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Post by wanstead on May 29, 2021 13:26:00 GMT
Apologies if this subject has been raised several times before. I'm wondering if the crossover just outside Piccadilly Circus is still in use? Carto Metro seems to suggest only half of it is still extant.
Is it only really used for emergencies and for engineering work? Could it in theory be used to make Piccadilly a terminus if engineering work is required on the southern part of the line? That being said, I don't think I've ever seen or heard of a Piccadilly terminator in all my years travelling on the Bakerloo!
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Post by taylor on May 29, 2021 17:52:16 GMT
Just checked the location and everything about points 10A (I believe that's the set at the W. end of SB platform 2) looks pretty serviceable, and rails do look as though they have all been used in the recent past. I'll upload a photograph if I can find directions somewhere. There are a series of what appear to be hinged plates snug against the outer switch-rail, i.e. right hand running rail approaching from Oxford Circus. (I may be using American terminology).
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DWS
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Post by DWS on May 29, 2021 17:53:54 GMT
Apologies if this subject has been raised several times before. I'm wondering if the crossover just outside Piccadilly Circus is still in use? Carto Metro seems to suggest only half of it is still extant. Is it only really used for emergencies and for engineering work? Could it in theory be used to make Piccadilly a terminus if engineering work is required on the southern part of the line? That being said, I don't think I've ever seen or heard of a Piccadilly terminator in all my years travelling on the Bakerloo! Only a single trailing crossover now, The facing crossover from the southbound line was removed many years ago. |
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Tom
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Post by Tom on May 29, 2021 21:02:26 GMT
Is it only really used for emergencies and for engineering work? Could it in theory be used to make Piccadilly a terminus if engineering work is required on the southern part of the line? That being said, I don't think I've ever seen or heard of a Piccadilly terminator in all my years travelling on the Bakerloo! I've known it to be used occasionally for engineering work (and once to reverse a train due to a service suspension) but it's not popular - the last time there was any regular service reversing there was in the 1990s when the tunnel strengthening work was going on between Embankment and Waterloo. From memory you need to stop at a different stopping mark to get the rear cab in the platform. Trains crossing over to head north have a series of five speed-controlled signals as they go over the crossover, which enforces a very restrictive 5mph speed limit, imposed after several trains have derailed there over the years. Just checked the location and everything about points 10A (I believe that's the set at the W. end of SB platform 2) looks pretty serviceable, and rails do look as though they have all been used in the recent past. I'll upload a photograph if I can find directions somewhere. There are a series of what appear to be hinged plates snug against the outer switch-rail, i.e. right hand running rail approaching from Oxford Circus. (I may be using American terminology). It's 7A, BP10 is the signal which brings you back across. The device on the LH switch rail (when looking into the crossover, RH as you approach from Oxford Circus) is an American device which is known as a 'house-top'. It's basically an extended check rail, and is a very common feature of North American metro systems.  |
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Post by superteacher on May 29, 2021 21:06:36 GMT
It’s certainly been used during service suspensions and planned engineering works. Beyond that, there are no scheduled reversers there.
Didn’t something derail on it a few years ago?
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Tom
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Post by Tom on May 29, 2021 21:09:01 GMT
Yes - a 1938 stock train in 1975, at least one 1972 stock train in the 1990s, and the former Tunnel Cleaning Train.
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North End
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Post by North End on May 29, 2021 22:13:39 GMT
It’s certainly been used during service suspensions and planned engineering works. Beyond that, there are no scheduled reversers there. Didn’t something derail on it a few years ago? As far as I can recall, not since the 1990s. There were two 72 stock derailments around that time, both incidents resulting in cars being written off. One of them was during the long-term closure south of Piccadilly Circus for tunnel works. I think that was the most recent. The speed controlled signals seem to have done the trick, as I think we can infer both of the 72 stock incidents were due to excess speed. The tunnel cleaning train incident wasn’t though, that was an issue with the train itself which became an issue on the awkward angles of the crossover. I seem to remember reversing NB to SB was banned, and may still be. Again all down to the specific issues with the crossover. |
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Post by jimbo on May 30, 2021 5:23:23 GMT
This may be the only reversing point on the line between Paddington and Lambeth North, but it is far from satisfactory for practical use. The severe speed restriction adds to the time taken for a train to reverse, reducing possible throughput. Sited at the once considered centre of the Empire, the station has seen no improvement since escalators arrived nearing a century back, and the platforms are the same as when the line opened. The narrow curving southbound platform is unsuitable to detrain passengers from a full train and take on passengers for a northbound trip. If anything, it would be better to detrain at Oxford Circus, and work empty to reverse since two platforms can be used there, and interchange works with the Victoria Line provided much more underground space there.
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Post by 100andthirty on May 30, 2021 7:07:07 GMT
Modelling showed that there was a significant risk of derailment even at the nominal speed limit of the crossover. The solution was to provide a continuous check rail though the points. This is almost unique in the UK and was cribbed from a design used on the New York Subway and seen in Coney Island overhaul works. The feature can be seen in the photo in the post above.
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DWS
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Post by DWS on May 30, 2021 7:18:05 GMT
Modelling showed that there was a significant risk of derailment even at the nominal speed limit of the crossover. The solution was to provide a continuous check rail though the points. This is almost unique in the UK and was cribbed from a design used on the New York Subway and seen in Coney Island overhaul works. The feature can be seen in the photo in the post above. When was this Top Hat check rail installed ? In 1967 I was a signalman at Piccadilly Circus station and it had a scissors crossover and it had just plain check rails on the points. When a southbound train was reversed via the northbound platform the driver had to stop in the tunnel beyond the platform, the points put back to normal, a signal then was cleared and the train moved up to the northbound starting signal. |
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Tom
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Post by Tom on May 30, 2021 10:28:39 GMT
It was installed over the August Bank Holiday weekend in 2009 - the work included the conversion of 7A points from four-foot to clamplock operation (introducing the first Mark 2 clamplocks onto LU). It's a most unusual arrangement: in addition to the house-top, supplementary detection is fitted despite the switches being very short and not normally requiring supplementary detection. The track gauge also progressively widens on the approach to the points beyond the normal 1432-1435mm range, from memory it's around 1450 at the switch rail toes. Modelling showed that there was a significant risk of derailment even at the nominal speed limit of the crossover. The solution was to provide a continuous check rail though the points. This is almost unique in the UK and was cribbed from a design used on the New York Subway and seen in Coney Island overhaul works. The feature can be seen in the photo in the post above. I had a feeling you'd know!  The arrangement is very common all over New York and North America in general - I've seen similar in Toronto too. It seems to be done as standard there. I've seen photos and videos from the prefabrication of the layout and the points were operated on the pre-fab by a Union Switch and Signal point motor imported from New York. |
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Post by superteacher on May 30, 2021 10:44:24 GMT
I think that NB to SB reversing (via main line shunt) is still permitted. A couple of years ago, they had contingency plans to do that when it looked like engineering works would overrun. In the event, they finished just in time.
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Post by Dstock7080 on May 30, 2021 11:54:27 GMT
I think that NB to SB reversing (via main line shunt) is still permitted. A couple of years ago, they had contingency plans to do that when it looked like engineering works would overrun. In the event, they finished just in time. Still possible using signal BP4, just north of the station. |
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Post by hugbilly on Jun 25, 2022 8:24:30 GMT
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towerman
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Post by towerman on Jun 25, 2022 10:52:02 GMT
It’s certainly been used during service suspensions and planned engineering works. Beyond that, there are no scheduled reversers there. Didn’t something derail on it a few years ago? As far as I can recall, not since the 1990s. There were two 72 stock derailments around that time, both incidents resulting in cars being written off. One of them was during the long-term closure south of Piccadilly Circus for tunnel works. I think that was the most recent. The speed controlled signals seem to have done the trick, as I think we can infer both of the 72 stock incidents were due to excess speed. The tunnel cleaning train incident wasn’t though, that was an issue with the train itself which became an issue on the awkward angles of the crossover. I seem to remember reversing NB to SB was banned, and may still be. Again all down to the specific issues with the crossover. 3257 was written off,3357 was reversed & renumbered 3299 with a spare UCNDM at the other end. |
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Post by spsmiler on Jun 27, 2022 23:29:22 GMT
If that worked (without derailments) in that format then why was it changed to a 'less good' format? Money / cost? |
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metman
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Post by metman on Jun 28, 2022 17:26:20 GMT
The removed part of the scissors looks like it was intended for 6 car operation with the current 7 car trains passing the blades to fit the platform.
Operationally it was probably quite a challenge to reverse a train onto the running line but that’s pure guesswork on my part.
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Post by scheduler on Jun 29, 2022 19:30:14 GMT
The current Working Timetable 47 for the Bakerloo Line has a Train Operator Training Path for the crossover. See page 5.
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Post by dpr on Jul 9, 2022 1:31:50 GMT
There's also a timetabled reverser early on a Saturday morning which runs empty southbound, reverses at Piccadilly, then enters service at OXO northbound. (Page 34)
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Post by joshua on Feb 4, 2023 0:56:10 GMT
Will that crossover stay if the Bakerloo ever get's ATO?
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