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Post by joeltancl on Jun 5, 2022 9:52:19 GMT
Dear Members
Elsewhere on this Forum it is written that some cars of the Victoria line's former 1967 Stock fleet were actually conversions from 1972 Mk1 Stock (formerly of the Northern line). Some driving motor-trailer (DM-T) pairs taken from 4-car and 3-car units of 1972Mk1 Stock were involved. However, I have not been able to find material showing what work was done to convert them, beyond mention of some electrical-related work.
My questions are:
1. Does anyone in this Forum have more details of what work was done to convert the '72Mk1 cars to be compatible with the original 1967 Stock fleet?
2. How similar, or different, was this conversion work to the work that made the '72Mk1 cars working on the Bakerloo line in the present day compatible with their '72Mk2 counterparts?
If this has already been answered elsewhere on the Forum please feel free to point me to the relevant thread. To the Moderators, please also feel free to move this thread to the right board if you think it fits better in another board. I left it here because I am not sure if it would fit better in here or the Rolling Stock discussion board, since the questions partly relate to a fleet that is now withdrawn.
Thank you!
Joel
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Post by Chris L on Jun 5, 2022 10:52:23 GMT
The units transferred to the Victoria line were only used in the middle of trains so they did not need to be fitted with the automatic driving units. This shows the work done on the 1972 stock to make them compatible with each other. www.trainweb.org/tubeprune/72%20tube%20stock.htm |
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Post by joeltancl on Jun 5, 2022 11:47:56 GMT
The units transferred to the Victoria line were only used in the middle of trains so they did not need to be fitted with the automatic driving units. This shows the work done on the 1972 stock to make them compatible with each other. www.trainweb.org/tubeprune/72%20tube%20stock.htmChris L, thanks, that answers my second question. So it seems that the only thing needed for the "Mk1-Mk2 interworking" was some rewiring work. As for the Victoria line conversion, what was done? As no Automatic driving equipment was needed, was any rewiring or other work done to the "ex-'72Mk1" cars? Or could a '72Mk1 DM-T pair (inner end) be just coupled to a '67 T-DM pair (outer end) and it would be ready to run? Thanks again! |
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bigvern
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Post by bigvern on Jun 5, 2022 22:16:21 GMT
From memory from my days at NPK.
The 1972 MK1 conversions for the Victoria line a mechanical governor was added to the trailer car, the tripcock was removed from the DM car and tripcock isolating cock removed.
Modifications to the Rheo 1 and hold braking circuits so that they worked in ATO, modification to the deadman circuit to enable trains not to overspend in depot by operation of the deadman above 10mph and a speed warning at 8mph.
Guards panels and door controls removed
Compressors these were retained and units selected had the same compressors as 67ts
On the ex special trailer car the pressure switch and braking system was made as a normal trailer car.
Traction modifications to the weak field by changing resistances.
Other wiring works to enable traction circuits to work, two units which had special trailers were fitted with special double headed intercar jumpers rather than a hard wired jumper to the case.
The semi permanent coupler was rebushed to match the coupling pins between 67 and 72s as 67s had a larger pin.
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Post by joeltancl on Jun 6, 2022 5:31:11 GMT
From memory from my days at NPK. The 1972 MK1 conversions for the Victoria line a mechanical governor was added to the trailer car, the tripcock was removed from the DM car and tripcock isolating cock removed. Modifications to the Rheo 1 and hold braking circuits so that they worked in ATO, modification to the deadman circuit to enable trains not to overspend in depot by operation of the deadman above 10mph and a speed warning at 8mph. Guards panels and door controls removed Compressors these were retained and units selected had the same compressors as 67ts On the ex special trailer car the pressure switch and braking system was made as a normal trailer car. Traction modifications to the weak field by changing resistances. Other wiring works to enable traction circuits to work, two units which had special trailers were fitted with special double headed intercar jumpers rather than a hard wired jumper to the case. The semi permanent coupler was rebushed to match the coupling pins between 67 and 72s as 67s had a larger pin. Thank you bigvern! So it was not that simple after all... That could explain a lot of other things now! (Apologies for drifting slightly off topic, but...) could the difference between the "current" circuitry scheme and that of cars in the present-day Bakerloo fleet be one of the reasons why they did not send the converted '72Mk1 cars back to the Bakerloo, even if they were sent without the '67 Stock cars they had worked with? (The plans were discussed in another thread.) I can now imagine that if the plans to send them to the Bakerloo after their time on the Victoria went ahead, money would have to be spent undoing some of these changes at least and then doing some more rewiring work to make them compatible with the Mk2s. |
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metman
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Post by metman on Jun 12, 2022 8:27:57 GMT
A few 1972mk1 units were specially retained at Eastleigh until a few years ago to allow insertion into the Bakerloo Fleet so it was clearly considered worth the effort. These have now been scrapped.
Interestingly the spare uncoupling non driving motors (4) made spare from the 3 car units converted were used for livery trials in the 1990s.
Of course several Mark1 trains were moved to the Bakerloo later in life too but that’s another story….
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Post by joeltancl on Jun 13, 2022 4:25:29 GMT
A few 1972mk1 units were specially retained at Eastleigh until a few years ago to allow insertion into the Bakerloo Fleet so it was clearly considered worth the effort. These have now been scrapped. Interestingly the spare uncoupling non driving motors (4) made spare from the 3 car units converted were used for livery trials in the 1990s. Of course several Mark1 trains were moved to the Bakerloo later in life too but that’s another story…. Thanks metman. I am aware of the other Bakerloo Mk1s which have never served on the Vic (Units 3264, 3265, 3267, 3564-3567 and half of 3266), those were discussed elsewhere too... It seems that the idea of adding the ex-Victoria 72Mk1s was considered, but then dropped for some reason... maybe the further modification work required was one of the reasons? Also, I seem to recall seeing some pictures and videos that suggest that the 67's had pressure gauges in lb/in2 while at least part of the '72 fleet had pressure gauges that read in bar. Were the pressures used by the 67's and 72's equivalent to each other, if one were to convert between lb/in2 and bar? If they were not identical at first, it could be that some related work was also part of the Vic line modification package for the ex-Northern 72Mk1s... |
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towerman
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Post by towerman on Jun 13, 2022 9:25:07 GMT
I thought 73TS was the first stock to have air pressure gauges in bars.
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Post by joeltancl on Jun 13, 2022 10:40:11 GMT
I thought 73TS was the first stock to have air pressure gauges in bars. You may refer to this pic from Tubeprune's site here: www.trainweb.org/tubeprune/72%20TS%20Cabs.htm (the first one) I think it is likely that the pressure gauge is not reading in lb/in2 because the markings don't go up to the high tens or the low hundreds... I remember reading elsewhere that the usual pressure for the train line was something like 60's or 70's lb/in2? See districtdavesforum.co.uk/thread/1660/train-main-line-airAnyway the unit at the bottom of the gauge doesn't look like psi or lb/in2... |
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Post by Dstock7080 on Jun 13, 2022 10:50:36 GMT
Normally 65 lb/in2 train line; 85 lb/in2 main line. That ‘72 gauge is in bar. |
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Post by joeltancl on Jun 13, 2022 11:00:32 GMT
Normally 65 lb/in2 train line; 85 lb/in2 main line. That ‘72 gauge is in bar. Thank you for the clarification re Main and Train line pressure in lb/in2. Hmm... So that was why I was wondering if the 67s and the 72s used same pressures (if that were the case then it would just be a matter of converting between units). If not, then I think it can be fairly assumed that some conversions must have been done one way or the other... Thank you to all! I think my questions have been more or less answered, and I learnt a lot of interesting things about the history of the '72s and their conversions! In sum it appears that there were various issues at play that caused the proposal to add the ex-Vic 72Mk1s to the Bakerloo's fleet to be canned, and it was not as simple as just coupling those cars to a Bakerloo unit... correct me if I am wrong... |
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Post by Dstock7080 on Jun 13, 2022 11:23:31 GMT
Oddly both versions of C Stock, 1969 and 1977 both used lb/in2 gauges!
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Post by joeltancl on Jun 13, 2022 13:27:49 GMT
Oddly both versions of C Stock, 1969 and 1977 both used lb/in2 gauges! Wow, then that makes the difference in pressure gauge type between 67 and 72 Stock all the more interesting... hopefully we can hear more from those who know better... |
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bigvern
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Post by bigvern on Jun 13, 2022 16:24:58 GMT
When the 72 Mk1s were used on the Victoria Line the choke on the triple valve was also changed to increase the brake rate, as an 8 car train is heavier.
The direct LB perSq Inch and Bar were direct conversions the pressures were the same between the stocks.
Some other brake valves were recalibrated on the 72s to make compatable to the 67s.
The 67s also had doors with bottom rollers and tracks, with the 72 Mk2s having top hung doors with top tracks, all the 72Mk1s on the Bakerloo Line have had their doors replaced with brand new new top hung doors with removal of the bottom door track.
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Post by jimbo on Jun 13, 2022 20:38:23 GMT
Oddly both versions of C Stock, 1969 and 1977 both used lb/in2 gauges! Wow, then that makes the difference in pressure gauge type between 67 and 72 Stock all the more interesting... hopefully we can hear more from those who know better... Around the time the Nation was to change to metric measurements. Then a change of plan, and I think some new gauges had sticker over the original to revert to convention, or simply show high or low areas. With start of decimal coinage there had been enthusiasm to go the whole hog! Soon faded. Motorways were even laid out to permit change to driving on right as Sweden had changed in 1967. |
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Post by joeltancl on Jun 14, 2022 1:55:01 GMT
The direct LB perSq Inch and Bar were direct conversions the pressures were the same between the stocks. Some other brake valves were recalibrated on the 72s to make compatable to the 67s. The 67s also had doors with bottom rollers and tracks, with the 72 Mk2s having top hung doors with top tracks, all the 72Mk1s on the Bakerloo Line have had their doors replaced with brand new new top hung doors with removal of the bottom door track. Thanks again! So while the pressures were the same, even the 72Mk1 "siblings" started to take different paths on the Victoria and Bakerloo... Wow, then that makes the difference in pressure gauge type between 67 and 72 Stock all the more interesting... hopefully we can hear more from those who know better... Around the time the Nation was to change to metric measurements. Then a change of plan, and I think some new gauges had sticker over the original to revert to convention, or simply show high or low areas. With start of decimal coinage there had been enthusiasm to go the whole hog! Soon faded. Motorways were even laid out to permit change to driving on right as Sweden had changed in 1967. Interesting how things were (and are) in the UK (and the US, for that matter)... (I am from Singapore) And interesting that the 56/59/62 Stock was the last crew-operated tube stock to be entirely using imperial units for air pressure... But, for the intents and purposes of my thread, I have obtained the information I wanted. Thank you, again, to all! It's always a joy to learn about quirks about LU, its practices, rolling stock and infrastructure... |
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Post by seaeagle on Jun 14, 2022 21:57:47 GMT
Just as an add on to this thread, there was a rule that two 72 stock's on the Vic couldn't be coupled together when in service as Vic T/Op's weren't trained on them in the event of a train having to be uncoupled and driven from the middle cabs. You can imagine the farce when I discovered an eight car train with two 72 stocks in the middle at Brixton and refused to take it many years ago lol
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Post by joeltancl on Jun 15, 2022 2:29:55 GMT
Just as an add on to this thread, there was a rule that two 72 stock's on the Vic couldn't be coupled together when in service as Vic T/Op's weren't trained on them in the event of a train having to be uncoupled and driven from the middle cabs. You can imagine the farce when I discovered an eight car train with two 72 stocks in the middle at Brixton and refused to take it many years ago lol Lol what happened in the end? Did somebody else take it or it was never taken by anyone in the end? Just as a final add-on from me, further to what has already been discussed upthread I can also imagine some crews on the Northern in days of yore having issues when changing between the different systems of units for air pressure used on 38/56/59/62 (lb/in2) and 72 Stock (bar), even though they were supposed to be trained on all those types back in those days, but I think that would be best discussed in some other thread on this board sometime in the future... |
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