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Post by orienteer on Oct 7, 2005 16:19:56 GMT
I usually travel on the DM cars on the Met, to avoid the incredibly noisy compressors on the trailer cars!
Sometimes I notice that the cars are not motoring: there are no notching or motor sounds. Then partway through the journey, they sometimes start to motor again. Are drivers conscious of this happening, so they can report a fault?
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Post by trainopd78 on Oct 7, 2005 21:55:48 GMT
As a driver, I can always tell when a motor is out as the train will feel sluggish, and on a C stock, you can use the rail gaps to ascertain which one is out. On a D stock you can use the TMS to give yourself an indirect indication, but thats far from foolproof.
Sometimes, by tripping and resetting the overloads, or by giving a very small notch back (with the traction test switch operated so you don't move), you may be able to bring the dud motor back to life. There are other ways too depending on stock.
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Post by q8 on Oct 7, 2005 22:24:34 GMT
There is OR was a 'sequence plug' in the cab of all DM's that told you when a motor was not working. This used be a 'sequence indicator' in years gone by that lit up when all motors in a train reached top notch. As, more often than not, a motor did not function and drivere were taking trains out of service they took it away.
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Post by igelkotten on Oct 8, 2005 0:10:48 GMT
As a driver, I can always tell when a motor is out as the train will feel sluggish, and on a C stock, you can use the rail gaps to ascertain which one is out. On a D stock you can use the TMS to give yourself an indirect indication, but thats far from foolproof. Sometimes, by tripping and resetting the overloads, or by giving a very small notch back (with the traction test switch operated so you don't move), you may be able to bring the dud motor back to life. There are other ways too depending on stock. One trick we used to use was to look for arcs from the third rail in certain tunnel sections with crossovers or large-ish gaps in the third rail. Each arc represented a live car, so you counted the live ones until you got to a non-arcing one. And of course, sometimes you could feel from the jerks in the train which car didn't motor or brake properly. |
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Deleted
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Post by Deleted on Oct 8, 2005 0:50:54 GMT
A60's are renowned for having motors out, these trains are after all among st the oldest in the UK. Many times when I was on the Met I'd pick up a train which had a motor or two out and seemed to take forever to get going. As they now have a limited lifetime I don't see the motors getting overhauled any more, so you can expect more slow acceleration.
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Colin
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Post by Colin on Oct 8, 2005 3:02:22 GMT
I think the answer to the question orienteer was asking is:
The motors dropping out and coming in again is known as coasting - that is; when the train reaches a set speed it automatically stops motoring, then, when it slows to another set speed the motors power up again. This is perfectly normal and is in no way a fault.
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Post by orienteer on Oct 8, 2005 20:41:28 GMT
I think the answer to the question orienteer was asking is: The motors dropping out and coming in again is known as coasting - that is; when the train reaches a set speed it automatically stops motoring, then, when it slows to another set speed the motors power up again. This is perfectly normal and is in no way a fault. No, it's not coasting. The motors never work from the start. Today I was on another one, car 5117 on the 14.00 from Uxbridge to Baker Street. My question is, how do these (in the middle of the train) get noticed, and reported for repair? |
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Post by Deleted on Oct 8, 2005 21:12:00 GMT
If the driver feels the train is sluggish he will usually call for a train technician. If the technician confirms a fault then it will be dealt with on overnight maintenance. If the train is very slow or there is a risk of being gapped then the train will be changed over as soon as possible.
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Post by Deleted on Oct 8, 2005 22:48:20 GMT
Orienteer, you are indeed wise to avoid riding in trailer cars on A-stock, and that's what I do as well. They must certainly be the noisiest compressors anywhere on LUL at the moment! As Jim has said, an A60/62 with a motor car not working seems to take forever to get going. Their rate of acceleration is on the slow side anyway, having only 4 motor cars on an 8-car train as compared with 6 motor cars on 8-car 1962 tube-stock built in the same era. All rolling stock built since accelerates much faster than A-stock, even C-stock with only 3 out of 6 cars motored. And Jim may also remember some of our colleagues (not us of course!) deliberately trying to stall trains with motors out at various locations -- like coming into Harrow platform 3 from the NB local if the inner home was on....  Well the front car always goes off-juice when you stop at that signal, plus at least one other DM, so the risk is there! Sometimes one car of motors doesn't work simply because the reversers haven't thrown. Notching-up a few times alternately in forward and reverse, plus tripping and re-setting the overloads, can work wonders on elderly stock like A60s.  Strange though it may seem, things do seem to have improved a little recently, as I've not had a train with dud motors for over a month now. Bet it's the first one I pick-up tomorrow now I've said that!! ;D |
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Well the front car always goes off-juice when you stop at that signal, plus at least one other DM, so the risk is there! 
