Deleted
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Post by Deleted on Feb 16, 2014 9:52:47 GMT
I was on the jubilee line last night and when the train left every station you could hear this wonderful whirling.
2 questions,
What is it?
Is it only n the jubilee line?
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mrfs42
71E25683904T 172E6538094T
Big Hair Day
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Post by mrfs42 on Feb 16, 2014 12:51:36 GMT
Gate thyristors or similar in the traction package.
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Post by t697 on Feb 20, 2014 19:04:04 GMT
Whirling or whirring?
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rincew1nd
Administrator
Junior Under-wizzard of quiz
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Post by rincew1nd on Feb 20, 2014 21:25:03 GMT
"...and always twirling, twirling, twirling...."
- Monty Burns.
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Deleted
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Post by Deleted on Feb 21, 2014 0:47:29 GMT
Jubilee Line trains are the only ones with GTO controlled AC traction motors. I believe Northern Line are IGBT controlled AC motors, as are every other new stock delivered since then. All others older trains currently in service were DC motors with camshaft control as far as I know.
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Post by domh245 on Feb 21, 2014 9:37:55 GMT
Jubilee Line trains are the only ones with GTO controlled AC traction motors. I believe Northern Line are IGBT controlled AC motors, as are every other new stock delivered since then. All others older trains currently in service were DC motors with camshaft control as far as I know. 92 stock have GTO control, but I think they control DC motors. If you listen to them, there is a whining noise at a constant pitch at lower speeds which isn't present on camshaft stock |
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Deleted
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Post by Deleted on Feb 21, 2014 11:18:16 GMT
Jubilee Line trains are the only ones with GTO controlled AC traction motors. I believe Northern Line are IGBT controlled AC motors, as are every other new stock delivered since then. All others older trains currently in service were DC motors with camshaft control as far as I know. 92 stock have GTO control, but I think they control DC motors. If you listen to them, there is a whining noise at a constant pitch at lower speeds which isn't present on camshaft stock Didn't take me much research to find that you are spot on - 92 tube stock has GTO controlled DC motors. |
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Deleted
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Post by Deleted on Mar 17, 2014 22:07:37 GMT
Do you mean this noise? I googled it a few years back as i wondered why only the jubilee line trains made that noise.
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Deleted
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Post by Deleted on Mar 17, 2014 22:39:46 GMT
That sound is way better then the 96ts sound
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Deleted
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Post by Deleted on Mar 18, 2014 2:13:36 GMT
Gate Thyristors are very old technology now I remember working with them in the 1970's!
XF
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Post by norbitonflyer on Mar 18, 2014 11:11:12 GMT
Gate Thyristors are very old technology now I remember working with them in the 1970's! XF Useful explanation of how various types of traction equipment, including GTOs, work www.twoof.freeserve.co.uk/TRACTION3.htm |
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class411
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Post by class411 on Mar 18, 2014 12:17:54 GMT
Gate Thyristors are very old technology now I remember working with them in the 1970's! XF Useful explanation of how various types of traction equipment, including GTOs, work www.twoof.freeserve.co.uk/TRACTION3.htmExcellent page. That has filled several gaps in my knowledge. Thanks a lot for the link. |
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Post by t697 on Mar 19, 2014 18:34:56 GMT
Gate Thyristors are very old technology now I remember working with them in the 1970's! XF To be fair, the devices on 96TS are Gate Turn Off Thyristors. Compared to the '70s devices these as the name suggests can be turned off as well as on at the gate and don't need commutation circuits on the power side. This makes their application simpler and more efficient in power, weight and equipment complexity. They have been overtaken by IGBTs, but have proved very robust on 96TS, even if the inverter is rather noisy acoustically. Some quite like it as we've seen on here! |
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Deleted
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Post by Deleted on Mar 26, 2014 11:29:17 GMT
Some great info here. the fundamental reason the 96TS have the GTO (and that rather nice sound) is because the 96TS was bought for lowest initial cost as part of the extension project.
Comparatively, the 95TS on the northern line was built for lower maintenance costs.
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Post by t697 on Mar 28, 2014 19:40:30 GMT
Some great info here. the fundamental reason the 96TS have the GTO (and that rather nice sound) is because the 96TS was bought for lowest initial cost as part of the extension project. Comparatively, the 95TS on the northern line was built for lower maintenance costs. Interesting, my recollection is somewhat different. 96TS was earlier than 95TS of course and Alstom were not ready to use IGBT technology at that point, so 96TS got GTOs and they have proved very robust and reliable and don't need invasive maintenance. They are on big naturally cooled heatsinks and are not fan cooled. You're correct that 95TS being leased including maintenance incentivised minimising whole life costs. IGBT technology was then ready to use and Alstom selected it. The devices needed forced cooling for technical reasons and this leaves a burden of filter cleaning and no doubt occasional fan motor overhaul. Which is better? I doubt we'll get a clear cost analysis on here.  |
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North End
Beneath Newington Causeway
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Post by North End on Mar 28, 2014 21:06:05 GMT
Some great info here. the fundamental reason the 96TS have the GTO (and that rather nice sound) is because the 96TS was bought for lowest initial cost as part of the extension project. Comparatively, the 95TS on the northern line was built for lower maintenance costs. Interesting, my recollection is somewhat different. 96TS was earlier than 95TS of course and Alstom were not ready to use IGBT technology at that point, so 96TS got GTOs and they have proved very robust and reliable and don't need invasive maintenance. They are on big naturally cooled heatsinks and are not fan cooled. You're correct that 95TS being leased including maintenance incentivised minimising whole life costs. IGBT technology was then ready to use and Alstom selected it. The devices needed forced cooling for technical reasons and this leaves a burden of filter cleaning and no doubt occasional fan motor overhaul. Which is better? I doubt we'll get a clear cost analysis on here. Definitely correct - my recollection is the IGBT traction package was not ready by the time the 96 stock design was finalised, the 95 stock followed later and was able to take advantage of the latest technology. Remember that the 96 stock was specified for the JLE, which was originally intended to open in Spring 1998. I believe the 95 stock got the earlier designation was because there had long been proposals for a '95 stock' to replace the Northern Line fleet, and it was decided that as this had long been earmarked then this would be used, even if it was slightly misleading. Interestingly, many people inside LUL & TFL believe the Jubilee Line fleet is the newer of the two -- having said that in the event the last trains of both fleets entered service more or less around the same time. According to the latest Modern Railways, it is suggested that if additional trains are built for the Jubilee Line, they will incorporate an IGBT traction package, and in the process the remainder of the Jubilee fleet would be so converted. Note that the IGBT 'Onix' traction package on the 95 stock is, I believe, virtually identical to that used on the class 458 / 460 trains, which were built in roughly the same era. By comparison my understanding is the package fitted on the 96 stock is technically similar to that found on the class 465/2, 466 and 365 trains, though I'm open to correction on that. |
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