Doors partially opened on moving Northern Line train!

[brettb]

Hi all,

I'm a long time lurker but an extraordinary event has made me start posting here...

Anyway, I commute from East Croydon to Moorgate via Southern to London Bridge then on the Northern Line every day. This morning during the peak I got a North bound Northern Line tube train from London Bridge. I was the last passenger to get on into the last carriage and stood just inside the door.

As the train moved away it lurched a bit and I grabbed hold of the rubber seal between the two closed doors. To my amazement the doors gave way and I and I was able to push them open 1 or 2 inches. I felt as if they would have opened all the way. Thankfully I pushed them closed again (and I think the guy standing next to me might have assisted - it happened very quickly indeed).

I have reported it to TFL and gave them the carriage no. but just wondered how serious this was and how often it happens?

They told me the train should automatically apply the brakes if it senses a door is open but that didn't happen. The driver was probably in the tunnel by the time it happened so they probably wouldn't have noticed it.

I might call TFL again next week but is it worth escalating it? Shouldn't there be some sort of interlocking system, or does it only work above a certain speed?

I do remember doors flying opening a couple of times when I was a school kid travelling along the Sussex Coast on the old slam-door trains. I thought things were better these days :roll:!

 

[Domh245]

London Underground doors tend to have a pushback mechanism that allows them to be moved a couple of inches without breaking any interlocks (which do exist!) to remove trapped clothing/umbrellas/limbs etc. I can't go into detail, although I'm sure someone can.

 

[rebmcr]

People bracing against the doors in the 'wrong' direction when tube trains are accellerating happens nearly every day on my Jubilee commute — and it causes a suddent jolt as the traction power is cut. This causes the passenger's force on the door to stop, it closes again, and the train continues (with them more than likely being a lot more careful).

About half the time the driver will make an announcement about leaning on the doors, but IMO that is poor phrasing that implies an outward force rather than a backwards force. I didn't realise that the above was the cause of the cutouts (previously I assumed worn patches of conductor rail in the repeated-station-accelleration positions) until I did it myself during deceleration coming into a station — of course this doesn't give the telltale jolt as cutting traction power during braking doesn't have any noticable effect.

 

[bramling]

Hi all,

I'm a long time lurker but an extraordinary event has made me start posting here...

Anyway, I commute from East Croydon to Moorgate via Southern to London Bridge then on the Northern Line every day. This morning during the peak I got a North bound Northern Line tube train from London Bridge. I was the last passenger to get on into the last carriage and stood just inside the door.

As the train moved away it lurched a bit and I grabbed hold of the rubber seal between the two closed doors. To my amazement the doors gave way and I and I was able to push them open 1 or 2 inches. I felt as if they would have opened all the way. Thankfully I pushed them closed again (and I think the guy standing next to me might have assisted - it happened very quickly indeed).

I have reported it to TFL and gave them the carriage no. but just wondered how serious this was and how often it happens?

They told me the train should automatically apply the brakes if it senses a door is open but that didn't happen. The driver was probably in the tunnel by the time it happened so they probably wouldn't have noticed it.

I might call TFL again next week but is it worth escalating it? Shouldn't there be some sort of interlocking system, or does it only work above a certain speed?

I do remember doors flying opening a couple of times when I was a school kid travelling along the Sussex Coast on the old slam-door trains. I thought things were better these days :roll:!

The doors are designed this way, they are designed to be able to be pushed open by a couple of inches to allow any trapped items to be removed. If you look carefully you'll notice one of the rubber seals is thicker than its counterpart, this indicates which door can be "pushed back". They are pushed against a strong spring and beyond a certain point reach a stop so cannot be pushed back any further. Obviously some springs are stronger than others, however it's quite common for jolts or someone leaning on the door to see the doors open slightly. Quite normal, and in accordance with the train's design.

Regarding the brakes not coming on, the trains are designed so that loss of interlock will cause motoring to be inhibited, but will not apply the brakes. However the driver may choose to apply the brakes - especially departing a platform or if the interlock is lost for more than a moment.

The latest trains (Victoria Line and S stock) have a different design and the doors are fully locked closed, instead thay have a sensitive edge detection system to deal with potential trapped objects.

 

[whoosh]

Paragraphs 43-69 of this accident report may help you understand how the doors on tube trains pull back to allow clothing to be extracted:

https://assets.publishing.service.gov.uk/media/56de93eae5274a036b00000d/R042016_160309_Clapham_South.pdf

 

[Daniel]

I think others have explained what happened quite well, it sounds exactly like an instance of pushback on the doors.

All I will add it, well done for reporting it with the carriage number - it means something can actually be done (the train has been checked) - but as you do say you did think the door would open all the way, if anyone ever does see a fault on a train that has the potential to cause harm, it's always best to report it at the next station as opposed to via customer services. Obviously if someone is actually *in* danger, for example if the door was actually fully open whilst the train is moving, pull a passenger alarm.

 

[Nym]

Ooops, already been said.

Doors have pushback, as above.