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Post by superteacher on Jan 27, 2019 18:01:58 GMT
Anyway, back on topic.
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Post by sunnyday on Jan 27, 2019 20:11:30 GMT
345s actually do not have DOO cameras as they take images from platform mounted cameras instead. This choice was made because of the use of PEDs in the core which would render train mounted cameras almost useless. As such, I assume that the lack of images at certain stations means that those stations are not fitted with cameras. Apologises as I deal with Bombardier stock built in the last two decades I had thought the 345s were like everything else Bombardier has built for the mainline (and funny enough since the 345s) have DOO cameras. However the idea that PEDs mean you can't use DOO cameras seems a reason only for a few stations. I also believe then that the 345s are the first attempt to put the LU standard on the national network. It does however in light of recent incidents that a driver has no images of a platform seem to be at odds of how everyone else works. On the mainline the driver still retains responsibility for his train and is supposed to use cameras to check his train as he starts to take power. Most stock the cameras stays on until 3mph (historically units have a hard time telling the difference between 0 and 3mph). Are the staff on the platforms at Stratford LU/TfL Rail or GA staff? The platform staff on P5/P8 are TfL Rail. I guess the situation isn't any different at Stratford to how things are with the existing 315s, but it is interesting the leaky feed system wasn't installed at Stratford when it has been installed at other (currently) CD/RA platforms such as Gidea Park and Ilford on the up. |
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Post by phil on Jan 28, 2019 18:59:58 GMT
Correct, see here for examples: www.railsigns.uk/sect20page1/sect20page1.htmlMy understanding is that RA can only illuminate when the associated signal is showing a proceed aspect. I would assume for ATO-type signalling there is a similar interlock. No you can on signals I've dispatched from have RA on a red. It will only clear tho after a signal goes back. CD is not linked to the signalling however and is a simple light box.
Due to several incidents with drivers trying to pull away after having received the 'all clear' / right away from station staff or guards despite the signal showing a red aspect it has long been accepted that the RA must ONLY be illuminated when the signal to which it pertains is showing a proceed aspect. Anything else is to be treated as a wrong side failure and must be fully investigated.
While early installations may not have been interlocked in this way British Rail went round and modified all such indicators as a SPAD prevention measure back in the 1980s and such a feature was designed into all interlockings commissioned from then on as it was an obvious SPAD trap and in the pre TPWS days a pretty deadly one at that!
As you say, traditionally CD indicators have not been interlocked with the starting signal as it does not give permission for the driver to move and is only there for units operated Driver Only Operation - however the current signalling design standards say that a CD indicator must only illuminate when the signal is showing a proceed aspect.
Furthermore it is now also a requirement for new schemes that the CD or RA can only be shown if the track circuit / axle counter section in the platform is proved to be occupied. This change has been facilitated by the use of computer based signalling such as SSI, WestLoc, Smartloc which eliminates the need for extra wiring / relays as all the conditions / requirements are simply written into the software.
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Post by norbitonflyer on Jan 28, 2019 20:52:53 GMT
several incidents with drivers trying to pull away after having received the 'all clear' / right away from station staff or guards despite the signal showing a red aspect. Known colloquially as "ding-ding and away". Two fatal collisions, at Bellgrove and Paisley, both in the Glasgow suburbs, led to a tightening up of procedure. I have seen the same conditioned reflex on a crew-operated bus - a passenger rang the bell to get off at the next stop while the bus was standing at a red traffic light, and (although it was only one ding), the driver started away. |
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Tom
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Post by Tom on Jan 28, 2019 21:37:24 GMT
As you say, traditionally CD indicators have not been interlocked with the starting signal as it does not give permission for the driver to move and is only there for units operated Driver Only Operation - however the current signalling design standards say that a CD indicator must only illuminate when the signal is showing a proceed aspect.
Perfectly logical, as there is little point closing the doors with the signal at danger. |
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Chris M
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Post by Chris M on Jan 28, 2019 23:12:48 GMT
As you say, traditionally CD indicators have not been interlocked with the starting signal as it does not give permission for the driver to move and is only there for units operated Driver Only Operation - however the current signalling design standards say that a CD indicator must only illuminate when the signal is showing a proceed aspect.
Perfectly logical, as there is little point closing the doors with the signal at danger. That depends how tight your headway is. For maximum throughput you'd want the train to be in a position to depart as soon as the signal clears. |
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