Do we need trains that accelerate faster and brake later?

[bahnause]

In Switzerland especially it's not uncommon to see longer trains hit the platform at 40-50mph, but still come to a smooth stop.

The rule of thumb for the first and second generation double decker trains in and around the Zürich area is

• 50-60km/h (30-35mph) for a 100m train
• 70km/h (45mph) for a 200m train
• 80-90km/h (50-55mph) for a 300m train

at the beginning of the platform. That allows to come to a stop using the regenerative brake exclusively in good conditions. There is still plenty of margin left using this rule. As there are no "brake steps", so controlling the brake force is easy and smooth. Magnetic friction brakes are available, but are only used in emergency conditions.

Approaching a singal at danger ist a different story though...

Acceleration ist really impressive, especially with the newest generation of trains. But it does come with wear and tear on the wheels and the tracks.

 

[richieb1971]

As I understood it, the ability to accelerate faster and brake later was a deployment idea to facilitate faster running times on UK bendy tracks. Since if you have to slow down for a corner, the quicker you get back up to speed. And also the spacing and frequency between station stops.

In Japan and Europe, there are not many bendy tracks that you would need to slow down and trains stop less often due to lesser amount of stations. So that makes it (for the most part) quite cost effective, because your only using the practice at the beginning and at the end of your journeys and seldom in between.

In the UK, there would be interim times of the journey when slowing down and speeding up. So it would wear out your mechanical parts quite a lot quicker.

 

[coppercapped]

As I understood it, the ability to accelerate faster and brake later was a deployment idea to facilitate faster running times on UK bendy tracks. Since if you have to slow down for a corner, the quicker you get back up to speed. And also the spacing and frequency between station stops.

In Japan and Europe, there are not many bendy tracks that you would need to slow down and trains stop less often due to lesser amount of stations. So that makes it (for the most part) quite cost effective, because your only using the practice at the beginning and at the end of your journeys and seldom in between.

In the UK, there would be interim times of the journey when slowing down and speeding up. So it would wear out your mechanical parts quite a lot quicker.

Err...have you ever travelled much in Belgium, The Netherlands or Germany? The new high speed lines are well aligned and don't have many stations...

 

[richieb1971]

Err...have you ever travelled much in Belgium, The Netherlands or Germany? The new high speed lines are well aligned and don't have many stations...

Yes, thats exactly what I am saying.

 

[WideRanger]

As I understood it, the ability to accelerate faster and brake later was a deployment idea to facilitate faster running times on UK bendy tracks. Since if you have to slow down for a corner, the quicker you get back up to speed. And also the spacing and frequency between station stops.

In Japan and Europe, there are not many bendy tracks that you would need to slow down and trains stop less often due to lesser amount of stations. So that makes it (for the most part) quite cost effective, because your only using the practice at the beginning and at the end of your journeys and seldom in between.

In the UK, there would be interim times of the journey when slowing down and speeding up. So it would wear out your mechanical parts quite a lot quicker.

Japan, being a predominantly mountainous country has very bendy track for most of its non-Shinkansen routes outside of the cities. It is the same reason why it uses narrow gauge. And on many routes, there are stations every couple of kilometres (The Yamanote Line has 29 stations on a 35km loop). That's why the difference in journey speed between the traditional routes and Shinkansen routes are so great.

 

[Sean Emmett]

My experience of timing trains on the Waterloo to Reading line is that Desiros and Junipers are certainly quicker off the mark and sharper at braking than the CIGs/VEPs, but overall journey times are worse than the 1980s.
- Level crossings at Rusham and Star Lane converted from AHB to CCTV full barrier for safety reasons
- so even more signal checks from tardy closing of barriers
- ages to release doors when stopped
- More passengers. Lots more.
- So station stops in the peaks of over 2 minutes at Twickers, Richmond and Clapham Jn not uncommon.
- The shortest station stop with a Desiro (Longcross) takes at least 30 sec. It was rather less with the slammers!
- OTR means strict observance of speed limits. Line limit is 70 but the slammers got into the 80s on the faster services. More significant is the 20 mph from Staines over the Thames now strictly adhered to.
- no fast trains any more. My semi regular 07.26 from Ascot to Waterloo takes an hour most days.

Not sure what the new limits will be on the crossovers outside P 20-24 at Waterloo? Hopefully at least 25 mph?

Power supply enhancement may help and timings are supposed to be trimmed accordingly but all that energy and effort to save a few seconds running is wasted waiting for the door release.

Time to release doors, allow folk off and on, then close, secure and away will be the limiting factor for trains per hour throughput on busy sections.

 

[LNW-GW Joint]

I use the class 507/8 trains a lot on Merseyrail.
Like all PEP units they have good doors and fast dwell times, and they move off smartly.
But they stop incredibly slowly, and I presume this is due to the antiquated brakes rather than driving technique.
There's also a lot of squeal from the wheels.
The new Stadlers should revolutionise things, as long as the doors don't have a "Desiro" long release mechanism.

 

[317666]

As there are no "brake steps", so controlling the brake force is easy and smooth.

This. A three-step brake where you're not even supposed to use the third step surely can't give you much flexibility?

 

[najaB]

This. A three-step brake where you're not even supposed to use the third step surely can't give you much flexibility?

Do you drive? If so, do you drive such that you *regularly* have to push the brake pedal to the floor with all your force?

 

[317666]

Do you drive? If so, do you drive such that you *regularly* have to push the brake pedal to the floor with all your force?

No I don't, but I'm not suggesting that either. What I am suggesting, from an outsider's point of view, is that more brake steps (and I don't mean stronger ones, but more between the current 1 and 3) or continuous brakes can allow faster arrivals into stations without it being uncomfortable for the passenger - which as bahnause says is witnessed in Switzerland on a daily basis.

 

[najaB]

No I don't, but I'm not suggesting that either. What I am suggesting, from an outsider's point of view, is that more brake steps (and I don't mean stronger ones, but more between the current 1 and 3) or continuous brakes can allow faster arrivals into stations without it being uncomfortable for the passenger - which as bahnause says is witnessed in Switzerland on a daily basis.

I don't drive a train, but from this thread it's far from clear that additional brake steps would necessarily translate into faster arrivals. The comments posted by drivers lead me to understand that the braking system isn't the limiting factor but rather defensive driving techniques - why approach at a high speed and brake hard if you don't have to?

 

[317666]

I don't drive a train, but from this thread it's far from clear that additional brake steps would necessarily translate into faster arrivals. The comments posted by drivers lead me to understand that the braking system isn't the limiting factor but rather defensive driving techniques - why approach at a high speed and brake hard if you don't have to?

Someone correct me if I'm wrong by all means, but the impression I was under was that the use of Step 3 is frowned upon so that a driver always has more brake force available if needed without having to use emergency brakes. If, for instance, there was another step between 2 and 3, it would allow for more brake force to be used whilst still having a non-emergency step available if needed.

Why approach at high speed and brake hard? On a late-running commuter train with lots of stops, if a few seconds can be saved at each stop by braking harder and later, then it could potentially add up to a minute or two being made up, and make the difference between a train being officially on time or late.

 

[Skoodle]

For me it's more about safety and comfort. Sure, I could confidently brake harder and lighter more often, but it's just not practical. It is more mentally draining to be "on the edge" all the time. Why put yourself through that? Stress levels go up, tunnel vision starts creeping in and that's when things go wrong and incidents happen. Believe me it's much easier to come in nice and calmly, focusing on the correct stop board, giving you time to look out for any hazards that may affect your train on the track or platform.

If you're constantly braking later and harder the only thing you'll be focusing on is the end of the platform and that's it! This may shock most of you, but being on time is pretty much the last thing on our minds. Regardless of whether I'm late or early, I will always brake the same (unless weather conditions make me adjust accordingly). The only place I will "make up" time, is if I have clear signals and can take it up to line speed where I normally usually don't. Even then I'll start braking a bit earlier so that I am at the same braking area at my usual speed. It doesn't really achieve much though, unless you have a clear run from one end of the line to the other and no passengers.

Instead of focusing on train acceleration and braking to reduce delays, we need better education to passengers. Namely that there usually is more than one door on a train and unless you're the first couple of people, trying to get off through the doors closest to the exit will make you be one of the last to leave the train!!

 

[najaB]

Why approach at high speed and brake hard? On a late-running commuter train with lots of stops, if a few seconds can be saved at each stop by braking harder and later, then it could potentially add up to a minute or two being made up, and make the difference between a train being officially on time or late.

Personally, as a passenger, I would rather my driver concentrated on getting me there safely, and damn the timetable!

 

[SpacePhoenix]

[youtube]ca2lGLI_ICs[/youtube]

It doesn't always save time

 

[bahnause]

For me it's more about safety and comfort. Sure, I could confidently brake harder and lighter more often, but it's just not practical. It is more mentally draining to be "on the edge" all the time.

I very rarely drive "on the edge", even at peak times with a delayed train I leave myself enough margin for errors properly. But I do brake harder and later. We are trained to do so and learnt how to do it. It isn't even uncomfortable for the passengers. The speeds I posted above are a rather defensive approach (but very helpful for "drivers in the make").

 

[The Growl]

[youtube]https://youtu.be/6K3MQ_hn6XY[/youtube]

Found this a while ago, and remembered it now. Apparently energy conservation is a lot to do with slower accelaration and braking. Makes sense to me.

 

[Bromley boy]

Someone correct me if I'm wrong by all means, but the impression I was under was that the use of Step 3 is frowned upon so that a driver always has more brake force available if needed without having to use emergency brakes. If, for instance, there was another step between 2 and 3, it would allow for more brake force to be used whilst still having a non-emergency step available if needed.

Why approach at high speed and brake hard? On a late-running commuter train with lots of stops, if a few seconds can be saved at each stop by braking harder and later, then it could potentially add up to a minute or two being made up, and make the difference between a train being officially on time or late.

However maximum braking saving a few seconds per stop per journey would soon be offset once a couple of station slip-throughs took place, with all the ensuing delays.

To clarify my previous comment, according to our driving policy, It's fine to use step 3 when necessary, just not to rely on it. I use it frequently to catch the monitors if I've slightly over-egged the approach speed. If I were downloaded and found to be hitting every platform at 50mph and whacking it into step 3 to stay on the platform, that would be frowned upon. Different units have different braking characteristics so what works in one won't work in another, risk of unexpected low adhesion etc.

It's worth pointing out again the way the 3 step braking system works. The air suspension measures the weight of the train and moderates the brake force such that the braking performance delivered in each step is always consistent. With a heavy train, step 3 will deliver the same (maximum) brake force as emergency. Therefore if you always use step 3 you aren't leaving anything in reserve.

Hard braking works fine on enclosed systems e.g. Victoria line acceleration/braking is a wonder to behold. However I understand even ATO tube lines with outdoor sections are "dialled down" during leaf fall to deliver gentler braking to minimise risk of starion run-throughs.

 

[samuelmorris]

I use the class 507/8 trains a lot on Merseyrail.
Like all PEP units they have good doors and fast dwell times, and they move off smartly.
But they stop incredibly slowly, and I presume this is due to the antiquated brakes rather than driving technique.
There's also a lot of squeal from the wheels.
The new Stadlers should revolutionise things, as long as the doors don't have a "Desiro" long release mechanism.

I'm fairly confident this is a guards panel issue. The door release on AGA 360s in the DOO section is pretty swift, on SWT comparatively it takes forever...

 

[Mintona]

From what I understand, train drivers are soon to be responsible for passengers on a platform before the train has stopped. That's to say, if somebody was to fall (or jump) in front of a train and be hit as it was slowing down to stop, the driver would be responsible for not driving the train at a speed that he could stop on sight and prevent the incident.

So I imagine station approaches will soon be slowing down considerably.

 

[najaB]

From what I understand, train drivers are soon to be responsible for passengers on a platform before the train has stopped.

That is an interesting development. Could I ask where you heard this?

So I imagine station approaches will soon be slowing down considerably.

And the rest! There goes the timetable on busier routes.

 

[Mintona]

That is an interesting development. Could I ask where you heard this?

And the rest! There goes the timetable on busier routes.

It's come from a drivers' safety brief.

 

[J-2739]

From what I understand, train drivers are soon to be responsible for passengers on a platform before the train has stopped. That's to say, if somebody was to fall (or jump) in front of a train and be hit as it was slowing down to stop, the driver would be responsible for not driving the train at a speed that he could stop on sight and prevent the incident.

So I imagine station approaches will soon be slowing down considerably.

I was wondering, couldn't the horn be sounded off before entering the platform to alert the other passengers that a train is approaching?

I got this idea from the railways in Japan.

 

[najaB]

I was wondering, couldn't the horn be sounded off before entering the platform to alert the other passengers that a train is approaching?

I got this idea from the railways in Japan.

Doesn't really help if someone gets pushed/tripped and even less useful if it is someone trying to commit suicide.

 

[SpacePhoenix]

I'm fairly confident this is a guards panel issue. The door release on AGA 360s in the DOO section is pretty swift, on SWT comparatively it takes forever...

Proably to do with the guard opening their local door, checking the train is in the platform and then releasing the rest of the doors on that side

 

[WideRanger]

I was wondering, couldn't the horn be sounded off before entering the platform to alert the other passengers that a train is approaching?

I got this idea from the railways in Japan.

Drivers in Japan only do this if there is someone standing or walking over the yellow line (normally about 50 cm from the platform edge) as they approach.

 

[The Growl]

From what I understand, train drivers are soon to be responsible for passengers on a platform before the train has stopped. That's to say, if somebody was to fall (or jump) in front of a train and be hit as it was slowing down to stop, the driver would be responsible for not driving the train at a speed that he could stop on sight and prevent the incident.

So I imagine station approaches will soon be slowing down considerably.

Wow, the rail industry's not becoming funner, or more easy to get into.

 

[Chris125]

[youtube]https://youtu.be/6K3MQ_hn6XY[/youtube]

Found this a while ago, and remembered it now. Apparently energy conservation is a lot to do with slower accelaration and braking. Makes sense to me.

Incidentally it seems that to make youtube inbeds work you must only use the letters at the end, not the full url - in this case 6K3MQ_hn6XY

[youtube]6K3MQ_hn6XY[/youtube]

 

[theageofthetra]

I was wondering, couldn't the horn be sounded off before entering the platform to alert the other passengers that a train is approaching?

I got this idea from the railways in Japan.

There is an alarm and an announcement when a train approaches. I only heard a horn on the busiest stations if the platform was really crowded, particularly at Kawasaki where it is narrow near the stairs.
--- old post above --- --- new post below ---

Wow, the rail industry's not becoming funner, or more easy to get into.

Has your union briefed you on this? Seems completely unacceptable and unworkable.

 

[crazystripe]

From what I understand, train drivers are soon to be responsible for passengers on a platform before the train has stopped. That's to say, if somebody was to fall (or jump) in front of a train and be hit as it was slowing down to stop, the driver would be responsible for not driving the train at a speed that he could stop on sight and prevent the incident.

So I imagine station approaches will soon be slowing down considerably.

This would be hugely frustrating. It's already annoying that some drivers are so much more over-cautious than others, with the worst offenders easily losing 5 minutes versus the timetable in a sequence of 4-5 station stops.