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The German safety system takes a different approach to try and avoid drivers sticking exactly to the highest possible safe speed. When passing a signal warning of an approaching red signal, the driver knows they have a certain number of seconds to slow down to a certain speed, whilst staying within a braking curve. However, the countdown of the time to reach the target speed is not revealed, nor is the current braking curve target speed.
Ultimately with ETCS you solve the problem by having multiple curves - a target curve, a warning curve, and an intervention curve, amongst others.
As mentioned driving without route knowledge is possible in Germany, and I guess in some other European countries, however this is not normal practice, there are some conditions:
The train cannot exceed 60mph
The driver must consent
The TOC must consent(they might refuse in case of a newly qualified or under investigation driver)
The line must not have any unusual features like very steep gradients
The purpose must be an unscheduled diversion or a one-off trip(e.g. delivering a unit for heavy overhaul, visit to enthusiast festival), not a regular scheduled run
Furthermore, the network has some differences which make this easier:
Extensive signage including
large reflective "mileposts" every 200 metres
countdown boards for distant signals
countdown boards for poorly visible stations
Speed-based signalling
"timetable books" giving the
maximum speed(and necessary speed adjustments for low brake effort)
locations of signals, stations, tunnels and gradients
a safety system monitoring and enforcing a safe approach to red signals which has been around for many decades
I do find it a bit surprising that the UK relies so completely on driver mental knowledge, with no electronic or paper aids in the cab to assist, however it seems like DAS are starting to make inroads anyhow, even if they are not in a safety critical role.
I forgot to mention the views of the RSSB professionals, see redacted minutes attached.
Do you really need to sit with Nellie for hours on end to understand 4 aspect appendix C level gradient braking strategy, absolutely not. A very simple parameter can explain it. Six percent g braking points are also easily explained. The time spent route learning can be shortened. I appreciate running over the route needs a degree of actual practice.
I forgot to mention the views of the RSSB professionals, see redacted minutes attached.
Do you really need to sit with Nellie for hours on end to understand 4 aspect appendix C level gradient braking strategy, absolutely not. A very simple parameter can explain it. Six percent g braking points are also easily explained. The time spent route learning can be shortened. I appreciate running over the route needs a degree of actual practice.
The psychologists deduce; drivers that know the trip speed, will drive to just below the said speed, and risk incident. The truth is all drivers are treated by the actions of the lowest common denominator.
I think that might be more to do with power trips than psychologists! Actually at my last TOC I can remember seeing a booklet with TPWS trigger speeds at a few incident prone locations. I don’t think there was any concern that people drove differently as a result of this knowledge.
You might also want to upload a properly redacted version of that document?!
The German safety system takes a different approach to try and avoid drivers sticking exactly to the highest possible safe speed. When passing a signal warning of an approaching red signal, the driver knows they have a certain number of seconds to slow down to a certain speed, whilst staying within a braking curve. However, the countdown of the time to reach the target speed is not revealed, nor is the current braking curve target speed.
Ultimately with ETCS you solve the problem by having multiple curves - a target curve, a warning curve, and an intervention curve, amongst others.
As mentioned driving without route knowledge is possible in Germany, and I guess in some other European countries, however this is not normal practice, there are some conditions:
The train cannot exceed 60mph
The driver must consent
The TOC must consent(they might refuse in case of a newly qualified or under investigation driver)
The line must not have any unusual features like very steep gradients
The purpose must be an unscheduled diversion or a one-off trip(e.g. delivering a unit for heavy overhaul, visit to enthusiast festival), not a regular scheduled run
Furthermore, the network has some differences which make this easier:
Extensive signage including
large reflective "mileposts" every 200 metres
countdown boards for distant signals
countdown boards for poorly visible stations
Speed-based signalling
"timetable books" giving the
maximum speed(and necessary speed adjustments for low brake effort)
locations of signals, stations, tunnels and gradients
a safety system monitoring and enforcing a safe approach to red signals which has been around for many decades
I do find it a bit surprising that the UK relies so completely on driver mental knowledge, with no electronic or paper aids in the cab to assist, however it seems like DAS are starting to make inroads anyhow, even if they are not in a safety critical role.
As I suspected it does sound like the German network is rather more modern overall and has various key differences that make the Buchfahrplan idea more relevant than it would be in the U.K.
From time to time we see on these forums examples of drivers/guards not signing x route and this sometimes affecting the reliability of the railway, services cancelled due to shortages of trained drivers as they can't be trained fast enough, operational incidents where a driver has taken a route they don't sign etc.
So, in this modern age, could the concept of route knowledge be done away with completely in order to improve the efficiency and reliability of the railway?
When I played Train Simulator, a HUD display was provided that showed you your upcoming route in realtime including the speed limits, the gradient changes, stations approaching, signals coming up etc. If this can be done in a simulator, why can't trains be driven with an in-cab monitor that shows this information to the driver? Doing this could reduce driver/guard training times (and cost), reduce the workload of the driver, prevent mistakes, reduce instances of driver unavailability because they don't sign route x, reduce operational incidents and let any driver take any train anywhere.
Now, I'm aware train simulators aren't always realistic, and I'm not questioning the skill involved in driving trains, but what is realistically preventing this from happening when it could be such a game-changer in terms of efficiency, cost reduction and reliability?
Sometimes with route learning cab rides, all you learn is: the life story of the host driver, the host driver learns all about the route learner, general depot trash gossip, and normally finishing with a management slagging session. Once at the destination one thinks "what was the point of that".
The very expensive simulator, I used had an emergency braking rate of 16 percent g. The real traction has a rate of 12 percent g. The simulators are only used for procedure type exercises, they are no good at any dynamic realistic function. Upgrades may well have been introduced since? MS train sim would probably be better.
== Doublepost prevention - post automatically merged: ==
I think that might be more to do with power trips than psychologists! Actually at my last TOC I can remember seeing a booklet with TPWS trigger speeds at a few incident prone locations. I don’t think there was any concern that people drove differently as a result of this knowledge.
You might also want to upload a properly redacted version of that document?!
Thanks for this - really useful insight.
As I suspected it does sound like the German network is rather more modern overall and has various key differences that make the Buchfahrplan idea more relevant than it would be in the U.K.
The German safety system takes a different approach to try and avoid drivers sticking exactly to the highest possible safe speed. When passing a signal warning of an approaching red signal, the driver knows they have a certain number of seconds to slow down to a certain speed, whilst staying within a braking curve. However, the countdown of the time to reach the target speed is not revealed, nor is the current braking curve target speed.
Ultimately with ETCS you solve the problem by having multiple curves - a target curve, a warning curve, and an intervention curve, amongst others.
As mentioned driving without route knowledge is possible in Germany, and I guess in some other European countries, however this is not normal practice, there are some conditions:
The train cannot exceed 60mph
The driver must consent
The TOC must consent(they might refuse in case of a newly qualified or under investigation driver)
The line must not have any unusual features like very steep gradients
The purpose must be an unscheduled diversion or a one-off trip(e.g. delivering a unit for heavy overhaul, visit to enthusiast festival), not a regular scheduled run
Furthermore, the network has some differences which make this easier:
Extensive signage including
large reflective "mileposts" every 200 metres
countdown boards for distant signals
countdown boards for poorly visible stations
Speed-based signalling
"timetable books" giving the
maximum speed(and necessary speed adjustments for low brake effort)
locations of signals, stations, tunnels and gradients
a safety system monitoring and enforcing a safe approach to red signals which has been around for many decades
I do find it a bit surprising that the UK relies so completely on driver mental knowledge, with no electronic or paper aids in the cab to assist, however it seems like DAS are starting to make inroads anyhow, even if they are not in a safety critical role.
You're probably aware the UK uses 3 signalling appendices. These are broadly based on fully established braking performance: A = all trains nominal 6 percent g, B= normal passenger 8/9 percent g, and C= enhanced 12 percent g. These appendices are subject to 50 percent distance excess, notwithstanding derogation. With appendix A below 80 mph, the signal spacing is all over the place. Appendix C is more logical. Understanding these appendices are not part of driver training, therefore it appears signals, are placed by the actions of a shot gun. The truth is there will be some logic, including cost.
Tabled timings are meant to be set to 6 percent g at present I think? Thus from 125 mph; braking would be commenced from 1.6 miles notwithstanding build up distance. This could be 600 m plus before the first caution signal. How does a driver know what 6 percent g is in the absence of an accelerometer? At 6 percent g the consist will take just under 8 seconds to slow by 10 mph, with fully developed retarding force.
UK train driving braking strategy is all about driveability, and no theory. I believe a combination would be better, not 50-50 but say 80-20 in favour of driveability? This doctrine could reduce training costs, and definitely improve safety, absolutely no question regards the latter. ( Carstairs freight, experienced driver, 60 seconds to slow by 6 mph with full service selected, is just one such example)
Lots of question marks I appreciate, the subject is divisive.
ERTMS and double rate variable sanders, the great breakthrough is just beyond the horizon. DRVS from what I can tell have only been tested from 60 mph. The coefficient of static friction reduces at higher speed and so will airflow currents around the sander nozzle. I wonder how this fact will pan out? I guess further testing is ongoing.
AIUI those that use some form of speed-based signalling (ie the "Germanic" ones) still have it but it is much less onerous. Don't know about the others (France being the nearest!).
It’s certainly less onerous, but still very important, as could be seen recently on the first day of Lindau - Munich electric operation, when an SBB ETR 610 was routed onto the non-electrified route via Kempten at Hergatz, resulting in predictable trouble.
While obviously the signaler was primarily at fault, it was said the the (ÖBB) driver should have been able to realize his train was wrong-routed.
It’s certainly less onerous, but still very important, as could be seen recently on the first day of Lindau - Munich electric operation, when an SBB ETR 610 was routed onto the non-electrified route via Kempten at Hergatz, resulting in predictable trouble.
OK, but there were trains parked up next to ours (we were going southbound) - if not 'depot' then maybe 'sidings' or 'trainshed' but it was under cover and there were trains parked up out of us
Whether it’s a depot or sidings is a bit of a grey area, as indeed the case at a few locations on LU. But it’s not a “depot” in the true sense that maintenance happens there, the only work would be cleaning, preparation or very light casualty maintenance work.
The setup there is unique. The shed you passed through has four “roads” - 21 to 24. 21 is the northbound running line, 22 & 23 are reversing sidings, and 24 is the southbound running line. Both 21 and 24 are built and signalled to full passenger standards hence why trains pass through in service, though unusually it is also permissible to stable trains on these lines, which is unusual on LU as usually trains must not be stabled or left unattended on a running line, especially outside of terminal platforms.
That said, 2021 has given us another such example. Due to cost cutting in the form of failing to provide sidings at Battersea, Northern Line trains routinely stable overnight in the platforms at Nine Elms. Which is, of course, a problem if the train develops an issue overnight, as has happened on a few occasions.
Fundamentally the Driver either doesn't brake, brakes too late, or doesn't use enough brake. Even if you accept the position of using the correct brake force you just brake earlier and lighter.
That said, 2021 has given us another such example. Due to cost cutting in the form of failing to provide sidings at Battersea, Northern Line trains routinely stable overnight in the platforms at Nine Elms. Which is, of course, a problem if the train develops an issue overnight, as has happened on a few occasions.
Fundamentally the Driver either doesn't brake, brakes too late, or doesn't use enough brake. Even if you accept the position of using the correct brake force you just brake earlier and lighter.
Some extra theory regarding route safety systems, are surely beneficial; for example RAIB report 14/2016 Fletton Junction Peterborough appendix D. A short brief is cost effective, compared to hours of exposure training " sitting with Nellie".
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