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Post by will on Nov 19, 2014 16:06:18 GMT
Anyone know the cause of the failure? it first occurred at 1AM yesterday and clearly didn't get resolved in engineering hours and causes a suspension on the Piccadilly line today of 8 hours and the District !!!!
I've heard they have "scanning" issues in the Acton Town area, what does this mean?
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Deleted
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Post by Deleted on Nov 19, 2014 17:01:44 GMT
600v Signal Main Box filled with water and decided to go bang
Scanning is completely different its a form of transmission from site to the control room at Earls Court them issues are now fixed.
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rincew1nd
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Junior Under-wizzard of quiz
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Post by rincew1nd on Nov 21, 2014 1:25:14 GMT
IIUC scanning is automated equipment at the lineside reading the TD displayed on the front of the train and populating the signalling system accordingly. This is why all LU trains display the TD on the front end.
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Post by Harsig on Nov 21, 2014 7:19:13 GMT
IIUC scanning is automated equipment at the lineside reading the TD displayed on the front of the train and populating the signalling system accordingly. This is why all LU trains display the TD on the front end. I'm afraid you're barking up the wrong tree there. Scanning is the underground's name for the system for transmitting indications from the local signalling to the remote signal control room using a minimum number of wires. These would include things like point and signal indications and track circuit indications. If I've understood it correctly it uses a form of time division multiplexing to transmit multiple indications over a single (pair?) wire. When faults develop with this system all sorts of spurious indications are shown to the signalman. |
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rincew1nd
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Post by rincew1nd on Nov 21, 2014 9:44:12 GMT
Thanks for the correction! Just goes to show a little knowledge is a dangerous thing and that I firmly belong in the amateur camp!
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Post by Deleted on Nov 21, 2014 11:15:42 GMT
IIUC scanning is automated equipment at the lineside reading the TD displayed on the front of the train and populating the signalling system accordingly. This is why all LU trains display the TD on the front end. I'm afraid you're barking up the wrong tree there. Scanning is the underground's name for the system for transmitting indications from the local signalling to the remote signal control room using a minimum number of wires. These would include things like point and signal indications and track circuit indications. If I've understood it correctly it uses a form of time division multiplexing to transmit multiple indications over a single (pair?) wire. When faults develop with this system all sorts of spurious indications are shown to the signalman. That is correct ask any signal op at Earls Court recently as the Acton area was more like Blackpool at this time of year at times |
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