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Post by Deleted on Jul 20, 2015 13:32:17 GMT
Was travelling from Camden Road to West Brompton the other day, and during the journey three huge bangs came from above us - presumably from the pantograph. Was unusual and loud enough to allow eye contact with other travelers.
Any idea what might've caused this? Haven't come across it before.
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Post by dazz285 on Jul 20, 2015 14:01:46 GMT
Possibly when the train goes through the neutral sections at Camden Rd & at North Pole.
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Post by Deleted on Jul 20, 2015 14:04:52 GMT
What would it be that makes the noise, in that case?
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Post by patstonuk on Jul 20, 2015 14:05:09 GMT
All the Electrostar AC family have noisy circuit breakers, operating at neutral sections as dazz285 says.
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Post by Deleted on Jul 20, 2015 14:22:01 GMT
Ta
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Post by brigham on Jul 20, 2015 14:45:07 GMT
Is this a result of crossing section gaps with the controller 'on'?
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Post by dazz285 on Jul 20, 2015 14:50:40 GMT
No just noisy circuit breakers, as patstonuk says.
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Post by norbitonflyer on Jul 20, 2015 15:44:08 GMT
You'd get a very big bang if the pantograph was still up at West Brompton - the ohle runs out shortly before Shepherds Bush!
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Post by Deleted on Jul 22, 2015 16:01:41 GMT
Was travelling from Camden Road to West Brompton the other day, and during the journey three huge bangs came from above us - presumably from the pantograph. Was unusual and loud enough to allow eye contact with other travelers. Any idea what might've caused this? Haven't come across it before. I heard a similar banging sound when approaching Willesden Junction High Level it turn a few heads.
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Post by Deleted on Sept 10, 2015 22:51:13 GMT
The bang you hear in the PTOS is the Vacuum Circuit Breaker (or VCB) operating. This is operated remotely by a track side magnet which opens the VCB so that when the pantograph passes between different current sections it doesn't draw an arc which could cause alsorts of problems. They are noisy because of the speed they operate at, they need to be quick because their operation is based on a track speed of 75mph. I know, the 378's don't reach that speed in service, but someone in Derby used a slide rule to work these things out and then gave the contract to Fisher Price to make the VCB's
Hope this helps
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Post by Deleted on Sept 10, 2015 23:08:46 GMT
The bang you hear in the PTOS is the Vacuum Circuit Breaker (or VCB) operating. This is operated remotely by a track side magnet which opens the VCB so that when the pantograph passes between different current sections it doesn't draw an arc which could cause alsorts of problems. They are noisy because of the speed they operate at, they need to be quick because their operation is based on a track speed of 75mph. I know, the 378's don't reach that speed in service, but someone in Derby used a slide rule to work these things out and then gave the contract to Fisher Price to make the VCB's Hope this helps Very much so, thanks Would you be able to just clarify for us what you mean by PTOS?
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Post by Deleted on Sept 10, 2015 23:40:40 GMT
The bang you hear in the PTOS is the Vacuum Circuit Breaker (or VCB) operating. This is operated remotely by a track side magnet which opens the VCB so that when the pantograph passes between different current sections it doesn't draw an arc which could cause alsorts of problems. They are noisy because of the speed they operate at, they need to be quick because their operation is based on a track speed of 75mph. I know, the 378's don't reach that speed in service, but someone in Derby used a slide rule to work these things out and then gave the contract to Fisher Price to make the VCB's Hope this helps Very much so, thanks Would you be able to just clarify for us what you mean by PTOS? Pantograph - car with pantograph Trailer - trailer car Open - open type of interior Second - second/standard class I think that's it anyway!
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Post by domh245 on Sept 10, 2015 23:51:40 GMT
Or in laymans terms, the car with the big pointy thing on the top! It is also worth noting that neutral sections are used to prevent the AC phases from the different feeder stations interfering and wreaking havoc, or to create isolated branches (á la rail gap) in places where current may have to be withdrawn but you don't want to paralyse the rest of the line - typically next to airports where in the event of an emergency landing, signals are replaced to danger and the power is cut.
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Post by whistlekiller2000 on Sept 11, 2015 6:33:38 GMT
The bang you hear in the PTOS is the Vacuum Circuit Breaker (or VCB) operating. This is operated remotely by a track side magnet which opens the VCB so that when the pantograph passes between different current sections it doesn't draw an arc which could cause alsorts of problems. They are noisy because of the speed they operate at, they need to be quick because their operation is based on a track speed of 75mph. I know, the 378's don't reach that speed in service, but someone in Derby used a slide rule to work these things out and then gave the contract to Fisher Price to make the VCB's Hope this helps Not bad for starters BBB! Welcome to the forum!
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Post by Deleted on Sept 14, 2015 2:29:05 GMT
Thanks for the welcome Whistlekiller2000
Sorry if I confused anyone with the term of PTOS. The electrostar fleet have a seies of acronyms for the different cars which are as follows:-
378 class (London Overground stock) DMOS, Driving (or driven) Motor, Open, Saloon MOS, Motor, Open, Saloon PTOS Pantograph, Trailer (no motors on this car) Open, Saloon
The DMOS' will also be termed A or B, so its not unusual to hear reference to DMOSA or DMOSB. The individual coach number will be the way to tell them apart
357 class (C2C stock) Exactly the same as the above description except the PTOS is actually a PTOSL Pantograph, Trailer (no motors on this car) Open, Saloon, Lavatory (or Friday night vomit collection device)
Hope this clears any confussion
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Post by Deleted on Sept 14, 2015 2:32:11 GMT
No need to apologise - that's very helpful, thanks! And a warm welcome from me, too Settle down, help yourself to tea from the teapot and make yourself at home
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