Unusual(?) Class 385 braking technique

[380101]

I believe they are 3-step rather than variable.

Class 385 has 0-100% variable braking, not 3-step although on the hmi screen it shows the equivalent 3 step positions on the brake/power section of the display

 

[thirdraildrive]

My general technique is to use brake step 1 at my known braking point, generally gets me on the platform edge at about 30mph, keeping it in 1 all the way down. Depending on the location of monitors I may release it and go back into it again once or twice or have to use some 2. I always try to release as I stop to give a smooth stop but you have the be very careful with it, badly timed and you can easily roll it back. When the Regen kicks out the brake force often seems reduced sometimes quite a lot so that's when a bit of 3 may be needed. If you have the space you can normally use 3 and throw it back to off and still achieve a smooth stop, but ultimatley the number one responsibility is safety and stopping on the monitors to have a safe dispatch is way more important than passenger comfort. Consider as well, all drivers have "those days" where they're timing for smooth stops will be a little off everyone has those days in all roles!

My TOC has units that coupled in multiple don't always like eachother, they fight each other, they are more and less powerful both braking and accelerating and when you are unlucky enough to have a really bad formation is can be a bit of a nightmare. You can do everything right and release just at the right time then get a massive whack from the rest of the formation, I like to think at least the pasengers towards the back would have felt a smooth stop but from the cab it feels a lot worse

 

[hexagon789]

Class 385 has 0-100% variable braking, not 3-step although on the hmi screen it shows the equivalent 3 step positions on the brake/power section of the display

Ah, I will freely admit its the hmi screen I've seen a photo of, I couldn't find a clear shot of the TBC that I could see the writing on.

Are 380s the same, because again I've only seen the "3-step" markings on the hmi?

 

[thirdraildrive]

Class 385 has 0-100% variable braking, not 3-step although on the hmi screen it shows the equivalent 3 step positions on the brake/power section of the display

That's a nice touch actually, such a good idea to assist drivers who have only ever driven with 3 brake steps to have an idea of where the equivilant would sit on the % scale, can use the same braking points and smoothly transition into driving them, love it!

 

[dctraindriver]

Many thanks for the reply.

Some of those "hard jolts" aren't actually the braking or even a 'hard brake' to stop. On our trains the rear unit will often bump into the front when coming to a stand. This is due to the uneven braking of each individual unit. Also, in DOO land, its often imperative to ensure an arcuate stop so that you are precisely on the stop mark and aligned to the DOO monitors. This also means that you may need a firmer brake to ensure a good stop.

In both those videos the unit looked pretty smooth under braking. I agree that constant brake/coast may be an issue but for more scientific purposes I'd like to know more. The Driver may be compensating for the track and prevailing driving conditions. Lots of things contribute to your braking technique.

One thing to also consider is the TOC driving policy. Most TOCs are moving away from aggressive driving and braking techniques. So what has happened (at my TOC) is that you tend to default to a lighter brake and "fan" the brake instead of smashing it into two and praying to Jebus you're gonna stop.

Overruns are complicated. Distraction would certainly be where you can rightfully say was 'unprofessional' but that then eliminates the braking technique. More often I would say that its the aggressive braking style that causes overruns. Drivers who love to hit a station hard, regardless of the conditions or that love a good late braking technique.

I'll also add the unit itself may be the cause. With 700s most of us hated the way it always kicked at the last second. Trying to get a smooth stop is a matter of professional pride. 700s were/are a nightmare to stop smooth. Just as you stop the tread brake will kick in an the unit will come top an abrupt halt. Some units have various braking foibles that can affect how you brake. Other units I drive have a 'blended brake' and will switch from regen brake to friction at a set speed. More often than not the blending is off and the friction kicks in and causes a jolt. One of our units is infamous for just dropping out entirely and the unit will lurch forward. To combat the lurch you add more brake to compensate. Or you are in step two when the unit drops the regen and you get a sudden brake two application.

All in all, braking a train is more complicated than we think.

Hope that helps.

I find the brake on a 707 really good and smooth to stop. Surprised there’s such a difference.

 

[ComUtoR]

I find the brake on a 707 really good and smooth to stop. Surprised there’s such a difference.

707s and 700s are very similar. I'd agree that the 707 brake is smoother. It all depends on where the blending point is. 700s were pretty awful when they first entered service and they had to adjust the passenger jerk as it was pretty heavy on the anchors. I think this came up in a thread a while back. 707s have had some software updates compared to 700s so that might explain a smoother stop.

 

[380101]

Ah, I will freely admit its the hmi screen I've seen a photo of, I couldn't find a clear shot of the TBC that I could see the writing on.

Are 380s the same, because again I've only seen the "3-step" markings on the hmi?

Yeah, 380s are the same.