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Post by superteacher on Jul 27, 2010 22:51:00 GMT
Haven't seen this mentioned on this site, but found this on another site:
"The sensitive edge made an 09 stock train stop on its way out of a station. But with its rear end still in the platform, the train heind - 67 stock - came into the platform. It stopped in time to avoid a collision, but the dangers are obvious."
Can't find any official reports of it either. Anyone know anything about it?
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Tom
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Post by Tom on Jul 28, 2010 0:03:50 GMT
I haven't heard anything, but I do know that the signalling system is designed to allow trains to get very close together leaving platforms, such that if the first train is stopped on departure an apporoaching second train is running in almost on the border of tripping, which sounds like the case here.
In any case the overlap is sufficient that a collision will not occur, but it isn't a pleasant feeling for the driver seeing the tail lights of the train in front!
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North End
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Post by North End on Jul 28, 2010 9:47:35 GMT
Haven't seen this mentioned on this site, but found this on another site: "The sensitive edge made an 09 stock train stop on its way out of a station. But with its rear end still in the platform, the train heind - 67 stock - came into the platform. It stopped in time to avoid a collision, but the dangers are obvious."Can't find any official reports of it either. Anyone know anything about it? Someone's talking rubbish. The signalling on the Victoria Line is designed to do this. It's perfectly normal. At all stations from Seven Sisters to Stockwell inclusive, when a train starts to leave the platform, the home signal will turn from red to lunar white. An ATO-driven train will then start to creep into the platform at 22 mph. Because the departing train will be accelarating normally to line speed, the arriving train should never catch up. However if the departing train stops unexpectedly (e.g. a passenger alarm) then the arriving train will experience a loss of codes and will stop within the calculated safety overlap. This is similar to the multi-home signalling used on all LUL lines, the only difference being there are no signals or markers provided - it's all done by the ATO system. If this story has originated from a concerned Train Operator, this highlights poor training, as this feature of the original Vic Line ATO system should be well known to Victoria Line staff, especially Train Operators. |
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Deleted
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Post by Deleted on Jul 28, 2010 11:50:50 GMT
Is this similar to the Central line ATO where at some stations there are block markers mid-way along the platform?
This allows an approaching train to closely follow a departing train into the station, but safely stop should the departing train come to grief?
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Post by superteacher on Jul 28, 2010 12:22:45 GMT
Haven't seen this mentioned on this site, but found this on another site: "The sensitive edge made an 09 stock train stop on its way out of a station. But with its rear end still in the platform, the train heind - 67 stock - came into the platform. It stopped in time to avoid a collision, but the dangers are obvious."Can't find any official reports of it either. Anyone know anything about it? Someone's talking rubbish. The signalling on the Victoria Line is designed to do this. It's perfectly normal. At all stations from Seven Sisters to Stockwell inclusive, when a train starts to leave the platform, the home signal will turn from red to lunar white. An ATO-driven train will then start to creep into the platform at 22 mph. Because the departing train will be accelarating normally to line speed, the arriving train should never catch up. However if the departing train stops unexpectedly (e.g. a passenger alarm) then the arriving train will experience a loss of codes and will stop within the calculated safety overlap. This is similar to the multi-home signalling used on all LUL lines, the only difference being there are no signals or markers provided - it's all done by the ATO system. If this story has originated from a concerned Train Operator, this highlights poor training, as this feature of the original Vic Line ATO system should be well known to Victoria Line staff, especially Train Operators. Shall we say that my quote originated from a somewhat left wing, militant site . . . |
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Deleted
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Post by Deleted on Jul 28, 2010 14:45:15 GMT
In any case the overlap is sufficient that a collision will not occur, but it isn't a pleasant feeling for the driver seeing the tail lights of the train in front! Even on manually driven lines, there are areas where it's not unusual to see the tail lights of the train in front, drivers should be familiar with the areas where this can happen. |
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Chris M
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Post by Chris M on Jul 28, 2010 14:59:59 GMT
My initial thought was that this wasn't written by a t/op but by a (presumably relatively inexperienced) station assistant. tfc, Tom and Northend's postings suggesting that a driver should be familiar with this happening combined with other recent posts about the amount of training SA's get these days do nothing to dissuade me from this thought. An experienced t/op wouldn't think sufficient of it (or necessarily know why the 09 stock stopped - could have been a pax pulling the alarm) to make a report about it.
Given the stated source though, it would not surprise me to learn the sensationalism was added by someone who did not witness the incident but who doesn't like the new train for whatever reason.
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Post by superteacher on Jul 28, 2010 15:33:18 GMT
Of course, the worrying thing about all this is that this information was obtaned from a Google search - I happened to come across it, but I have sufficient knowledge of the underground to question it - I thought it sounded fishy from the outset. However, if the Evening Standard gwt hold of such information, you can imagine the headlnes.
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Tom
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Post by Tom on Jul 28, 2010 20:02:09 GMT
Is this similar to the Central line ATO where at some stations there are block markers mid-way along the platform? Similar, but in this case there are no markers. The Central Line code circuits are designed that no train should ever be brought to rest half way into a platform. Either you get a clear, but progressively slower run in or you don't enter the platform at all. However there are of course one or two exceptions to prove the rule! |
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Tom
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Post by Tom on Jul 28, 2010 20:05:05 GMT
Shall we say that my quote originated from a somewhat left wing, militant site . . . Oh... *that* site. I used to subscribe to it for a while but gave up when it was quite clear they were spouting off and scaremongering on subjects they knew absolutely nothing about... |
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Deleted
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Post by Deleted on Jul 28, 2010 20:48:30 GMT
Iv'e come across that site before, workers liberty I believe it's called, I have read a few articles on there and it's all just full of doom and gloom!
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Deleted
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Post by Deleted on Sept 28, 2010 19:30:16 GMT
If you take a closer look at a Victoria Line platform's track, you will see a set of insulated block joints at one-third platform length, and another set at two-thirds platform length. This enables the rearmost third of the track to be fed with 180 code for the approaching train (180 code is coasting/braking pemitted only), the centre third track section to be left de-energised in order to cause any train cab over it to slam on the emergency brakes, while the third section is occupied by the rear half of the departing train, so its also de-energised. Only the section in front of the departing train (i.e. in the tunnel) has 420 code required to Start up a train from Station.
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mrfs42
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Post by mrfs42 on Sept 28, 2010 19:58:19 GMT
If you take a closer look at a Victoria Line platform's track, you will see a set of insulated block joints at one-third platform length, Third of the way in... ISTR that's the 82 second block joint with a co-terminous 22/25mph overlap. |
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