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Post by uzairjubilee on Aug 21, 2008 18:00:43 GMT
The Victoria Line is having minor delays due to a faulty track at Victoria.
What track is actually affected?
Accoring to the Departure Boards on the TfL website, a couple of trains from Walthamstow are being turned back early at Victoria. So are they usin the crossover north of the station or the sidings?
Are any trains terminating at Warren Street or anywhere else?
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Post by superteacher on Aug 21, 2008 18:53:01 GMT
The Victoria Line is having minor delays due to a faulty track at Victoria. What track is actually affected? Accoring to the Departure Boards on the TfL website, a couple of trains from Walthamstow are being turned back early at Victoria. So are they usin the crossover north of the station or the sidings? Are any trains terminating at Warren Street or anywhere else? They are running a special timetable - not sure what track is affected. Victoria reversers are normally via the sidings. Wouldn't think Warren Street is being used to reverse trains - that's only usually used when the service is up the wall! |
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Post by Tubeboy on Aug 21, 2008 21:44:10 GMT
Its a points problem, No 13 at Victoria is faulty. So there is a TSR of 10 Mph going over them, hence the delays.
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mrfs42
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Post by mrfs42 on Aug 22, 2008 0:36:48 GMT
Its a points problem, No 13 at Victoria is faulty. So there is a TSR of 10 Mph going over them, hence the delays. 13? Forgive me for being utterly naive; but for the majority of moves (as there are practically nil 22 road reversers and precious few 23 road reversers) these point are both in normal lie and trailing. Is the TSR (Temporary Speed Limit) in place due to loss of detection and consequent securing? |
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Post by Tubeboy on Aug 22, 2008 0:41:25 GMT
The document just states that there is a 60mm missing chunk from the crossing nose on 13 points. I am not technical, so dont ask me to explain any of that!  |
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mrfs42
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Post by mrfs42 on Aug 22, 2008 0:44:01 GMT
In that case, a 10mph slack seems reasonable. |
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Post by railtechnician on Aug 22, 2008 1:31:24 GMT
The document just states that there is a 60mm missing chunk from the crossing nose on 13 points. I am not technical, so dont ask me to explain any of that! A crossing made of rails rather than being cast as a unit comprises two wing rails a point rail and a closure rail. The point and closure rails form a 'V' which sits within the two wing rails. The point of the 'V' is the nose of the crossing. the loss of 60mm (just over two inches) of nose is significant enough to warrant a speed restriction to obviate any possibility of a derailment by negotiating the points at normal speed. It is possible that at normal speed a 'joggled' axle wheel could hit the broken nose and jump whereas the pointed nose would properly guide the wheel onto the rail. |
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Post by Tubeboy on Aug 22, 2008 1:39:44 GMT
Thanks for the easy explanation, its appreciated.
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Post by railtechnician on Aug 22, 2008 8:39:44 GMT
Thanks for the easy explanation, its appreciated. No problem, I referred to a crossing made of rails as it was easiest to explain but in a cast crossing the same problem arises if the point of the solid 'V' is badly worn or broken. |
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Deleted
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Post by Deleted on Aug 22, 2008 11:42:48 GMT
Is this weakness why modern fixed crossing noses are made of super-hard alloys containing rare metals such as titanium? I had heard that new metallurgical techniques had resulted in crossing noses that were significantly stronger and more durable, especially for very narrow noses (<45 degrees, IIRC).
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Post by railtechnician on Aug 22, 2008 13:41:35 GMT
Is this weakness why modern fixed crossing noses are made of super-hard alloys containing rare metals such as titanium? I had heard that new metallurgical techniques had resulted in crossing noses that were significantly stronger and more durable, especially for very narrow noses (<45 degrees, IIRC). Yes I expect that is the case, the cast crossing seems to be replacing the traditional one constructed of rails. Obviously some parts of the permanent way are weaker than others, crossing noses and the tips of point blades are particularly prone to wear and fracture so any process that can produce more durable parts is a winner. I think the manganese crossing was the first cast type that I came across. We had some manganese rails too and drilling them for track connections was blunting the HSS drill bits in our bikes (drilling machines, we were soon issued with suitable drill bits with extra hard tips which ISTR were made of tungsten. |
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