RIP Great western 125mph.... (IETs to have speed limiter automatically set)

[Fragezeichnen]

Since 1979 most passenger locomotives built in Germany have had a automatic speed control fitted. Drivers are encouraged(though not required) to use it and the majority do. Not only does it reduce workload when running long distances at high speeds, and prevent accidental overspeed, it can also be used as a reminder of the current restriction, e.g. if running through a long TSR. The sky hasn't fallen in yet.

The hyperbole in this thread related to the supposed dangers and de-skilling merely from having it enabled and set to the maximum speed of the traction seems to me overblown.

Under the standardised cab design used in Europe, there is a physical two position switch to enable and disable the system, and a lever used to set the speed. There is also an audible voice prompt when the system is enabled or disabled, similar to when the vigilance alarm needs to be reset, or there is an emergency brake intervention. It sounds like in the design cab was a significant failure to appreciate the safety implications of the speed control system having an ambiguous state.

 

[zwk500]

Since 1979 most passenger locomotives built in Germany have had a automatic speed control fitted. Drivers are encouraged(though not required) to use it and the majority do. Not only does it reduce workload when running long distances at high speeds, and prevent accidental overspeed, it can also be used as a reminder of the current restriction, e.g. if running through a long TSR. The sky hasn't fallen in yet.

The hyperbole in this thread related to the supposed dangers and de-skilling merely from having it enabled and set to the maximum speed of the traction seems to me overblown.

Under the standardised cab design used in Europe, there is a physical two position switch to enable and disable the system, and a lever used to set the speed. There is also an audible voice prompt when the system is enabled or disabled, similar to when the vigilance alarm needs to be reset, or there is an emergency brake intervention. It sounds like in the design cab was a significant failure to appreciate the safety implications of the speed control system having an ambiguous state.

This system sounds much closer to Automatic Train Protection, where the supervision follows the permitted linespeed. Nobody is doubting the value of that. This system is installed on the Great Western Main Line and Chiltern Main Line in the UK, and when ETCS finally rolls around it will also provide this functionality. I believe one form of ATP used in Britain is based on LZB.

What is being discussed on this thread is that the train has it's own limiter set to 200km/h at all times, which will do nothing to improve safety at limits below 200km/h but could lead to drivers relying on the limiter to keep at top speed rather than driving proactively. The original objection was that 200km/h rounded to 124mph rather than 125mph, but that's got a bit lost in the debate around driver attention.

 

[Irascible]

This system sounds much closer to Automatic Train Protection, where the supervision follows the permitted linespeed. Nobody is doubting the value of that. This system is installed on the Great Western Main Line and Chiltern Main Line in the UK, and when ETCS finally rolls around it will also provide this functionality. I believe one form of ATP used in Britain is based on LZB.

The Chiltern one was a development of LZB, the GW one is... Belgian, I want to say. If we think maintaining early AC traction is bad, I'd hate to be supporting either ATP system...

 

[zwk500]

The Chiltern one was a development of LZB, the GW one is... Belgian, I want to say. If we think maintaining early AC traction is bad, I'd hate to be supporting either ATP system...

Yes, that makes sense. GW based on the Belgian Crocodile I think. IIRC the Chiltern one has been declared obsolete and there's an ongoing debate about whether it can hang on until ETCS or if TPWS++ will be sufficient to avoid a safety gap. Not sure on the GW one, does it have ETCS L2 overlay coming in?

 

[Fragezeichnen]

This system sounds much closer to Automatic Train Protection, where the supervision follows the permitted linespeed. Nobody is doubting the value of that. This system is installed on the Great Western Main Line and Chiltern Main Line in the UK, and when ETCS finally rolls around it will also provide this functionality. I believe one form of ATP used in Britain is based on LZB.

I don't really understand where you got that from. Train protection and speed control are fundamentally different functionality. One is there to intervene in unsafe situations and does nothing otherwise, the other maintains continous control of traction and braking. The system I am describing called AFB, and it is speed control, not train protection. I also clearly stated that the speed is manually set.

Under the standardised cab design used in Europe, there is a physical two position switch to enable and disable the system, and a lever used to set the speed.

It's true that the same system can be linked to a continuous train protection system such as LZB or ETCS and in that case if the speed selected by the driver is lower than the permitted speed the target speed will be reduced, but it would normally be used regardless of whether this information is available.

 

[Irascible]

Yes, that makes sense. GW based on the Belgian Crocodile I think. IIRC the Chiltern one has been declared obsolete and there's an ongoing debate about whether it can hang on until ETCS or if TPWS++ will be sufficient to avoid a safety gap. Not sure on the GW one, does it have ETCS L2 overlay coming in?

I could nebulously claim to be a professional in the area for a brief period of time ( quite some years ago ), but that would be overselling the actual job so someone in current S&T will have to let us know there. The Chiltern route does seem to be a suitable place for some experimentation or even just implementation experience, given it's pretty simple & self-contained bar that awkward shared bit at one end.

 

[RollingStock19]

Already done to the TPE 802s. Not sure about LNER's 80xs, Hull Trains's 802s or Lumo's 803s.

Came fitted on delivery of the 803s

And it's probably TPEs fault that this is being done in the first place after one of their drivers had a little oopsie on the race track between York and Northallerton...

I'm pretty sure LNER have had one or two, I'm aware of one in the last 18-24months where the speed topped 140mph

Does the speed limiter have an autobrake? If not it may still be possible to achieve 125 on a downhill gradient.

Not sure if its an autobrake as such, but if you left the CPBC in power the train will automatically stop power. I've not noticed any brake demand when it hots 125

I've never seen the speed go over 125mph, even down Stoke bank.. it usually sits at 124mph. However I have noticed if you use the speed limiter for a lower speed, for example I was recently routed on a slow line I don't use a lot and the speeds go up and down 75/80 frequently so I set the limiter for 75mph and it often crept up to 76/77mph. I don't often use it on the go as its just one more thing to mess around with causing distraction but will use it on slower lines where I'm used to running at 125mph on the adjacent lines.

 

[ainsworth74]

I'm pretty sure LNER have had one or two, I'm aware of one in the last 18-24months where the speed topped 140mph

Unless LNER have done it as well that 140mph incident was the TPE one I was referring to. Sadly I've since lost it but the log entry for that was a masterful display of restraint and understatement by whoever wrote it as I recall

 

[Irascible]

I've never seen the speed go over 125mph, even down Stoke bank.. it usually sits at 124mph. However I have noticed if you use the speed limiter for a lower speed, for example I was recently routed on a slow line I don't use a lot and the speeds go up and down 75/80 frequently so I set the limiter for 75mph and it often crept up to 76/77mph. I don't often use it on the go as its just one more thing to mess around with causing distraction but will use it on slower lines where I'm used to running at 125mph on the adjacent lines.

Just stop the speedo reading abover 124mph, all problems solved

 

[RollingStock19]

Unless LNER have done it as well that 140mph incident was the TPE one I was referring to. Sadly I've since lost it but the log entry for that was a masterful display of restraint and understatement by whoever wrote it as I recall

Yeah there deffo was one... it was round about the same time they had the "oopsie" at Neville Hill. I believe it was around 143/144mph they clocked up.

I was under the impression that if you exceeded 128mph the train would snitch you up to Hitachi

 

[tpjm]

And it's probably TPEs fault that this is being done in the first place after one of their drivers had a little oopsie on the race track between York and Northallerton...

Whilst it won't affect schedules I think its a shame, and completely the fault of the TPE driver who cocked it up for everyone.

As ever on this forum, I would implore members to take stock of their comments before posting. There have been several incidents of 80x units over-speeding at quite a number of TOCs.

For those who have never driven one, or indeed sat in the second man's seat, the driving position and shape of the nose means your immediate viewing angle is quite a bit further into this distance when compared to driving other classes. This gives a weird perception that you are travelling much slower than you actually are.

Following a spate of incidents, and before this limit came in, Hitachi implemented processes to report when trains exceeded 128mph which sent a notification to the TOC control. I'm aware of at least one instance where a unit was undergoing maintenance and we got a notification that it had breached the threshold when it was indeed sat on Craigentinny going nowhere, so it definitely works.

I'm not going to go into the details of the other incidents, but this is certainly not just one driver who messed up at TPE.

 

[Railperf]

As ever on this forum, I would implore members to take stock of their comments before posting. There have been several incidents of 80x units over-speeding at quite a number of TOCs.

For those who have never driven one, or indeed sat in the second man's seat, the driving position and shape of the nose means your immediate viewing angle is quite a bit further into this distance when compared to driving other classes. This gives a weird perception that you are travelling much slower than you actually are.

Following a spate of incidents, and before this limit came in, Hitachi implemented processes to report when trains exceeded 128mph which sent a notification to the TOC control. I'm aware of at least one instance where a unit was undergoing maintenance and we got a notification that it had breached the threshold when it was indeed sat on Craigentinny going nowhere, so it definitely works.

I'm not going to go into the details of the other incidents, but this is certainly not just one driver who messed up at TPE.

Commom sense suggests it would have been better to have set a limiter up at 128mph at that time rather than setting the train to report breaches of that limit.
If we are talking in metric..then a 205 km/h limiter for nornally signalled lines and a 230 km/h limiter when used under ETCS should have been specified and built in from the start.

 

[irish_rail]

As ever on this forum, I would implore members to take stock of their comments before posting. There have been several incidents of 80x units over-speeding at quite a number of TOCs.

For those who have never driven one, or indeed sat in the second man's seat, the driving position and shape of the nose means your immediate viewing angle is quite a bit further into this distance when compared to driving other classes. This gives a weird perception that you are travelling much slower than you actually are.

Following a spate of incidents, and before this limit came in, Hitachi implemented processes to report when trains exceeded 128mph which sent a notification to the TOC control. I'm aware of at least one instance where a unit was undergoing maintenance and we got a notification that it had breached the threshold when it was indeed sat on Craigentinny going nowhere, so it definitely works.

I'm not going to go into the details of the other incidents, but this is certainly not just one driver who messed up at TPE.

Right , but for the umpteenth time these overspeeds are NOT occurring on ATP fitted GWR which is whats being debated. I've no doubt the ECML is a cowboys plaything, I'm talking about the Western.

You make a fair point about poor speed perception from the cab. This is partly exacerbated by the poor drivers seat which is very difficult to get to sit high enough up forcing the driver to sit lower down than desired, and therefore getting quite a poor view over the drivers desk. This is further impeded by the daft strip of carpet that further blocks the drivers view. I have highlighted this to drivers managers as something which does have an effect when stopping at stations as it is very easy to hit platforms faster than desired. The speed set of course will have no help in this aspect of driving however.

== Doublepost prevention - post automatically merged: 14 Jul 2022 ==

Commom sense suggests it would have been better to have set a limiter up at 128mph at that time rather than setting the train to report breaches of that limit.
If we are talking in metric..then a 205 km/h limiter for nornally signalled lines and a 230 km/h limiter when used under ETCS should have been specified and built in from the start.

Absolutely this would be the common sense answer, but the railway doesn't have a great history of applying common sense lately!

 

[Agent_Squash]

Right , but for the umpteenth time these overspeeds are NOT occurring on ATP fitted GWR which is whats being debated. I've no doubt the ECML is a cowboys plaything, I'm talking about the Western.

Looks like the cowboys have moved then!

In an ideal world, the limit would be set slightly above to allow for any discrepancies / not put the driver into a position where they can't use the CPBC as intended as the speed was right on the edge of 125/26.

But from a safety point of view, if it's possible to stop the train going over it's maximum speed limit on the lines it operates on (which is, despite all the fuss, all this is) then we should be going for it. Most of the day is spent operating at 124mph anyway.

 

[tpjm]

Commom sense suggests it would have been better to have set a limiter up at 128mph at that time rather than setting the train to report breaches of that limit.
If we are talking in metric..then a 205 km/h limiter for nornally signalled lines and a 230 km/h limiter when used under ETCS should have been specified and built in from the start.

You can’t just roll out new software onto a train overnight without the necessary testing and engineering change procedures being followed. Implementing software on a shore-side management system to utilise existing data-feeds is a much quicker process and a provides a real time reporting tool and serves as a useful exercise to understand how often it happens.

 

[niggill617@gma]

ATP fitted lines no limiter, driver suddenly gets alarm 128 mph on the speedo. By the time the brake is applied the set could easily be doing 129 mph. Limiter fitted train remains at 124.27 mph. The difference in emergency braking displacement is around 100 m on the level.

Possibly the difference between: a close one and death and destruction.

 

[notadriver]

Wikipedia has altered the maximum for class 80x to 124 mph meaning they can no longer officially attain the maximum line speed of 125 mph on the UK. The general sustained cruising speed seems to be 123 mph - slower than older stock that preceded it.

 

[Bletchleyite]

Wikipedia has altered the maximum for class 80x to 124 mph meaning they can no longer officially attain the maximum line speed of 125 mph on the UK. The general sustained cruising speed seems to be 123 mph - slower than older stock that preceded it.

It's 200km/h, which is 124mph to the nearest 1mph.

 

[ainsworth74]

Wikipedia has altered the maximum for class 80x to 124 mph meaning they can no longer officially attain the maximum line speed of 125 mph on the UK.

Wikipedia hasn't done anything. An individual has edited Wikipedia to reflect that change. That's the whole point of Wikipedia, individuals working together to create the encyclopaedia

 

[karlbbb]

It's 200km/h, which is 124mph to the nearest 1mph.

Perhaps we should switch to km/h on the railways if it's all about the biggest number

 

[Hophead]

Wikipedia hasn't done anything. An individual has edited Wikipedia to reflect that change. That's the whole point of Wikipedia, individuals working together to create the encyclopaedia

Wikipedia has altered the maximum for class 80x to 124 mph meaning they can no longer officially attain the maximum line speed of 125 mph on the UK.

Neither are speed limits, whether on rail or road, governed by what is written in an online encyclopaedia!

 

[uvarvu]

Wikipedia hasn't done anything. An individual has edited Wikipedia to reflect that change. That's the whole point of Wikipedia, individuals working together to create the encyclopaedia

Was it @Irish Rail

 

[hexagon789]

It's 200km/h, which is 124mph to the nearest 1mph.

It isn't, the limiter is set to 201km/h - so 124.89mph.

(And before anyone asks, I have THREE separate sources agreeing on that figure, from two different TOCs (LNER and GWR).

I posted this before but it was ignored.

 

[507020]

It isn't, the limiter is set to 201km/h - so 124.89mph.

(And before anyone asks, I have THREE separate sources agreeing on that figure, from two different TOCs (LNER and GWR).

I posted this before but it was ignored.

But why, even if the limiter can’t accept imperial measurements, can’t it be set to 201.168km/h, which is the actual maximum permissible speed in this country?

 

[hexagon789]

But why, even if the limiter can’t accept imperial measurements, can’t it be set to 201.168km/h, which is the actual maximum permissible speed in this country?

Presumably 201 is good enough for schedules and works for future ETCS operation in metric.

 

[irish_rail]

Was it @Irish Rail

Haha my hat off to whoever is responsible i must admit. I managed 125mph on an IET recently (downhill on Dauntsey bank) , but yeah as others have said, 124mph is the new maximum. And without going into too much detail , the enforced speed set has already caught out one driver at one point causing quite a severe overspeed (although not one GWR are aware of) , just going on what he told me. And it rather backs up some of my original views....

 

[physics34]

Is it true the dutch have a system where a display tells the driver to obey a certain speed to keep a distance from the train in front rather than obeying signals

 

[XAM2175]

Haha my hat off to whoever is responsible i must admit.

It's sourced to an article in last month's edition of The Railway Magazine as Wikipedia policy requires, so it's not really any special achievement

And without going into too much detail , the enforced speed set has already caught out one driver at one point causing quite a severe overspeed (although not one GWR are aware of) , just going on what he told me. And it rather backs up some of my original views....

What would have happened in this circumstance had the limiter not been upper-bounded at 124 mi/h?

Is it true the dutch have a system where a display tells the driver to obey a certain speed to keep a distance from the train in front rather than obeying signals

The Dutch? No. They have a system called ATB that tells the driver the maximum speed for the block they're in (with some limitations), but it still uses fixed blocks and lineside signals. TVM in France and LZB in Germany both allow fully in-cab signalling, as will ECTS which replaces them and is being deployed here too - but even then moving-block operation is a long long way away.

 

[alxndr]

But why, even if the limiter can’t accept imperial measurements, can’t it be set to 201.168km/h, which is the actual maximum permissible speed in this country?

If it can't accept imperial measurements its even less likely to be able to accept decimal ones. You could maybe reprogram it to accept a float (decimal figure) instead of an integer, but is it really necessary for such a small rounding error? The cost and effort of doing so doesn't seem worth it for a train traveling at a consistent speed to be able to cover an extra 193.6 yards in an hour. Realistically the only benefit for doing so is bragging rights, far more time will be lost during a journey due to other factors.

 

[irish_rail]

What would have happened in this circumstance had the limiter not been upper-bounded at 124 mi/h?

After running on the speed limiter for the past hour or so, it can hardly be surprising that when getting onto the b and h , said drivers attention lapsed somewhat and he went rather more than 100mph on b and h when opening it up after Southcote junction. Or so he says. I can not confirm any of this perhaps just hearsay and messroom gossip.......probably just bull