Do we need trains that accelerate faster and brake later?

[J-2739]

The FASTECH Project in Japan produced a Shinkansen set that could stop from 320km/h in under 4000m. Indeed they had one that could do it from 360km/h but that had air brakes.

Now that would increase the capacity on HS2!

Now that's what I call I-M-P-R-E-S-I-V-E!

Now if only HS2 got something like that...

It depends on the type of train you are considering. S-Bahn trains in Germany have a high power-to-weight ratio and accelerate very well. However braking (not breaking) is much more gentle at least in the open sections. On the underground sections in central Munich braking is more similar to what one would expect on the London Underground. Swiss railways brake hard and late and my experience of the Paris suburban system is that braking techniques are more like ours. Acceleration depends on the power-to-weight ratio and it a bit dependent on the age of the stock - older trains tending not to have so much power.

German trains, like their cars, always have enough horsepower but the braking of longer distance trains is more dependent on the track layout on the approaches to the stations. Having said that continental administrations don't seem to be so concerned about SPADs...

...which may be one of the reasons why the UK railways are the safest in Europe by a country mile.

I agree with you on all those countries, from what I've seen, the Germans tend to vary in their braking distance, while the Swiss are so aggressive with their FLIRTs. I've always found the RER to look quite smooth when braking, albeit, close when braking. The other French railways are similar though.

They care about SPAD?? The level of concern may vary though, which is why we get different safety statistics for different countries.

Is there any evidence that trains are driven more aggressively in Europe or Japan?

I imagine the same considerations would apply all over the world i.e. defensive driving, leaving something in reserve in case of unexpected low adhesion etc. Things are obviously different on closed underground systems where there is much lower risk of low adhesion.

Certainly my TOC's policy is "defensive" e.g. max 20mph at 200m from a red signal, including if the signal is at the end of a platform. It's also frowned upon to regularly use brake step 3 as this leaves you with nothing in reserve apart from emergency (and in the case of a heavy train the emergency brake step won't deliver any more brake force than step 3).

There is little incentive for drivers to drive aggressively. Timetabling is so tight it's impossible to make time up and if you slip through a station or SPAD your job is at risk.

From the videos I've seen on the internet, many of the commuter trains of some of Europe (Germany) and Japan (Yamanote Line) seem to pull out aggressively out of stations (except at points) and still be at c.100km/h when arriving at a station, followed by sharper breaking to a standstill.

Other than that, I see what you mean for the rest of your post

One of the numerous things that impressed me about Japanese railways was the speed with which they enter a station they are due to stop at.

On the main commuter lines around Tokyo a 14/15 coach commuter train would generally arrive at the end of each platform at
100kmh stopping usually just short of the platform end. Thats pretty much double what most UK trains would do ('enthusiastic' drivers excepted!)

I suspect they have a form of semi automation to do this plus no issues with adhesion despite being there in autumn and on occasion in drizzly conditions. The quality of their permanent way is an eye opener.

That's always impressed me also.

They use a form of D-ATC, which I guess helps.

 

[MisterT]

Eh? The LZB is simply a cab signalling system - it gives a aim speed to the driver effectively reading signals further down the line - and doesn't have anything to do automated driving.

LZB by itself, no. But automatic train operation is possible when used in combination with AFB (Automatische Fahr- und Bremssteuerung).
On the ICE trains this is commonly used. With the advanced AFB version, the train will adjust the target speed to the maximum allowed speed (V-soll=V-max), including the braking curves and coming to a complete stop before a signal at danger.

We use the basic version of AFB in the Netherlands on the HSL-Zuid (high speed line) on the Traxx 186. Truly the basic version, so we have to set the target speed by ourselves.

 

[Skoodle]

Class 378s on London Overground are more powerful than their 377 cousins. More traction motors than on same length unit of an Electrostar. We can pull away quicker, but we don't. Why? Because it means the bodyside DOO cameras turn off sooner Slower acceleration, more time we have to ensure the platform is clear.

 

[Bletchleyite]

Class 378s on London Overground are more powerful than their 377 cousins. More traction motors than on same length unit of an Electrostar. We can pull away quicker, but we don't. Why? Because it means the bodyside DOO cameras turn off sooner Slower acceleration, more time we have to ensure the platform is clear.

That sounds like a design flaw if I ever saw one

 

[edwin_m]

Modern EMUs only accelerate hard up to around 50mph after that they start the acceleration peters off considerably as they are geared for low acceleration. Can take them a considerable amount of time to reach v-max.

Three phase motors as used on EMUs from the Networker onwards are much better at sustaining acceleration at higher speeds. Or at least they are if not limited by traction current restrictions, which as mentioned are needed for modern units on the third rail to avoid overloading the supply. In the older DC motors acceleration intrinsically falls off at higher speeds, and although field weakening gives a speed boost it is at the expense of lower torque.

Hence trains with AC drives are usually not geared for the line speed of a particular route. The old 310 and 312 units came in a 75mph version which mainly ran on the (then) 75mph WCML slow lines, and a 90mph version used on other routes where it shared tracks with faster trains. The 357 with AC motors is rated at 100mph but never exceeds 75mph on its normal operating route (unless it's been upgraded recently).

 

[HSTEd]

Now that's what I call I-M-P-R-E-S-I-V-E!

Now if only HS2 got something like that...

It cuts the headway from 130 seconds to something like 80 seconds. So operational headway from something like 150 seconds to 100 seconds.

If you plug that into the same assumptions that gave ~18 trains per hour operationally (in terms of using only ~75% of theoretical paths) then the capacity jumps to something like ~27 trains per hour.

Which rather drastically reduces the capital cost of the seats.

 

[Class 170101]

From the videos I've seen on the internet, many of the commuter trains of some of Europe (Germany) and Japan (Yamanote Line) seem to pull out aggressively out of stations (except at points) and still be at c.100km/h when arriving at a station, followed by sharper breaking to a standstill.

The 357 with AC motors is rated at 100mph but never exceeds 75mph on its normal operating route (unless it's been upgraded recently).

The 357s when introduced initially used the Class 312 schedules. Later some train schedules, particularly in the peak, were upgraded to Class 357 schedules however it could be a struggle to keep time with them. Drivers said it was possible but you would be hitting the platform ramp at c.40mph to a stand and accelerating away very hard, very uncomfortable for passengers. The Class 357 schedules I believe are now more realistic these days with appropriate dwell times. Maximum speed of the route is still 75mph as far as I am aware though there have been many schemes over the years to raise linespeeds upto 100mph.

 

[Class 170101]

There is certainly an argument that SRTs that were achievable in the past are either tight or impossible now based on defensive driving policies. Operators then refuse to increase to reflect actual running. Double edged sword.

Problem is unfortunately on certain routes it loses them money as journey times would get longer on paper, as well as in practise, when compared with the competition.

 

[The Growl]

I've seen trains like that in other countries. While they do shift a little, they don't show particular discomfort.

I'd say because the shinkansens have standard (green) class seats that look as if they cost £100 a piece. The Gran (first first) class is even better.

 

[theageofthetra]

Class 378s on London Overground are more powerful than their 377 cousins. More traction motors than on same length unit of an Electrostar. We can pull away quicker, but we don't. Why? Because it means the bodyside DOO cameras turn off sooner Slower acceleration, more time we have to ensure the platform is clear.

Have I read that right- you look at the in cab monitor once the train is on the move not the road ahead?

 

[philthetube]

In my opinion it actually does - the drivers just very rarely make use of it. On some very rare occasions you do get to experience that the acceleration power is there, but very seldom is it ever used to that extent. I'm rather hoping that when the surface routes go ATO (coupled with the 750V changeover which I assume is still happening?) there'll be a Jubilee-like step change in performance.As it stands now I expect the S stock to be capable of a good 20% reduction in between-station journey times.

Drivers on S stock do tend to use full power when accelerating, they will become quicker when ATO is introduced. However at the same time braking will probably become gentler in outside sections.

Comparisons between S stock and 96 stock are interesting to watch. Northbound if the 2 stocks depart at the same time the back of the 96 will reach the front of the S before it needs to start braking, however southbound 96 stock approaches the platform much more slowly than S stock, (on average as S stock braking depends on the driver).

 

[WideRanger]

From the videos I've seen on the internet, many of the commuter trains of some of Europe (Germany) and Japan (Yamanote Line) seem to pull out aggressively out of stations (except at points) and still be at c.100km/h when arriving at a station, followed by sharper breaking to a standstill.

Other than that, I see what you mean for the rest of your post



That's always impressed me also.

They use a form of D-ATC, which I guess helps.

Different lines can be quite different to each other. I have found that most of the JR lines (including the Yamonote) are relatively conservative in the way they accelerate and brake. But contrast that with some of the private lines such as the Keikyu in Tokyo or the Hankyu in Osaka. Those trains really get a shift on.

 

[WideRanger]

I'd say because the shinkansens have standard (green) class seats that look as if they cost £100 a piece. The Gran (first first) class is even better.

Green class is equivalent to First class. Gran Class is 'super-luxury'. The standard class doesn't have a special designation. Seats in Standard class are pretty variable. Not great on local and commuter trains (largely longitudinal seating, even for long journeys). Some of the old intercity trains on conventional lines (largely phased out but sometimes used on extra or seasonal services) can be a bit cramped. But on modern intercity and regional trains (including shinkansen) the seats are generally much better than UK first class, with huge seat pitch, large degree of recline, and seats rotatable so passengers can choose to use them airline or facing. They are often 3+2, but the train is much wider so it doesn't feel cramped. The big exception is the double deck communter shinkansen trains which have absolutely terrible 3+3 seating. Fortunately they are on the way out.

 

[317666]

The culture in Germany and Switzerland seems to be to drive hard (but within speed limits) to make up for lost time. In Switzerland especially it's not uncommon to see longer trains hit the platform at 40-50mph, but still come to a smooth stop.

 

[HLE]

General rule of thumb for me is 30 at the platform ramp if the signal is off. 20 at the AWS if not. 15 if it's a terminating platform. Subject to any lower limits being in place of course.
Any station stops I do I want to do as smoothly and fuss free as possible as you are always aware that people will probably be up on their feet collecting luggage and such like. Any higher and it would mean an aggressive stop which could easily knock people off balance.
For me I take pride in delivering a smooth ride for my adoring public and because of that I drive defensively and do not take risks. Even if I am late I don't drive any different as that is when things can go wrong. I know some drivers won't have that attitude and will do things their way but thats up to them. It's their record.
Of course this time of year its even more important to be careful when braking and always have a little held back just in case.
Voyager brakes in the dry are very good and it's good to know if you have to stop quick you can. When we were doing Voyager handling before introduction we were encouraged to do sharp stops to get the feel of the limits of braking. I remember coming into Banbury on the up and hitting the platform ramp at 70 and stopping fully on the platform with a full brake application. Definitely not recommended with people on!!

Woah that's impressive although a 350 hitting the ramp at 40/50mph at some stations is a common occurrence, different driving styles excepted of course.

If you tried hitting the ramp at 30 on a 153 even in full service, you'd end up closer to the next station!

 

[Bromley boy]

Have I read that right- you look at the in cab monitor once the train is on the move not the road ahead?

That doesn't seem unreasonable at all.

At my TOC (external platform monitors) the procedure is to check monitors clear, check the signal and then look at the monitors for the couple of seconds or so they remain visible as you pull away. This is the most dangerous time as someone may run up to the train, jab at a button and slip underneath. It's also a last chance to see someone trapped you missed previously. For this reason I'm glad I don't personally have to work with in-cab monitors that shut off immediately.

Of course there is usually no option to do this when the platform/monitors are offside as you will have to cross the cab back to the driver's desk and the monitors are usually mounted too high to remain visible. Therefore safety is somewhat degraded at these locations in the seconds between your final check of the monitors, crossing the cab and taking power.

 

[Bromley boy]

There is certainly an argument that SRTs that were achievable in the past are either tight or impossible now based on defensive driving policies. Operators then refuse to increase to reflect actual running. Double edged sword.

That's an interesting point.

Timetabling seems a bit of a black art. We have routes where it's virtually impossible to keep time. Whether this is because timings were set when aggressive driving was more common, I don't know.

Equally we have other routes where the timings seem almost too generous.

 

[edwin_m]

There's an interesting debate to be had about whether the driver should be watching the line ahead as the train leaves, or follow the Underground practice of watching the platform-train interface until the train has left the platform. I understand Underground lines with cab monitors keep them working as the train leaves the platform.

 

[Bromley boy]

There's an interesting debate to be had about whether the driver should be watching the line ahead as the train leaves, or follow the Underground practice of watching the platform-train interface until the train has left the platform. I understand Underground lines with cab monitors keep them working as the train leaves the platform.

The only benefit looking ahead in those first few seconds would be to react to the starting signal going back on you (remember you've already checked the signal is showing a proceed aspect before turning back to the monitors). It's far more likely something of risk is going to happen behind you on the platform than ahead of you.

Of course it's not ideal but I suspect most drivers would rather suffer a technical spad than trap and drag someone!

Unfortunately you only have one set of eyes and can't look in two places at once. You have to mitigate risk as best you as can. This is the compromise inherent in DOO driver-performed dispatch in situations with no bat and flag and no CD/RA.

 

[The Growl]

Green class is equivalent to First class. Gran Class is 'super-luxury'. The standard class doesn't have a special designation. Seats in Standard class are pretty variable. Not great on local and commuter trains (largely longitudinal seating, even for long journeys). Some of the old intercity trains on conventional lines (largely phased out but sometimes used on extra or seasonal services) can be a bit cramped. But on modern intercity and regional trains (including shinkansen) the seats are generally much better than UK first class, with huge seat pitch, large degree of recline, and seats rotatable so passengers can choose to use them airline or facing. They are often 3+2, but the train is much wider so it doesn't feel cramped. The big exception is the double deck communter shinkansen trains which have absolutely terrible 3+3 seating. Fortunately they are on the way out.

Yes got Green and Standard mixed up . I've heard about those double deck ones. 3+3 sounds horrific.

 

[Mordac]

Woah that's impressive although a 350 hitting the ramp at 40/50mph at some stations is a common occurrence, different driving styles excepted of course.

If you tried hitting the ramp at 30 on a 153 even in full service, you'd end up closer to the next station!

Maybe that's why I once had one overshoot the platform at Oxenholme!

 

[The Growl]

Maybe that's why I once had one overshoot the platform at Oxenholme!

Naughty naughty!

 

[Fincra5]

377's will brake hard and fast in step 3.. but the company line at the TOC is to not to use step 3 in normal braking as there's only emergency left... oh and it wears more on brake pads which = £££s

 

[The Growl]

377's will brake hard and fast in step 3.. but the company line at the TOC is to not to use step 3 in normal braking as there's only emergency left... oh and it wears more on brake pads which = £££s

Which means that everytime a shinkansen pulls in, the wheels are slowly destroyed? Unless I'm wrong in which case, you should correct me!

 

[J-2739]

Which means that everytime a shinkansen pulls in, the wheels are slowly destroyed? Unless I'm wrong in which case, you should correct me!

Yeah, just a little wear and tear which builds up. After a while, they need replacement equipment which costs some cents.

Obviously, the faster it is, the more replacements needed, which costs, you know...

Extra kaching!

 

[The Growl]

Yeah, just a little wear and tear which builds up. After a while, they need replacement equipment which costs some cents.

Obviously, the faster it is, the more replacements needed, which costs, you know...

Extra kaching!

Wow, no wonder drivers aren't ever allowed into step 3. They'd have to pay a little more!

 

[philthetube]

The only benefit looking ahead in those first few seconds would be to react to the starting signal going back on you (remember you've already checked the signal is showing a proceed aspect before turning back to the monitors). It's far more likely something of risk is going to happen behind you on the platform than ahead of you.

Of course it's not ideal but I suspect most drivers would rather suffer a technical spad than trap and drag someone!

Unfortunately you only have one set of eyes and can't look in two places at once. You have to mitigate risk as best you as can. This is the compromise inherent in DOO driver-performed dispatch in situations with no bat and flag and no CD/RA.

A big difference here is the difference in spad policy between network rail, (who I think make the rules on this) and LUL. As I understand it on the main line it is basically three sapds and you are out. On the underground it is four in a rolling 2 years. Spads do increase both with DOO and again with in cab monitors (LUL admit this) but because of different policies the unions are less concerned.

 

[superkev]

A lot of metros and some lu lines are automated in that the driver normally operates the doors which I believe is quicker than manual driving.
I've often wondered how the computers cope with leaves etc. Do they have a choice of settings depending on season or weather?
K

 

[Lrd]

A lot of metros and some lu lines are automated in that the driver normally operates the doors which I believe is quicker than manual driving.
I've often wondered how the computers cope with leaves etc. Do they have a choice of settings depending on season or weather?
K

The powers that be can reduce the profiles for braking and accelerating so they can set it to accelerate slower or brake earlier and gentler.

Or the most common scenario is that the computers get lost as they can't count the wheel revolutions, apply the emergency brake and make the driver take over.

 

[rebmcr]

A big difference here is the difference in spad policy between network rail, (who I think make the rules on this) and LUL. As I understand it on the main line it is basically three sapds and you are out. On the underground it is four in a rolling 2 years. Spads do increase both with DOO and again with in cab monitors (LUL admit this) but because of different policies the unions are less concerned.

Also on LU, trainstop equipment mitigates a decent proportion of the risk from events after a SPAD.