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Post by londonstuff on Jan 12, 2008 16:02:52 GMT
Hi all, Where does the noise come from on Jubilee line trains when they start moving - it seems unique to the Jubilee trains although Northern line trains seem to make a different noise. I presume it's something to do with the engines? It's towards the end of this clip: uk.youtube.com/watch?v=AGxZTedMgrsThanks  |
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metman
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Post by metman on Jan 12, 2008 16:28:10 GMT
It's a horrible noise too-both stock imo!
It's the motors that make the noise-it is a similar noise to the Networkers running on the (Kent Link) Southeastern services.
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Post by Alight on Jan 12, 2008 16:29:12 GMT
TBH i dont know much about engines But I believe it is to do with the engine.
The Northern is different I recon it doesn't have the same novelty noise as their aim was to have more quieter trains and altho the Jubs sound fantastic, they aren't the most quietist! Just my opinion guys before Im aimed with any abuse! ;D
The Central actually, mjw4849 sound very similar to the Jubilee, not as exaggerated though. More like a vaccum cleaner in take off!
Ive seen many youtube comments describing the "break down" of the 96stocks sounding like Dath Vader saying "Noooooo"
On take off they sound rather tardisy hence why I call them the "tardis trains".
Overall the Jubilee do sound very futuristic and I love it!
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Post by c5 on Jan 12, 2008 16:30:05 GMT
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Post by Tubeboy on Jan 12, 2008 16:32:43 GMT
The Northern are like an updated version of the Jubilee stock.
I prefer the motor noise on the Northern stock, Jubilee is ok though.
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Deleted
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Post by Deleted on Jan 12, 2008 16:33:44 GMT
Where does the noise come from on Jubilee line trains when they start moving - it seems unique to the Jubilee trains although Northern line trains seem to make a different noise. I presume it's something to do with the engines? Our very own DD Forum contributor johnb wrote the following wikipedia entry explaining the differences between the 95 and 96 traction packages: en.wikipedia.org/wiki/London_Underground_1996_Stock#Traction_control |
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metman
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Post by metman on Jan 12, 2008 16:36:32 GMT
Can't beat DC motors with PCM and line breakers!!
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Post by edwin on Jan 12, 2008 17:53:31 GMT
I heard that the new Victoria line trains sound like the Heathrow Express...
The Central line's trains sound similar to Class 319 Stock on the Thameslink line, were they built around the same time?
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Deleted
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Post by Deleted on Jan 12, 2008 18:11:20 GMT
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Deleted
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Post by Deleted on Jan 12, 2008 22:36:33 GMT
I love the noise and I know theres a few fans of it.
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Post by antharro on Jan 12, 2008 22:43:40 GMT
I like the sound of the Jubilee trains, especially when the T/Op leaves the motors in until the train's almost stopped so you can hear all three ""gears"". (Yes, I know there's no gears). The sound isn't the actual motors themselves, it's the circuitry that converts the DC power into three phase AC.
To quote from the Wikipedia article:
"The GTO thyristor [ed: part of the circuity used on the inverter that drives the motor] used on 1996 stock achieves this by 'chopping' out short pulses of current, creating the characteristic audible whine associated with the stock and with the Class 465 networker trains that share its traction control system. The noise timbre changes as the pulse length changes. The noise is produced by the oxygen in the air vibrating as the magnetic field changes (oxygen is magnetic whereas nitrogen is not)."
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Deleted
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Post by Deleted on Jan 15, 2008 9:26:08 GMT
I like the sound of the Jubilee trains, especially when the T/Op leaves the motors in until the train's almost stopped so you can hear all three ""gears"". (Yes, I know there's no gears). The sound isn't the actual motors themselves, it's the circuitry that converts the DC power into three phase AC. To quote from the Wikipedia article: "The noise is produced by the oxygen in the air vibrating as the magnetic field changes (oxygen is magnetic whereas nitrogen is not)." Sorry, but this is nonsense. Neither oxygen nor nitrogen are magnetic. The noise comes from the motors themselves, as pulses of electricity go through them. |
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Deleted
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Post by Deleted on Jan 15, 2008 9:29:41 GMT
Thats got to be a new one on me! If oxygen was to be magnetic, why doesn't everything that has magnetic properties,s tick to 'it'?
And quite how that would happen, is beyond me.
The traction package on the 1996 stock, is actually an older design than that on the 1995 stock.
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Ben
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Post by Ben on Jan 15, 2008 19:30:01 GMT
Both oxygen and nitrogen are magnetic, but not in the common sense of ferromagnetism, which is what normal magnets experience, and neither do they experience the same type of magnetism.
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mrfs42
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Post by mrfs42 on Jan 15, 2008 19:38:49 GMT
Indeed, both Oxygen and Nitrogen are utilised in the production/excecution of Ferrofluidics. A fair few audio speakers have ferrofluidic cores - in essence the mechanism of propagation is the same as the Jubilee whine.  |
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Deleted
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Post by Deleted on Jan 15, 2008 19:51:06 GMT
A fair few audio speakers have ferrofluidic cores Isn't the ferofluid just a lubricant/coolant for the voice coil? Back on topic... I thought (could be wrong) that the sound was produced by the motor windings vibrating as the magnetic field oscillates with the ac current. Have the motors got louder with age? |
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Post by superteacher on Jan 15, 2008 20:17:39 GMT
I love the 96TS "gear" noise - one of the most distinctive sounding trains around at the moment. But I agree - nothing like the PCM doing its 9 notches, then the rush of air as it moves from series into parallel! I also think that the clunk on the 67/72 TS as it pulls away is distinctive.
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mrfs42
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Post by mrfs42 on Jan 16, 2008 0:58:58 GMT
A fair few audio speakers have ferrofluidic cores Isn't the ferofluid just a lubricant/coolant for the voice coil? Quite possibly, I'm remembering back through about 17 years of uninterested memory. [ Back on topic... I thought (could be wrong) that the sound was produced by the motor windings vibrating as the magnetic field oscillates with the ac current. Have the motors got louder with age? The motors have got louder with use, not age. Though the body of the unit has worked loose at the joints so working as a better sounding board. |
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Deleted
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Post by Deleted on Jan 16, 2008 8:31:38 GMT
Indeed, both Oxygen and Nitrogen are utilised in the production/excecution of Ferrofluidics. A fair few audio speakers have ferrofluidic cores - in essence the mechanism of propagation is the same as the Jubilee whine. Well, the "ferro" part of "ferrofluidic" means "iron", and it is this that provides the magnetism. Iron is the only naturally-occurring material that displays magnetism. |
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Deleted
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Post by Deleted on Jan 16, 2008 10:00:51 GMT
Iron is the only naturally-occurring material that displays magnetism. No it isn't - nor is it the only naturally-occurring material that displays ferromagnetism, If we're talking elements alone, cobalt, nickel, gadolinium and dysprosium are all ferromagnetic as well, though gadolinium is only ferromagnetic on cool days, and dysprosium needs to be below 88 Kelvin. There exist other magnetic states, and oxygen, at least as a liquid, does exhibit one of them. |
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Oracle
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Post by Oracle on Jan 16, 2008 10:09:36 GMT
Isn't Lodestone, an iron compound, naturally magnetic?
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mrfs42
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Post by mrfs42 on Jan 16, 2008 20:57:12 GMT
Isn't Lodestone, an iron compound, naturally magnetic? Yes, used by the Greeks [1], Vikings and seafaring Mughals to navigate with! Usually suspended from a piece of thread it would align on a magnetic North/South axis. Coupled with the excellent astronomy of the Hindus, lodestone was an invaluable aid to navigation. [1] although I seem to remember from interminable Latin and Greek classes that those seafarers were very reluctant to stray far from the sight of land. |
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