Train rolling back at Farringdon

[jon0844]

This morning I was due for a meeting in Fleet Street, so took a FCC train from St Pancras to City Thameslink. It was a 319 (won't say what time for the sake of the driver) and as it crawled up to Farringdon and stopped, the doors opened to let people off and on.

About 5-10 seconds in, the train began to roll back. It moved pretty quick too, and must have moved about a metre or so before the driver stopped the train moving any further.

To me, that's quite serious even if the distance was quite small. As people were getting on/off, any faster/further and people would have fallen over for sure - and maybe the sudden need to jump sideways could have had someone fall down between the gap.

However, that didn't happen and after another 10 seconds or so, the doors closed and we carried on.

Now, a couple of questions;

a) It's on a steep hill, so it must be known concern. However, once the doors are open surely the brakes are firmly applied and what I witnessed couldn't happen unless there was some kind of fault?

b) The driver does the power switchover there, so perhaps didn't notice immediately the train was moving backwards. He reacted quite quickly.

c) If the train was to roll back as the driver had (for example) collapsed, what would stop it from rolling all the way back down the hill, the wrong way?

d) Why do these things keep happening to me?

 

[Crossover]

I'm not staff but it doesn't sound right. On point a it sounds like a potential wrong side failure as I was under the impression that brakes won't release until interlock has been gained

On point d, you must be cursed :P

EDIT: Oh and on point c, if the reverser is engaged the Vigilance Device would still be active I think. Otherwise I'm unsure as we have heard of trains rolling away before...

 

[Surreytraveller]

I do believe that on a 319, the doors being open prevent the train motoring, but the brakes can still be released.

 

[jon0844]

Being totally ignorant; is it easy to release the brakes my mistake? Are they locked in position?

Or indeed, like a lazy motorist (myself included) not applying a handbrake and just sitting on the brake pedal, could you hold them on instead of locking them on - then accidentally let go'?

 

[millemille]

Traction interlock only prevents the train being driven with the doors open, it doesn't prevent brake release and the train rolling...

Anti roll back systems have been worked on for years on underground stock to prevent the very scenario described.

I've investigated a few roll back incidents and invariably they are caused by the driver bringing the train to a stop using the hill start button to trim his speed and then forgetting to put the brakes into a service application with the BC/CPBC when stopped.

 

[jon0844]

If it happens, is the driver expected to report it or just cross his/her fingers and hope nobody noticed?

 

[barrykas]

Just a thought, but do 319s not have separate traction and brake controls?

 

[millemille]

c) If the train was to roll back as the driver had (for example) collapsed, what would stop it from rolling all the way back down the hill, the wrong way?

The Drivers Safety Device would apply the brakes. DSD - used to be called the "deadman's handle", basically a system that if a foot pedal or control lever is not kept pressed down or no controls are operated in the cab then every 15 seconds an alarm sounds which must be cancelled by the driver within 2-3 seconds, by pressing the pedal or lever, or an emergency brake application would occur. If you've ever been on a train that has come to a screaming halt for no apparent reason there's a good chance it's because the driver has "dropped the DSD".

 

[ChrisCooper]

All trains with power doors have a traction interlock which prevents power being applied when the doors are open. Brake interlocks tend to vary though. All modern units have them but I'm not sure about older units. At the vast majority of stations you could release the brakes and the train would go nowhere as it requires a reasonable slope to overcome rolling resistance and start moving. Accidentally releasing the brakes would be very difficult as for a start the brake handle is pushed away to apply, and it would also require a reasonable force to operate. Unlike car brakes the brakes are held as set without the need for the driver to do anything.

 

[millemille]

Just a thought, but do 319s not have separate traction and brake controls?

Yes they do.

Driver error could mean the brake control was moved the wrong way - particularly if the driver signs more modern stock with a CPBC and maybe got confused?

 

[jon0844]

The Drivers Safety Device would apply the brakes. DSD - used to be called the "deadman's handle", basically a system that if a foot pedal or control lever is not kept pressed down or no controls are operated in the cab then every 15 seconds an alarm sounds which must be cancelled by the driver within 2-3 seconds, by pressing the pedal or lever, or an emergency brake application would occur. If you've ever been on a train that has come to a screaming halt for no apparent reason there's a good chance it's because the driver has "dropped the DSD".

I am glad that works even if the train isn't powered, and going the wrong way, but 15 seconds could have allowed the train to move quite a long way down the hill! It would still be pretty disastrous given the doors were open at a platform!

 

[ChrisCooper]

Yes they do.

Driver error could mean the brake control was moved the wrong way - particularly if the driver signs more modern stock with a CPBC and maybe got confused?

They would still go the same way, away for apply, towards for release.

 

[JoeGJ1984]

Out of interest, what do drivers do with the brake when the doors are open? Do they leave it in full service brake? I asked because I have played with OpenBVE and I tend to put the brakes to B1 in order to get away quicker while waiting for the 'ready to start' signal from the guard. What is the proper way to do this? What do actual drivers do? What about vacuum brakes? (Because it takes time to fully release the brakes). Do the drivers start to release the pressure beforehand to make a quicker getaway?

I also seem to have the idea that if the controller is in forward or reverse with the doors open then there is an interlock which means the train can't move if the brakes are released. Can somebody confirm or refute this statement?

 

[millemille]

I am glad that works even if the train isn't powered, and going the wrong way, but 15 seconds could have allowed the train to move quite a long way down the hill! It would still be pretty disastrous given the doors were open at a platform!

The idea with DSD is that it requires a concious action - pressing a pedal down or keeping a control lever held down - to prevent the brakes from applying nigh on immediately. If the driver were to be incapacitated the brakes would apply immediately as the pedal or lever would be released, the alarm would sound but not be acknowledged.

If by some fluke the driver was incapacitated but still held the DSD down only then would the train start rolling and the alarm would sound after 15 seconds and as it would not be acknowledged then the brakes would apply.

 

[Skoodle]

378s automatically apply the brakes if the train rolls back and reaches 4mph.

 

[hairyhandedfool]

....Now, a couple of questions;

a) It's on a steep hill, so it must be known concern. However, once the doors are open surely the brakes are firmly applied and what I witnessed couldn't happen unless there was some kind of fault?....

The safety systems on a 319 allow the train to roll at a speed of 3-7mph before the brakes automatically apply.

....b) The driver does the power switchover there, so perhaps didn't notice immediately the train was moving backwards. He reacted quite quickly....

It is very easy to think the brakes are on when they are not, I know from experience, but the driver should know what position the brake handle is in.

....c) If the train was to roll back as the driver had (for example) collapsed, what would stop it from rolling all the way back down the hill, the wrong way?....

At that location a brake application would occur at a speed of 3-7mph (depending on the setting of the individual unit), however, the maximum time it would roll for would be one minute and four seconds from the time the last control was moved or activated.

....d) Why do these things keep happening to me?

Can't answer that, but I have seen trains roll for a fair distance with the doors open at Farringdon.

Out of interest, what do drivers do with the brake when the doors are open? Do they leave it in full service brake?....

Depend on the driver, location and his required actions at the stop. Most 'Thameslink drivers I know of will only apply the full brake (step 3) when at a stand in a station if leaving the cab. At Farringdon it was common for drivers to leave the cab briefly to inspect the position of the pantograph on Stones Faiverley fitted units (Brecknell Willis pans make a heck of a noise when lowered).

....I asked because I have played with OpenBVE and I tend to put the brakes to B1 in order to get away quicker while waiting for the 'ready to start' signal from the guard. What is the proper way to do this? What do actual drivers do? ....

'Thameslink' drivers are/were taught to have the brake in step 1, apply power to a maximum of notch 2, then release the brakes, and, when required, apply more power.

....I also seem to have the idea that if the controller is in forward or reverse with the doors open then there is an interlock which means the train can't move if the brakes are released. Can somebody confirm or refute this statement?

On a 319, the brakes will apply if one of the following has occured:

a) The train has reached a speed of 3-7mph with the doors open.
b) The DSD has not been reset.
c) An external door has been opened at a speed of more than 3-7mph.
d) A pass-comm has been activated.
e) A certain MCB has tripped.
f) A TPWS warning has not been acknowledged.
g) The master switch is in neutral.
h) The brake handle has been used in the driving cab.
i) The emergency brake has been applied in any cab.

Power cannot be taken on a 319 if the doors are open, the DRA is activated or the brakes are in step 2, 3 or emergency.

 

[pendolino]

Out of interest, what do drivers do with the brake when the doors are open? Do they leave it in full service brake? I asked because I have played with OpenBVE and I tend to put the brakes to B1 in order to get away quicker while waiting for the 'ready to start' signal from the guard. What is the proper way to do this? What do actual drivers do? What about vacuum brakes? (Because it takes time to fully release the brakes). Do the drivers start to release the pressure beforehand to make a quicker getaway?

I also seem to have the idea that if the controller is in forward or reverse with the doors open then there is an interlock which means the train can't move if the brakes are released. Can somebody confirm or refute this statement?

Personally, at a station with doors open: step 2, DDS to Neutral, unless at a red in which case Step 3 + Neutral + DRA.

With doors open and in running release, a lot of older stock will roll regardless of position of the DDS. Some newer stock applies the emergency brake if the door interlock is lost (e.g., the doors are open at a station).

 

[westcoaster]

a) It's on a steep hill, so it must be known concern. However, once the doors are open surely the brakes are firmly applied and what I witnessed couldn't happen unless there was some kind of fault?

b) The driver does the power switchover there, so perhaps didn't notice immediately the train was moving backwards. He reacted quite quickly.

c) If the train was to roll back as the driver had (for example) collapsed, what would stop it from rolling all the way back down the hill, the wrong way?

d) Why do these things keep happening to me?

a, first part yes, second part no.
b, sounds like what happened
c, nothing, until the unit gets to 9mph when the ssf /r will kick in
d, I don't know , but keep away from my train lol.

 

[185]

Happened at Leeds with a 155. My driver got off and went to the cafe on platform 12, the west end is downhill.

Assumed the door release would have put the brake on, he just left the brake handle in '0'.

I'm stood at the back and watching it roll until I dived on and got the back brake in.

Turns out, at the time, there was no modification or door interlock on 155s!! Jeez

 

[driver9000]

378s automatically apply the brakes if the train rolls back and reaches 4mph.

Every train I drive (BR DMUs) has this feature as do SSF fitted locomotives.

The Vigilance alarm doesn't sound as often as every 15 seconds, it sounds around every 60-90 seconds with no main controls (power/brake/AWS) touched. The alarm gives around 5 seconds before an emergency brake application is automatically initiated.

On the topic of brake handle position at stations. I leave the brake handle in step 1/Initial if running under greens, if faced with a red or having passed a yellow then I place the brake to Emergency and the direction switch to Neutral.

--- old post above --- --- new post below ---

I also seem to have the idea that if the controller is in forward or reverse with the doors open then there is an interlock which means the train can't move if the brakes are released. Can somebody confirm or refute this statement?

Releasing the doors on modern multiple units (including BR era) should cause the brake pressure to rise to full service and will not be released again until all doors are closed.

 

[Intermodal]

What about vacuum brakes? (Because it takes time to fully release the brakes). Do the drivers start to release the pressure beforehand to make a quicker getaway?

From what I've seen, the driver will fully destroy the vaccum if they are going to be there longer than a few moments, but shortly before departure time they will create 15 pounds of vaccum on the gauge, a nice balance between holding the train and enabling for a quick release.

 

[Redahead]

"Releasing the doors on modern multiple units (including BR era) should cause the brake pressure to rise to full service and will not be released again until all doors are closed."

Not on 455, 456 or 377s. No traction power can be taken, but no brake application occurs simply because a release has been put up. Can engage running release with the doors open...

 

[Smudger105e]

From what I've seen, the driver will fully destroy the vaccum if they are going to be there longer than a few moments, but shortly before departure time they will create 15 pounds of vaccum on the gauge, a nice balance between holding the train and enabling for a quick release.

Sorry to be pedantic, but vacuum is measured in inches (of mercury). 15" of vacuum sounds about right, 21" being release on a british vacuum braked train, and 0" obviously being full (emergency) application..

 

[Bald Rick]

Must have been the day for it yesterday; something similar happened at Stratford.

Hauled set stopped a bit short (DVT not in platform) conductor released doors, people start getting off, driver moves off to get DVT in, punters start wondering why they are on a cakewalk.