail system. If battery operation is envisaged to extend a service beyond the limits of an existing 3rd rail system (e.g Wrexham, Uckfield, Helsby, Skelmersdale, Preston via Burscough - even possibly Aylesbury or Salisbury), batteries can be topped up whilst the train is running on that part of its route which is part of the existing "grandfathered" legacy live rail network.
In some cases, such as Bidston, it might require extended dwell time at the electrified terminus, or extending services beyond the existing terminus.

In this situation a bottom-contact system would still need retractable shoegear, or increased lower clearances on all routes those trains use. The third rail has to be clear of the gauge so it doesn't foul anything, so the shoes that touch it must also be outside the normal gauge.

 

[Ken H]

I was considering a shrouded system (bottom or side contact) for a battery charging facility on a standalone route where no existing power supply is available - or at least no live-rail system. If battery operation is envisaged to extend a service beyond the limits of an existing 3rd rail system (e.g Wrexham, Uckfield, Helsby, Skelmersdale, Preston via Burscough - even possibly Aylesbury or Salisbury), batteries can be topped up whilst the train is running on that part of its route which is part of the existing "grandfathered" legacy live rail network.
In some cases, such as Bidston, it might require extended dwell time at the electrified terminus, or extending services beyond the existing terminus.

Uckfield is a fair way from Hurst Green. Would an out and back working exhaust the batteries on a winters day (Lights, heating, wipers etc all on) or would it need a top up at Uckfield?
Would trains stabled at Uckfield need topping up overnight to get them to Hurst Green?

If they were to have top contact conductor rail only live when a train was there, how would you cope with different length trains? A 4 car would leave exposed 3rd rail. if you only had a 4 car length electrified then it would not work with units in multiple.

And how many trains would you stable at night. How much demand would they have? What would all that kit cost. And is that sort of power available from the local power network?

How would you stop a train starting drawing big amps from the 3rd rail and tripping the circuit breakers?

 

[hwl]

I was considering a shrouded system (bottom or side contact) for a battery charging facility on a standalone route where no existing power supply is available - or at least no live-rail system. If battery operation is envisaged to extend a service beyond the limits of an existing 3rd rail system (e.g Wrexham, Uckfield, Helsby, Skelmersdale, Preston via Burscough - even possibly Aylesbury or Salisbury), batteries can be topped up whilst the train is running on that part of its route which is part of the existing "grandfathered" legacy live rail network.
In some cases, such as Bidston, it might require extended dwell time at the electrified terminus, or extending services beyond the existing terminus.

Uckfield is a fair way from Hurst Green. Would an out and back working exhaust the batteries on a winters day (Lights, heating, wipers etc all on) or would it need a top up at Uckfield?
Would trains stabled at Uckfield need topping up overnight to get them to Hurst Green?

If they were to have top contact conductor rail only live when a train was there, how would you cope with different length trains? A 4 car would leave exposed 3rd rail. if you only had a 4 car length electrified then it would not work with units in multiple.

And how many trains would you stable at night. How much demand would they have? What would all that kit cost. And is that sort of power available from the local power network?

How would you stop a train starting drawing big amps from the 3rd rail and tripping the circuit breakers?

One of the problems with "Uckfield" is that the supply north of Hurst Green doesn't have much head room for running more 3rd rail train let alone charging batteries too.

T1214 should clarify the position on risk mitigation for additional 3rd rail in the near future.