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#52
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#53
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![]() "Steve Fitzgerald" ] wrote in message ... In message , writes There are of course station starters (as far as I know at every station but I'm sure someone will come along and tell me otherwise) Croxley... -- Cheers, Steve. Change jealous to sad to reply. |
#54
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On Sep 10, 1:10*pm, "Richard J." wrote:
Recliner wrote on 10 September 2010 12:50:33 ... "Alan Ben *wrote in message On Sep 10, 11:38 am, *wrote: *wrote in message On Fri, 10 Sep 2010 08:53:12 +0100 Roland *wrote: In message5ZudnY273pDFGRTRnZ2dnUVZ7qSdn...@giganews. com, at 20:05:28 on Thu, 9 Sep 2010, remarked: You would have thought the signal allowing trains out of the bay platform would be interlocked to the points being set correctly for the route over the crossover, wouldn't you? Even in the presence of a fault condition (which they've apparently admitted)? So much for signals being failsafe. Failsafe unless the failsafe fails. Which it obviously did. Surely it was still failsafe? No trains were signalled to collide with each other. Yes they were. One train was on the line working in the wrong direction. Would you drive the wrong way on a motorway? But would the signals have stayed green if the trains approached each other closely enough to collide? But after passing the wrongly-set points, the train departing from Plaistow was travelling west on the eastbound track, and would not have any signals to see. I'm not sure if it would have been back-tripped, but the train that ran backwards downhill on the Northern some years ago because the driver was asleep wasn't tripped for several stations IIRC. -- Richard J. (to email me, swap 'uk' and 'yon' in address) Which is exactly why trains now have run back protection, which applies the emergency brakes if the train runs more than six feet in the reverse direction. |
#55
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In article , ] (Steve
Fitzgerald) wrote: In message , writes What seems to be rare on LU is three aspect signals. There used to be one at the entrance to the Southbound platform at East Putney but that might be BR practice. On LU They are generally speed controlled signals and work in a subtly different way although they are still stop signals and have a train stop. If they show green, there is a clear route set and no speed checking is in place. If they show red, speed checking is in place and the signal will show a yellow aspect and the train stop will drop when the train's speed has been proved below a set figure. They are mainly used to protect reduced overlaps on signals to ensure a train doesn't go thundering through an area with the potential risk of collision. LU rules could have applied at East Putney then, with the speed control for the approach to the junction at the platform ends. All speed control signals seem to work in slightly different ways depending on the local requirements and road learning includes these nuances. Of course where we share with BR then their signalling practices are in force. The example at East Putney was on non-shared track but I think has been removed. It may have dated from the days when some trains non-stopped East Putney. -- Colin Rosenstiel |
#56
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![]() That's got Bob Crow written all over it. On the roads, speeding drivers get sent on a Speed Awareness Course, but on the tube, it's the trains themselves that get sent on the collision course. |
#57
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In message
, upinthesky writes But after passing the wrongly-set points, the train departing from Plaistow was travelling west on the eastbound track, and would not have any signals to see. I'm not sure if it would have been back-tripped, but the train that ran backwards downhill on the Northern some years ago because the driver was asleep wasn't tripped for several stations IIRC. Which is exactly why trains now have run back protection, which applies the emergency brakes if the train runs more than six feet in the reverse direction. Except that the train in question would have been going in a forward direction so everything you allude to is void. -- Steve Fitzgerald has now left the building. You will find him in London's Docklands, E16, UK (please use the reply to address for email) |
#58
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On 12 Sep, 23:46, Basil Jet wrote:
That's got Bob Crow written all over it. On the roads, speeding drivers get sent on a Speed Awareness Course, but on the tube, it's the trains themselves that get sent on the collision course. I think I follow your play on words, but I don't follow the mention of Bob Crow. Is it just one of those things that's randomly inserted after a certain number of words? |
#59
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[Yes, I only just saw this thread.]
In message , Steve Fitzgerald ] wrote: What seems to be rare on LU is three aspect signals. There used to be one at the entrance to the Southbound platform at East Putney but that might be BR practice. On LU They are generally speed controlled signals and work in a subtly different way although they are still stop signals and have a train stop. If they show green, there is a clear route set and no speed checking is in place. If they show red, speed checking is in place and the signal will show a yellow aspect and the train stop will drop when the train's speed has been proved below a set figure. I'm not sure if any still do, but they used to show red+yellow (with train stop up) to show the train had entered the timing track circuit, then change to plain yellow (with train stop down) after sufficient time to ensure the train had slowed enough (if it hadn't, it would be tripped before the signal could change). Of course where we share with BR then their signalling practices are in force. Only when it's their track. There *are* true LU three- and four-aspect signals on the Metropolitan Line north of Harrow-on-the-Hill. -- Clive D.W. Feather | Home: Mobile: +44 7973 377646 | Web: http://www.davros.org Please reply to the Reply-To address, which is: |
#60
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In message , Steve Fitzgerald
] wrote: Does 'stop signal' mean 'signal capable of telling a train to stop', ie anything that can go red, as opposed to route indicators etc? Basically yes. Of course a route indicator will always have a stop signal with it Not so. On LU, if a signal with a route indicator has a repeater in rear, the repeater has a route indicator as well. This even applies to fog repeaters. Even on the "big railway", there's the Preliminary Junction Indicator, which doesn't have to be associated with *any* signal, let alone one capable of showing red (that is, it can stand alone or be placed above a distant signal). -- Clive D.W. Feather | Home: Mobile: +44 7973 377646 | Web: http://www.davros.org Please reply to the Reply-To address, which is: |
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