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Post by Tubeboy on Aug 19, 2006 22:02:59 GMT
Has their design/operation altered much over the years?
I have heard that the ones at Barons Court, Hounslow and West Hampstead have never been used. If that is the case, how do lu know they are functioning properly? Are they tested every now and again in engineering hours?
Admins, move to another board if appropriate.
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Deleted
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Post by Deleted on Aug 19, 2006 22:05:19 GMT
You've got a point there, TB... If they are smashed buy an 'out of gauge' train, it's supposed to throw signals to danger, yeah? So, if they have never been used... and I'm surprised they havent been vandalised...
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Colin
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Post by Colin on Aug 19, 2006 23:06:08 GMT
AFAIK all of them have been changed from mercury to a special silver paint - so they are not as old as you may think. As they are part of the signalling system, they will be subject to some form of testing at some time or other........
One for Tom or aetearlscourt...............
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Deleted
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Post by Deleted on Aug 20, 2006 2:20:42 GMT
The ones at West Hampstead were smashed during an engineering possession, with predictable results for the Jubilee Line service the following Monday - stephenk can verify that those particular tubes do work COLIN is right about the tubes being painted with conductive silver paint instead of mercury. The three tubes all work by returning their associated signal to danger (X412a for Hounslow West, X647c for Barons Court, and JD11 for West Hampstead). What I want to know is if they also cut off the traction current (as has been postulated by some).
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Deleted
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Post by Deleted on Aug 20, 2006 5:53:29 GMT
the ones at barons court have been smashed quite a few times and even been by passed due to lack of spares they do not switch off the traction current (well not barons court) the ones at barons court picked up a special relay (zr z= special r = relay) this is then in the signal selection of the X signal so if this relay dropped then the signal remains at danger
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Phil
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Post by Phil on Aug 20, 2006 7:27:11 GMT
Since the glass tube is a fail-safe device (exactly like a conventional fuse is, break the contact to cut the current) it would not need testing. Presumably the rest of the circuitry can be tested just by removing one of the wires to the tube to simulate breakage.
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Post by agoodcuppa on Aug 20, 2006 7:29:21 GMT
What I want to know is if they also cut off the traction current. Traction current is unaffected when the tubes are broken. They simply return the associated "X" signal to danger which stops the train.
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Oracle
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Post by Oracle on Aug 20, 2006 11:19:59 GMT
What amazes me is that the tubes are still there east of Hounslow West and yet SSL stock is I gather banned from west of Northfields because of the rebuilt bridges over Kingsley Road and Lampton Road [HOUNSLOW EAST and CENTRAL respectively] which for some reason were built to tube gauge? The last SSL train I know of that reversed at Central was the D78 Tour in 1980 *as mentioned before. If I am wrong shoot me on this, but any SSL train would have come to grief some distance away from the hoops if I am correct about the bridges..unless they are retained for safety reasons during engineering possessions?
* I am certain that neither the CO/COP Stock and R Stock farewells reversed at Central from memory and evidence found over online.
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Post by citysig on Aug 20, 2006 18:40:04 GMT
The ones at West Hampstead were smashed during an engineering possession, with predictable results for the Jubilee Line service the following Monday - stephenk can verify that those particular tubes do work Ahem. Seeing as the Jubilee Line between the crossover just north of Neasden and the crossover just south of West Hampstead (which follows JD11) is still passed for surface stock use, you may want to revise the location stated for the tubes If they have moved them further north to the location you state, it gives an easier opportunity to test them. Next time the Met is shut down I will be first to suggest we divert at least one train via the Jub ;D
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Post by Tomcakes on Aug 20, 2006 19:16:42 GMT
Wouldn't testing be pretty pointless?
You smash one set of tubes.
Then you need to install a fresh set.
How do you know the fresh set work properly? Ought to test them!
You smash the second set of tubes.
ad infinitum
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Oracle
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Post by Oracle on Aug 20, 2006 19:26:18 GMT
Forgive this poor soul but I thought the SSL trains were banned from using the Jubilee lines? The C Stock did of course run late night/early morning to/from Neasden. I did ask this before as there used to be a cross-over Met>Jubilee south of Finchley Road. I know that this query was answered not that long ago but I have forgotten the answer! Or is there just one permisible section? I was given to understand that the 'ban' was because of signalling differences although I am sure that is not the case.
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Post by trc666 on Aug 20, 2006 20:52:05 GMT
In theory, Mets could run along the southbound local from Wembley Park to Finchley Road (exclusive) and Jubilees could run along the southbound fast from Wembley Park to Finchley Road but would have to be reversed at Finchley Road, and would only be able to call at Neasden and Willesden Green. Met services could call additionally at Neasden and Willesden Green in both directions (or all stations if on the southbound local). Do Met drivers have route knowledge for the southbound local?
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solidbond
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Post by solidbond on Aug 20, 2006 21:07:07 GMT
Certainly until the mid 90's, possibly later, C stock ran over the Jubilee both NB and SB between Wembley Park and West Hampstead, crossing between the lines NORTH of Finchley Road. The Surface Stock detectors were positioned on the approach to Finchley Road Jubilee SB line. I do remember that one of the tubes was broken by the jib of a crane one weekend, and they had to bypass it for a while until a replacement one could be located
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Post by trc666 on Aug 20, 2006 22:51:14 GMT
In answer to Oracle's question, there was a connection from the northbound fast to the northbound local just north of Finchley Road station (Mets could cross to the local, but Jubilees couldn't cross to the fast) , but has been partially removed now. The northbound fast is completely isolated from the local lines until Wembley Park.
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Deleted
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Post by Deleted on Aug 20, 2006 23:24:52 GMT
The ones at West Hampstead were smashed during an engineering possession, with predictable results for the Jubilee Line service the following Monday - stephenk can verify that those particular tubes do work Ahem. Seeing as the Jubilee Line between the crossover just north of Neasden and the crossover just south of West Hampstead (which follows JD11) is still passed for surface stock use, you may want to revise the location stated for the tubes Blargh. You only notice the egg on your face when it starts to stink JD11's glass tubes are of course at the s/b Jubilee platform tailwall at Finchley Road. If they have moved them further north to the location you state, it gives an easier opportunity to test them. Next time the Met is shut down I will be first to suggest we divert at least one train via the Jub ;D I don't doubt it!
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Post by citysig on Aug 22, 2006 15:32:13 GMT
Forgive this poor soul but I thought the SSL trains were banned from using the Jubilee lines? Not banned, just shall we say, obstructed by the politics that surrounds the railway these days. Tends to get into the pointwork and makes it very difficult to throw them until after a big conflab between the Met and Jub controllers - which generally ends in one line or the other storming off in a huff. The last time I recall sending a Met down the Jub it had taken 10 minutes for either controller to make a decision. So I made it for them. By the time they had decided the train was back on its own soil.
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Deleted
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Post by Deleted on Aug 22, 2006 15:51:05 GMT
I also am led to beleive that there must have been a similar device at Leyton to stop the BR steam stock from the Epping - Ongar branch, that went to Seven Kings/Ilford etc, running into the tunnels on a westbound working.
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Post by Tubeboy on Aug 22, 2006 17:09:08 GMT
If ATO is correct, then what about Newbury Park?
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DWS
every second count's
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Post by DWS on Aug 22, 2006 17:26:48 GMT
Leyton and Newbury Park had Electric Train Detectors to stop steam trains from going down the tube tunnels.
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Deleted
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Post by Deleted on Aug 22, 2006 17:29:09 GMT
And I guess that was linked to a length of dummy juice rail...? I'm sure I read an article on this ages ago, but can't remember where it was....
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DWS
every second count's
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Post by DWS on Aug 22, 2006 17:37:16 GMT
And I guess that was linked to a length of dummy juice rail...? I'm sure I read an article on this ages ago, but can't remember where it was.... Yes thats how they work, the steam trains would not make the short bit of + rail live and the Starting signal for the Tube route would not clear.
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Deleted
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Post by Deleted on Aug 22, 2006 17:40:22 GMT
So at a guess any steamer would have been required to run at restricted speed when running in between the tube trains?
ETD's... It's all starting to come back to me now....
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DWS
every second count's
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Post by DWS on Aug 22, 2006 17:47:42 GMT
So at a guess any steamer would have been required to run at restricted speed when running in between the tube trains? ETD's... It's all starting to come back to me now.... Why would the steam trains have to run at restricted speeds, the locos had tripcocks fitted.
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Post by mandgc on Aug 22, 2006 23:38:45 GMT
Restricted Speed for Non Electric Trains.
The signalling was designed for Electric train Braking distances and other trains, usually with longer Braking distances, were provided with the Disc Distant Signals. These indicated when all signals through a station were at 'Clear' enabling the non-stopping train to proceed at maximum allowed speed. If the train passed a Disc Distant at Caution the Driver was required to continue prepared to stop at any signal that may be at Danger.
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Colin
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Post by Colin on Aug 23, 2006 2:07:35 GMT
And I guess that was linked to a length of dummy juice rail...? I'm sure I read an article on this ages ago, but can't remember where it was.... Could it have been THIS?EDIT: Actually THIS OLD BABY is probably the one you are referring to ;D
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Deleted
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Post by Deleted on Aug 23, 2006 10:42:50 GMT
Thats it Colin!
Nice one!
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