Seven-step brake and braking from 125mph.

[hexagon789]

We've had a recent thread on the 3-step brake and driving techniques for that, but wondered about braking with the seven-step (Release, Initial, 2, 3, 4, 5, Full Service, Emergency) system as fitted to HSTs, Mk3 DVTs, InterCity 225s and I think also Pendolinos?

Essentially I'd be interested to know what the initial application is - I would've thought Step 4 or maybe 3. Also, how hard do you have to brake for a red when doing 125mph?

Some of the signal spacing on the ECML and WCML looks to be only about 1.7-1.8 miles from Double Yellow to Red, which you me suggests a need for Step 4 braking (6%g retardation) most of the way.

Perhaps a rather more specialised question, but these things interest and intrigue me!

 

[irish_rail]

If braking for stations start with step 1 as this prevents the brake burning smells entering the coaches. After about 5 seconds into step 2 or greater ...
If doing 125 and seeing an adverse signal will usually go straight to 3 or 4 to get the speed down. Although different HST sets have different standards of brake so depends much on the individual set...

 

[hexagon789]

If braking for stations start with step 1 as this prevents the brake burning smells entering the coaches. After about 5 seconds into step 2 or greater ...
If doing 125 and seeing an adverse signal will usually go straight to 3 or 4 to get the speed down. Although different HST sets have different standards of brake so depends much on the individual set...

Thank you very much! Exactly the detail I was looking for.

So Steps 5 and 6 are not routinely used then? Or rather only for 'correcting' retardation as with Step 3 on 3-step traction?

 

[irish_rail]

5 and 6 tend to be if you have a bad brake and need it but generally most drivers try to avoid the higher steps of possible, though there are drivers who go straight to 5 or 6 when seeing a double yellow at 125 , personally I think that overkill.

 

[hexagon789]

5 and 6 tend to be if you have a bad brake and need it but generally most drivers try to avoid the higher steps of possible, though there are drivers who go straight to 5 or 6 when seeing a double yellow at 125 , personally I think that overkill.

I asked because my general impression is that with modern defensive driving techniques, the use of higher braking for normal running seems to be frowned on.

Certainly liberal use of Step 3 with a 3-step brake doesn't seem to be favoured, so I wondered if the same applied to the seven-step brake.

Are HST brakes are really variable then?

 

[PudseyBearHST]

On a class 390, usually step 2/3 (max 4) for a regular station stop.

When doing 125 and braking for a red, there are so many factors to consider. Obviously route knowledge will help determine how heavy the brakes need to be initially applied. There are 3 state banner repeaters as well at certain locations to help avoid heavy braking and give you extra braking distance as you can see if you have a double yellow from further away as some sections are extremely short. You also have to consider TPWS as some areas the TPWS is very ‘sensitive.’
Generally speaking, step 3/4 is a good brake application to make for double yellows. Step 2/3 if you are on a long straight and can see double yellows a few sections away.
It will also come down to the specific driver as Irish Rail said. Some drivers will use step 5/6 immediately when they see any adverse aspects while a few drivers will happily use step 5/6 for station stops.

 

[Kneedown]

I asked because my general impression is that with modern defensive driving techniques, the use of higher braking for normal running seems to be frowned on.

Certainly liberal use of Step 3 with a 3-step brake doesn't seem to be favoured, so I wondered if the same applied to the seven-step brake.

Are HST brakes are really variable then?

ALL brakes vary, even between units of the same class and indeed even the same unit on different days. That's why we perform a running brake test when joining a unit or changing ends. It comes down to a few things. Pressure in the brake cylinder can vary slightly within certain tolerances, age and level of wear of the brake block/pad, any contamination. So many things can affect braking performance.
On an HST, as has already been explained, the first application is to "Initial" for a few seconds. This has the effect of closing the ventilation flaps in the coaches to prevent fumes being drawn into the saloon. Then try and use steps 2 to 4 for normal braking, leaving the extra steps as back up should I feel the need. I was always taught to leave something in reserve. Good advice.

 

[Bikeman78]

If braking for stations start with step 1 as this prevents the brake burning smells entering the coaches. After about 5 seconds into step 2 or greater ...
If doing 125 and seeing an adverse signal will usually go straight to 3 or 4 to get the speed down. Although different HST sets have different standards of brake so depends much on the individual set...

The burning brake smell was routine for an HST 20 years ago. Now it only seems to happen when a driver comes across a double yellow in the middle of nowhere. Having said that I had a run on a pair of 317s last year where the driver was keen to make up time, which he did! Smelly brakes at every stop.

 

[Bletchleyite]

The burning brake smell was routine for an HST 20 years ago. Now it only seems to happen when a driver comes across a double yellow in the middle of nowhere. Having said that I had a run on a pair of 317s last year where the driver was keen to make up time, which he did! Smelly brakes at every stop.

Wasn't this issue caused by the air intake for the aircon being rather near the brakes, and solved (mostly) by moving it, or possibly now I think on putting flaps over it which closed when the brakes kicked in?

Edit: Ah, @Kneedown seems to confirm it is the latter.

 

[robbeech]

Wasn't this issue caused by the air intake for the aircon being rather near the brakes, and solved (mostly) by moving it, or possibly now I think on putting flaps over it which closed when the brakes kicked in?

Edit: Ah, @Kneedown seems to confirm it is the latter.

Do we know if the flaps were installed on all sets. Rarely notice on the LNER mk3 or 4 sets but frequently notice the smell on the EMT sets even for station stops.

 

[hexagon789]

On a class 390, usually step 2/3 (max 4) for a regular station stop.

When doing 125 and braking for a red, there are so many factors to consider. Obviously route knowledge will help determine how heavy the brakes need to be initially applied. There are 3 state banner repeaters as well at certain locations to help avoid heavy braking and give you extra braking distance as you can see if you have a double yellow from further away as some sections are extremely short. You also have to consider TPWS as some areas the TPWS is very ‘sensitive.’
Generally speaking, step 3/4 is a good brake application to make for double yellows. Step 2/3 if you are on a long straight and can see double yellows a few sections away.
It will also come down to the specific driver as Irish Rail said. Some drivers will use step 5/6 immediately when they see any adverse aspects while a few drivers will happily use step 5/6 for station stops.

Thank you, I thought using at the least, Step 6 would've been frowned on or is it more using it excessively?

The burning brake smell was routine for an HST 20 years ago. Now it only seems to happen when a driver comes across a double yellow in the middle of nowhere. Having said that I had a run on a pair of 317s last year where the driver was keen to make up time, which he did! Smelly brakes at every stop.

Never noticed it myself, but I've never had an HST at more than 100mph and I never got the impression the Chieftain was tightly booked Perth-Edinburgh either so likely no need for harder running.

Wasn't this issue caused by the air intake for the aircon being rather near the brakes, and solved (mostly) by moving it, or possibly now I think on putting flaps over it which closed when the brakes kicked in?

Edit: Ah, @Kneedown seems to confirm it is the latter.

And of course the pads used to contain asbestos...

Do we know if the flaps were installed on all sets. Rarely notice on the LNER mk3 or 4 sets but frequently notice the smell on the EMT sets even for station stops.

Think so, certainly material I've read suggests that all the HST trailers were fitted. LHCS Mk3s though I've no idea whether they got the flaps as well.

 

[hexagon789]

On a class 390, usually step 2/3 (max 4) for a regular station stop.

When doing 125 and braking for a red, there are so many factors to consider. Obviously route knowledge will help determine how heavy the brakes need to be initially applied. There are 3 state banner repeaters as well at certain locations to help avoid heavy braking and give you extra braking distance as you can see if you have a double yellow from further away as some sections are extremely short. You also have to consider TPWS as some areas the TPWS is very ‘sensitive.’
Generally speaking, step 3/4 is a good brake application to make for double yellows. Step 2/3 if you are on a long straight and can see double yellows a few sections away.
It will also come down to the specific driver as Irish Rail said. Some drivers will use step 5/6 immediately when they see any adverse aspects while a few drivers will happily use step 5/6 for station stops.

Thanks for the info.

I always get the impression that train handling questions are quite difficult in the UK context because compared to the Continent our railways I've been told very variable signal spacings!

 

[computerSaysNo]

Out of interest, what step of brakes are used while stopped at a station?

 

[PudseyBearHST]

Thank you,
I thought using at the least, Step 6 would've been frowned on or is it more using it excessively?

No problem.

If you really have to use step 6, then you have to.

If seeing double yellows and you put it in step 6 and wish to go past the single yellow at no more than 20mph, for example, there’s nothing wrong with that. You can argue that it’s not really required but no driver manager is going to tell you off for being too defensive.

It’s frowned upon when using it for drops
in (enhanced) permissible speed or for station stops. To give you an idea, if you hit the ramp of the platform at 35mph, generally speaking, step 2 with a touch of step 3 will bring you down to a good stop. If you have to use step 6, I imagine you’ll be hitting the platform well above 50mph.

With regards to short signal sections, this of course forms part of the route knowledge and you are more prepared on the approach to these sections. E.g. ensuring you have a green banner repeater at Wolverton.
As you have mentioned above about modern defensive driving techniques, these can be applied to areas that are known to have short signal sections, low adhesion areas or areas where there is a high chance of adverse aspects. For example, as you leave Kilsby tunnel on the down, speed goes back up to 125 EPS. There is a good chance that your third signal as you are coming around the bend may be a double yellow as you come on the long straight to Hilmorton and eventually Rugby. Signal sections are quite short such that you can see your red at the end of the long straight which takes you to Rugby station. So you may decide to not bother increasing speed from 110 back up to 125 after Kilsby until you know you’ve got the route set through Rugby. In fact quite a few services you can almost expect to have adverse aspects. E.g. XX00 of Euston to Manchester where a class 350 comes in front of you at Rugby and goes off at Attleborough. So by applying the above technique, you can avoid heavy braking.

 

[PudseyBearHST]

Out of interest, what step of brakes are used while stopped at a station?

Step 6 on a Class 390 and HIGH on a Class 221 (full service) and then Neutral.

 

[Kneedown]

Out of interest, what step of brakes are used while stopped at a station?

Step 2 on an HST, but if leaving the cab for any reason, eg to wash flies off windscreen, Full Service is used.

 

[driver_m]

I was always taught to make sure you have something in reserve, just in case you need it, and so far it has served me well and I’ve never really had to use step 6 other than when at a stand (as it is required). There are a couple of places where you might get a pair of surprise 2 yellows and need step 5 just to get the speed down quickly. (Wolverton & Norton Bridge used to be prime examples before the green banners were installed) but usually step 3 will do when I’m on a 390.

The one exception to this is if I get one yellow doing 125 on the Hixon line. (3 aspect signalling) Tons of room to bring it down to the red using a normal brake, but I have to err on the side of caution and trundle along to the red after drastically reducing the speed.

 

[hexagon789]

If you really have to use step 6, then you have to.

That is the answer is was looking for, confirmation that you use it if you have to.

If seeing double yellows and you put it in step 6 and wish to go past the single yellow at no more than 20mph, for example, there’s nothing wrong with that. You can argue that it’s not really required but no driver manager is going to tell you off for being too defensive.

Because, as I remember from an ancient BR training video - "safety before punctuality".

My only thought is that by going into 6 instead of say 4, you could provoke a slide you might otherwise not have provoked in poor adhesion conditions.

It’s frowned upon when using it for drops
in (enhanced) permissible speed or for station stops. To give you an idea, if you hit the ramp of the platform at 35mph, generally speaking, step 2 with a touch of step 3 will bring you down to a good stop. If you have to use step 6, I imagine you’ll be hitting the platform well above 50mph.

Hitting platform ramps at 50 seems to be the done thing on the continent. I recall utterly flying into Lausanne in Switzerland and coming to a stop bang on the mark and smooth as glass.

With regards to short signal sections, this of course forms part of the route knowledge and you are more prepared on the approach to these sections. E.g. ensuring you have a green banner repeater at Wolverton.
As you have mentioned above about modern defensive driving techniques, these can be applied to areas that are known to have short signal sections, low adhesion areas or areas where there is a high chance of adverse aspects. For example, as you leave Kilsby tunnel on the down, speed goes back up to 125 EPS. There is a good chance that your third signal as you are coming around the bend may be a double yellow as you come on the long straight to Hilmorton and eventually Rugby. Signal sections are quite short such that you can see your red at the end of the long straight which takes you to Rugby station. So you may decide to not bother increasing speed from 110 back up to 125 after Kilsby until you know you’ve got the route set through Rugby. In fact quite a few services you can almost expect to have adverse aspects. E.g. XX00 of Euston to Manchester where a class 350 comes in front of you at Rugby and goes off at Attleborough. So by applying the above technique, you can avoid heavy braking.

So as with so many things, route knowledge and experience are key to anticipate how you handle the train.

I was always taught to make sure you have something in reserve, just in case you need it, and so far it has served me well and I’ve never really had to use step 6 other than when at a stand (as it is required). There are a couple of places where you might get a pair of surprise 2 yellows and need step 5 just to get the speed down quickly. (Wolverton & Norton Bridge used to be prime examples before the green banners were installed) but usually step 3 will do when I’m on a 390.

The one exception to this is if I get one yellow doing 125 on the Hixon line. (3 aspect signalling) Tons of room to bring it down to the red using a normal brake, but I have to err on the side of caution and trundle along to the red after drastically reducing the speed.

So it's all about killing off most of the speed intially and then continuing on up to a potential red very cautiously - presumably to mitigate against potential SPADs from approaching too quickly?

 

[driver_m]

Yeah. It’s more a belt and braces approach for me. As far as I’m bothered, I haven’t been given a clear run and I’ll defensively drive up to it. It’s very rare to get a single yellow over there. Had it twice in all the years I e been driving, and it was only because I was following an EWS 92 which shows you how long ago it happened to me last! We’re told to be more cautious with unusual yellow aspects so as not to be caught out and it makes perfect sense.

 

[hexagon789]

Yeah. It’s more a belt and braces approach for me. As far as I’m bothered, I haven’t been given a clear run and I’ll defensively drive up to it. It’s very rare to get a single yellow over there. Had it twice in all the years I e been driving, and it was only because I was following an EWS 92 which shows you how long ago it happened to me last! We’re told to be more cautious with unusual yellow aspects so as not to be caught out and it makes perfect sense.

As a layperson as it were, I would agree that sounds eminently sensible and I can understand the thinking behind it.