mrfs42
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Post by mrfs42 on Oct 2, 2007 10:20:10 GMT
Well, not just about these two signals - more to do with additional bits of equipment next to the signals.
One seems to be a camera - presumably this is a feed to the Regulators to check on the destination shewn by the approaching unit?
What are the other two bits - one looks to be a light that illuminates as the train approaches - presumably this shines on the destination blind for the regulators. The other thing looks to be about the same size as an 'A' light stencil - I've seen these on other signals one at Wembley Park that seemed to be able of shewing 'M' but was mounted near the main stick rather than the disc.
In the example of the title, the light that illuminated was above the 'D off' sign, with the camera to the approaching motorman's right and the thing about the same size as an 'A' light above that.
Any thoughts?
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Deleted
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Post by Deleted on Oct 2, 2007 12:37:38 GMT
I believe one of the two bits is a camera that shows a video feed of the train's number, not the train's destination blind. Harsig has posted in the past about such cameras and how they prevent a great deal of stress on his part when manning the SCC at Baker Street. In fact, both bits may be cameras - I believe the DMT at Earl's Court now has a video feed of all four platforms, to assist him in train reformations. Channeling COLIN: www.trainweb.org/districtdave/assets/images/EC6a.JPG |
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Deleted
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Post by Deleted on Oct 2, 2007 13:07:36 GMT
The light that illuminates as the train approaches sounds like the "tripcock tester" visual.
All four platforms at Earl's Court have one.
The light illuminates when the approaching train enters the test track section. The tripcock arm runs over a sloped greased ramp and through a width gauge
There are then 4 possible outcomes.
Light goes out (so ramp was depressed, trip arm present) and train is not tripped (trip arm not out of gauge) - test passed.
Light goes out (ramp depressed and trip arm present), but train is tripped (trip arm probably hanging too low) - test passed, but train maintainer needed to tend to trip arm.
light remains on (ramp not depressed, trip arm missing or out of gauge) train NOT tripped (trip arm missing or very out of gauge). Test failed. Train out of service and second staff member needed, train must not be operated in excess of 15mph.
Light remains on (ramp not depressed, trip arm missing or out of gauge) train IS tripped (trip arm present, but out of gauge, train tripped on the width gauge). Test Failed - train out of service and second staff member required. train must not be operated in excess of 15mph
In essence if the light stays on the test has been failed, i believe this also sets off an alarm in the control room.
If a second train then fails the test, it is deemed the test equipment is faulty and that train remains in service. If a third train passes the test after the preceding two failed, it is then presumed the first two trains both genuinely failed and the second train is now withdrawn from service.
I'm not sure what the "A" or "M" light being described is though !
Some locations do have an infra red light that shines onto the train set number, but isn't visible to the human eye.
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Colin
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Post by Colin on Oct 2, 2007 13:29:14 GMT
Image quoted above:  The blue looking light, to the right of the repeater plate is the trip cock tester. The square box above it is a camera and shows the whole front of the train - this is/can be viewed by the line controller, DMT's and station station staff. The reason the whole front of the train is in view is threefold - service control are interested in number & destination, DMT's are interested in number & whether or not a driver is present and station staff are interested in destination. The round thing above the camera is, I'm led to believe, a tool that's supposed to automatically read the the train numbers - I'm further led to believe that it hasn't worked for years, if ever. |
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Tom
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Post by Tom on Oct 2, 2007 14:17:43 GMT
They worked (in a fashion) about eight years or so ago.
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Deleted
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Post by Deleted on Oct 2, 2007 15:30:24 GMT
it did work thats why the actual train numbers went from white to yellow so the camera could pick them up but again it had trouble picking certian numbers up and the one at monument e/b would never pick up a circle number just used to give ? ? ? as the number but it was decommisioned about 7 years ago as tom states
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Post by tubeprune on Oct 2, 2007 18:33:24 GMT
it did work thats why the actual train numbers went from white to yellow so the camera could pick them up but again it had trouble picking certian numbers up and the one at monument e/b would never pick up a circle number just used to give ? ? ? as the number but it was decommisioned about 7 years ago as tom states They tried one of these on the Picc in the late '60s. It began with a man getting in the cab on a random train at Earls Ct EB. He had a train number set in a rack and held it up against the nearside cab window as you left the station. A reader was fixed to the tunnel wall just inside the tunnel and it was supposed to pick up the number and transmit it to the regulating room. The man got in the cab with me one day. "It'll never work today." I said, "Why?" says he. "It's raining out there." I said, "And the light will break up with all the water on the side window." Later they fitted all Picc trains with side number racks. This was useful for staff but the readers weren't up to it and they eventually dropped the whole idea. We heard it was because the readers couldn't read the number in wet weather. |
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mrfs42
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Post by mrfs42 on Oct 2, 2007 21:20:47 GMT
The light that illuminates as the train approaches sounds like the "tripcock tester" visual. All four platforms at Earl's Court have one. Aha! Should have realised - when I typed the question this morning I was in Canterbury and away from the piles of LT paperwork - now I'm at home in Wales and I've looked at the appropriate peril I realise that I was quite a duffer for asking that question.  As ever, thank-you to all the other respondents for answering my query. |
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Deleted
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Post by Deleted on Oct 3, 2007 18:39:06 GMT
The illuminated A as described would be a semi-automatic area which is put in to automatic working. If the signal remains at danger T/Ops should treat it as an automatic signal.
The illuminated M would be at places with a cross platform interchange. At Finchley Road the Met platform has a 'J' to indicate that a jubilee line train is approaching the adjacent platform, and the Jubilee has an illuminated 'M'
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mrfs42
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Post by mrfs42 on Oct 3, 2007 19:23:12 GMT
The illuminated A as described would be a semi-automatic area which is put in to automatic working. If the signal remains at danger T/Ops should treat it as an automatic signal. <wanders off thinking about separate feeds to the 'A' light that are independent of aspect proving> The illuminated M would be at places with a cross platform interchange. At Finchley Road the Met platform has a 'J' to indicate that a jubilee line train is approaching the adjacent platform, and the Jubilee has an illuminated 'M' Just as I suspected! Thank-you very much for confirming my suspicions. ;D ;D
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Tom
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Post by Tom on Oct 3, 2007 21:20:14 GMT
The illuminated A as described would be a semi-automatic area which is put in to automatic working. If the signal remains at danger T/Ops should treat it as an automatic signal. <wanders off thinking about separate feeds to the 'A' light that are independent of aspect proving> Big fuse, lots of king lever reverse bands. I'm sure we've still got some example circuits at work. |
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mrfs42
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Post by mrfs42 on Oct 3, 2007 22:32:49 GMT
Big fuse, lots of king lever reverse bands. I'm sure we've still got some example circuits at work. And possibly some places where most of the wiring still exists. |
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