Central Locking System on HST's

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ryan125hst

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I was under the impression that on HST's (and all other modern trains for that matter), the train's breaks would only release when all the doors are shut and locked.

However, I have seen two videos on You Tube today that prove this to be incorrect. Both are Grand Central HST's and both clearly show the Central Door Locking lights to be illuminated.

The first shows a GC HST moving slowly through a depot with all of the CDL lights illuminated.

http://www.youtube.com/watch?v=KHXTuz66N5o&feature=related

The second is a very short GC HST being hauled by a class 47 at Darlington. The CDL lights on one of the coaches are clearly on, indicating the doors are unlocked. This is even more strange as it was obviously moving at high speed on the ECML rather than just a slow depot movement.

http://www.youtube.com/watch?v=lUyo1Vs332M at about 1:57 into the video.

Is it possible to disable the CDL on HST's (I'm guessing it's only allowed when no passengers on onboard or in an emergency)? Is this just a Grand Central thing, or do all HST's, or even all passenger trains, have this?

Can it be done on a coach by coach basis as well as the whole train?

What was the purpose of having the doors unlocked, especially on the train that was on the ECML?

Thanks
 
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Temple Meads

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As far as I'm aware the brakes can be released at any time by the driver (they are a separate system), and certainly I've never heard of the CDL and the brakes being linked, however a driver would probably not usually release the brakes until the guard has given his buzzer.

I expect the option to remotely operate the doors is in the box thing the guards use in the vestibules to operate the CDL, there is a lot of buttons in there.

But please bear in mind that I'm not 100% sure about any of this.
 

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ainsworth74

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My understanding is that on HSTs the CDL is not interlocked with the break systems, so it's perfectly possible for the driver to release the breaks whilst the doors are unlocked and even open (one danger with HSTs is that it's possible for a door to be only partially closed and on 'the latch' and therefore not fully locked but to a casual glance seem closed).
 

ryan125hst

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My understanding is that on HSTs the CDL is not interlocked with the break systems, so it's perfectly possible for the driver to release the breaks whilst the doors are unlocked and even open (one danger with HSTs is that it's possible for a door to be only partially closed and on 'the latch' and therefore not fully locked but to a casual glance seem closed).
That would make sense as the CDL was added later, not from new. Saying that, the photo uploaded by Temple Meads shows the words "CDL air pipe connections". This suggests that they are linked, unless air is used for something else for the CDL.
 

driver9000

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The CDL is not tied into the brake pipe and it is possible to move the train with the CDL released although I'm not sure about the air connections diagram. I don't recall ever seeing the diagram on loco hauled mk3 coaches or even mk2 coaches although they were fitted with CDL.

Modern MUs do not have a brake pipe, instead using an electrical wire which must be energised to prove the brake continuity. Several items of equipment on the train such as doors are wired into the brake continuity wire which will break the circuit and bring on an emergency brake application.
 

Aictos

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My understanding is that on HSTs the CDL is not interlocked with the break systems, so it's perfectly possible for the driver to release the breaks whilst the doors are unlocked and even open (one danger with HSTs is that it's possible for a door to be only partially closed and on 'the latch' and therefore not fully locked but to a casual glance seem closed).
On the East Coast HSTs, the Central Door Locking is certainly not interlocked with the Braking Systems as a result, a door can be left on the catch and the train will move anything up to line speed.

This obviously isn't safe, but until a much improved CDL is available then this will always be the case.
 

driver9000

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On the East Coast HSTs, the Central Door Locking is certainly not interlocked with the Braking Systems as a result, a door can be left on the catch and the train will move anything up to line speed.
I may be wrong but I always thought that with a door on the catch the bolt wouldn't drop and the light would stay on to alert dispatcher/crew to the door not being fully shut.
 

ainsworth74

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I may be wrong but I always thought that with a door on the catch the bolt wouldn't drop and the light would stay on to alert dispatcher/crew to the door not being fully shut.
I'm fairly sure flamingo (who works for FGW on their HSTs) has said that the bolt will happily drop even if the door is on the catch meaning that the lights go out and it looks fine from that perspective.
 

driver9000

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I'm fairly sure flamingo (who works for FGW on their HSTs) has said that the bolt will happily drop even if the door is on the catch meaning that the lights go out and it looks fine from that perspective.
Fair enough, it has been a while since I've been on a slam door train :)
 

transportphoto

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As far as I am aware, the door locking on Mk3s are simply dead locks that drop down, hence the 'clunk', as soon as the door lock button is pressed, the guard does not operate a local door, (s)he simply keeps it open. The dispatcher / guard then checks all doors again, all those fully closed door handles will appear as shown here (click for larger, sourced from Wiki Commons)


With the handle appearing as a ' *-- ' .

Whilst on the latch the handle is at a 45 degree downward angle and the door would be protruding from the body.

_____

The hazard lights extinguish once that dead lock drops, the doors can be wide open when this happens. All of the doors closed at that time / are closed after that are locked. It is not linked to the braking system like it is on modern MU's

TP
 

brillopad

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The hazard lights extinguish once that dead lock drops, the doors can be wide open when this happens. All of the doors closed at that time / are closed after that are locked. It is not linked to the braking system like it is on modern MU's

TP
This is a reason for slow running HSTs in Cornwall - there can be at least five unmanned stations where the TMs have to walk the entire length of the train checking doors.
 

dk1

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As has been said many times on here, CDL was a very cheap & cheerful option to stop silly people falling out of trains. Traction interlock was dissmissed as to expensive at the time. Many 15X units also where not fitted in their early days.
 

Old Timer

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CDL was introduced in the early 90s after we had suffered a spate of people falling out of doors. I believe that in all cases no fault could be found with the doors. In one instance a Guard had fallen from the train on the GW and it could only be surmised that he had spotted the door ajar and tried to close it whilst the train was moving.

Matters were then further complicated by an incident where a passenger fell out of a door on an Up express at Coton Crossing. A Dow train was sent in to examine the line but was unable to stop before running over the body which was straddling one of the rails.

It subsequently became a big iissue over whether Drivers could examine the line at night without a proper high intensity frontal light, and a prohibition was then placed i cases where the where the traction unit was not so equipped and was single manned. As an interim measure examination had to be accompanied in such circumstances. This led itself to the adjustment to the frontal lights, but the spate also caused HMRI to require that a form of door locking was imposed, hence CDL.

I am pretty convinced that as fitted, the lights only extinguished after the doors were proven locked. First catch should have resulted in a failure of the CDL lights to go out. as first catch is not a secure lock, it is only there to hold the door against swinging out under braking.
 

83G/84D

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CDL lights illuminated on an HST does not stop the brakes being released and train moving. HST's can and do depart from stations with a door "on the catch". In that situation the train would be stopped,door secured and locked out of use until a full check can be made of it on a depot.
 

shedman

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We move HSTs around Neville Hill with doors unlocked to prevent us having to unlock the doors everytime we stop. The video of the GC HST with its doors unlocked, all doors should be locked before it leaves the depot on an ECS move but also the budget lock (midway up the door level with drop light) should also be locked, this prevents anyone trying to enter the train if it was to stop for a signal in a platform, leaving the door on catch.
 

Aictos

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I may be wrong but I always thought that with a door on the catch the bolt wouldn't drop and the light would stay on to alert dispatcher/crew to the door not being fully shut.
Not the case sadly, :(

I'm fairly sure flamingo (who works for FGW on their HSTs) has said that the bolt will happily drop even if the door is on the catch meaning that the lights go out and it looks fine from that perspective.
As someone who deals with them from a dispatching prospective day in day out, any door on a HST (except the sliding door in the power car) can be left on the catch which like ainsworth74 has correctly said above means the bolt will drop and the hazard light will go out even though the door is not safely secured.

Any train which is discovered to have a door on the catch is usually stopped by the signaller at the next possible location normally the next station and the offending door made secure.
 

jamieP

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The CDL is not tied into the brake pipe and it is possible to move the train with the CDL released although I'm not sure about the air connections diagram. I don't recall ever seeing the diagram on loco hauled mk3 coaches or even mk2 coaches although they were fitted with CDL.

Modern MUs do not have a brake pipe, instead using an electrical wire which must be energised to prove the brake continuity. Several items of equipment on the train such as doors are wired into the brake continuity wire which will break the circuit and bring on an emergency brake application.
On older EMUs you are able to reliese the brakes with the doors open but not able to get power but if the unit is moving at more than 5mph and someone forced a door open the the emergency brakes would come on.

JP
 

driver9000

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On older EMUs you are able to reliese the brakes with the doors open but not able to get power but if the unit is moving at more than 5mph and someone forced a door open the the emergency brakes would come on.

JP
You can on some DMUs too.
 

VP185

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From my experience I think the CDL does require an air supply to operate as well as an electrical feed.
I've certainly attached locomotives to 'dead' sets and as soon as an air supply is provided all the CDL hazard lights would be illuminated.
I'm also fairly certain in the event of a total loss of power to the coach that once the batteries have been drained the CDL would release. Presumably, this is necessary in the event of an emergency to enable the doors to be opened.

Don't know if the operation of the passcom equipment will illuminate a hazard light to alert staff to that coach though? That's the only reason I could see one being illuminated on the mainline.

I know the system can be isolated on individual coaches by removing the air and electrical fed. In that scenario, the hazard light would also be extinguished.
 

BestWestern

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An incident reportedly occurred last year in which an HST (TOC and location to remain anonymous) arrived into a station but pulled up short, missing the stop mark by a small distance. The Driver attempted rectify his stopping position and powered up, but unfortunately the Guard had already released the CDL, and the train moved in the platform with doors unlocked and open. Thankfully, nobody got hurt, but it goes to show that there is very definitely no door/brake interlock on HST's, and the consequences of it can be quite startling. Thankfully that type of incident is of course very rare, but 'door on catch' is not unusual.
 

louis97

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Its also worth noteing that if the Train Manager is operating the CDL from a passenger door, the bolt will not lower until the TM takes his key out of the CDL panel at that door. This is so the TM does not have to release all doors again, should he need to stop the train and/or return to the platform after locking and closing his door.
 

HSTEd

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I remember a rake of Mark 4s moving with the doors open years ago at Grantham....
It was dark and platform staff gave the flag and whistle before the guard had closed the doors, indeed before passengers had finished embarking.
My mother was with me at the time and our bag ended up on the train and us on teh platform.

Another odd thing about thing about that day was that it was a northbound train in Platform 4 which does not happen very often any more.
 
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