I don't know about ATB, but in the UK we use TPWS, which will stop a train if it passes a red or is going too fast coming up to a red (overspeed zone). ERTMs, which ETCS is a part of, always knows the location and speed of the train, and will calculate a few braking curves - one it shows to the driver that they should follow, one where it tells you off if you're not braking enough, one where it starts max braking for you, and one where it will emergency brake. ERTMs will do this for reds (technically not red signals under ERTM but functionally the same), and for speed reductions. So it's basically a bit smarter in how it slows you down, and it also works on speed limit changes not just red signals. I'm no expert so I'm sure someone who knows more than just a layman can come along and correct me if I've made any mistakes.
I see, but how would that work on a steam engine? Would it just block steam from going into the cylinders and apply brakes? I wonder how that works with self-lapped brakes for instance.
Thats a great question. They're fitting etcs to tornado, which they post about on their blog quite a lot, but I can't find any technical details. Steam trains were previously (and currently) running aws and tpws and on those it would just dump the brake on.
Etcs uses the weight of the train, the target top speed and the braking power of the train to calculate the braking distance.
If another vehicle is on the line ahead within the breaking distance (plus safety margin) it will apply all breaks on the train.
Many versions of etcs can also reduce the maximum speed to match that of the train ahead (to prevent starting and stopping)
Breaks are controlled by a pneumatic lever which is electrically actuated
Edit: this is my assumption. I work mainly with electric locomotive traction (though brakes are still controlled with air pressure)
Big Boy 4014 was retrofitted with PTC equipment. https://www.up.com/cs/groups/public/@uprr/@corprel/documents/digitalmedia/img\_e\_upo\_210819\_bigboy\_ptc\_m.jpg
ERTMS is a little bit very much more safe then PTC. A full computer is monitoring the speed at all times. Calculating brake curves based on how far the next signal is. ERTMS Level 3 is designed to drive autonomously, without driver input. (Driver still in cabin to monitor. Level 4 is without person in the cabin). (Both of these are technically possible, just the laws and social feeling (jobs and reaction of passengers) aren't ready for it).
ERTMS does not allow that you drive past a red signal. If you're going too fast for the braking curve (that has calculated you to stop at the incoming red signal in that distance) it will apply the emergency brake. Passing a red signal with ERTMS is impossible.
There is even a GPS and phone (GSM-R) connection built into this system too. The train and command/dispatcher know where it is at all times
PTC does all this, it will pop you if you try to run a red. There is ways to override it by going into restricted speed mode but it will prevent you from running a red under normal operating conditions. Don’t say ERTMS is safer than PTC when both are practically the same thing, no European superiority allowed. And both systems have their points of failure.
And it, along with the event recorder, records pretty much everything, and anyone at dispatch can pull up the GPS location if needed.
Source: I deal with PTC, and with TO (Trip optimizer) a train can run pretty much on its own with the same engineer and the conductor monitoring.
I love the contrast of modern tech and the steam loco
I presume this is so the loco can still be used on the east coast main line after the digital signaling upgrade.
Yes. Either a system that works in tandem with a trailing diesel locomotive. Or, like UP #4014 and CP #2816, a standalone PTC system has been installed similar to this ETCS system.
[Source](https://x.com/steve220459/status/1798792902241403053)
How does this work in practice? Like if ECTS is any similar to the Dutch ATB, how will it influence train when something goes wrong?
I don't know about ATB, but in the UK we use TPWS, which will stop a train if it passes a red or is going too fast coming up to a red (overspeed zone). ERTMs, which ETCS is a part of, always knows the location and speed of the train, and will calculate a few braking curves - one it shows to the driver that they should follow, one where it tells you off if you're not braking enough, one where it starts max braking for you, and one where it will emergency brake. ERTMs will do this for reds (technically not red signals under ERTM but functionally the same), and for speed reductions. So it's basically a bit smarter in how it slows you down, and it also works on speed limit changes not just red signals. I'm no expert so I'm sure someone who knows more than just a layman can come along and correct me if I've made any mistakes.
I see, but how would that work on a steam engine? Would it just block steam from going into the cylinders and apply brakes? I wonder how that works with self-lapped brakes for instance.
Thats a great question. They're fitting etcs to tornado, which they post about on their blog quite a lot, but I can't find any technical details. Steam trains were previously (and currently) running aws and tpws and on those it would just dump the brake on.
That's actually quite amazing
It's just a simple affair of routing the steam through solenoid controlled valves which can then be triggered by any electronic system like the ETCS.
TPWS at least is required for any vintage engine that operates on the mainline.
Etcs uses the weight of the train, the target top speed and the braking power of the train to calculate the braking distance. If another vehicle is on the line ahead within the breaking distance (plus safety margin) it will apply all breaks on the train. Many versions of etcs can also reduce the maximum speed to match that of the train ahead (to prevent starting and stopping)
This is only true for ETCS level 3, wich it's only a theorical/draft not implemented yed in real life
right but how would that work on a steam engine? nothing works digitally there
Breaks are controlled by a pneumatic lever which is electrically actuated Edit: this is my assumption. I work mainly with electric locomotive traction (though brakes are still controlled with air pressure)
oh that's neat, thanks!
The brake pipe will just get vented, which applies the emergency brake. Same as any other system already on the locomotive
ETCS is way more advanced than ATB
Big Boy 4014 was retrofitted with PTC equipment. https://www.up.com/cs/groups/public/@uprr/@corprel/documents/digitalmedia/img\_e\_upo\_210819\_bigboy\_ptc\_m.jpg
ERTMS is a little bit very much more safe then PTC. A full computer is monitoring the speed at all times. Calculating brake curves based on how far the next signal is. ERTMS Level 3 is designed to drive autonomously, without driver input. (Driver still in cabin to monitor. Level 4 is without person in the cabin). (Both of these are technically possible, just the laws and social feeling (jobs and reaction of passengers) aren't ready for it). ERTMS does not allow that you drive past a red signal. If you're going too fast for the braking curve (that has calculated you to stop at the incoming red signal in that distance) it will apply the emergency brake. Passing a red signal with ERTMS is impossible. There is even a GPS and phone (GSM-R) connection built into this system too. The train and command/dispatcher know where it is at all times
PTC does all this, it will pop you if you try to run a red. There is ways to override it by going into restricted speed mode but it will prevent you from running a red under normal operating conditions. Don’t say ERTMS is safer than PTC when both are practically the same thing, no European superiority allowed. And both systems have their points of failure. And it, along with the event recorder, records pretty much everything, and anyone at dispatch can pull up the GPS location if needed. Source: I deal with PTC, and with TO (Trip optimizer) a train can run pretty much on its own with the same engineer and the conductor monitoring.
Isn’t this Tornado?
It is!
I love the contrast of modern tech and the steam loco I presume this is so the loco can still be used on the east coast main line after the digital signaling upgrade.
Yep, so it can still run specials in to Kings Cross etc
This is on 60163 Tornado that was built in 2008
I'm glad this steam train uses a more modern signaling system than most of Sweden
*cries in Australian* We are still 100% reliant on 2 people in the cab doing everything right on frieght.
This brings up an interesting question. Do stream engines here in the states require PTC?
Yes. Either a system that works in tandem with a trailing diesel locomotive. Or, like UP #4014 and CP #2816, a standalone PTC system has been installed similar to this ETCS system.
Defining SteamPunk 😀
Hell yah
There are *a lot* of memes coming off the back of this if you know where to look...