mrfs42
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Post by mrfs42 on Dec 24, 2007 12:31:09 GMT
Ancient Timetable question time: perusing a Coronation 1953 TTN: mention is made several times of different types of train:
7U = UNDM with shunting control on the 3-car portion
7B = 7 car block train
All others will be standard stock 7-car uncoupling trains (with 3-car portion fitted with additional compressor)
For 6/6/53 the stock composition makes reference to certain trains running as 'A' instead of 'U' stock, 'B' instead of 'A' stock and 'U' instead of 'A' stock. The max. number of trains shews 47x7, 11x7B, 26x7U.
Am I right in thinking that 'block' trains wouldn't uncouple and are therefore 'B' stock; 'U' stock is clearly the uncoupling trains - these would both be '38 stock?
Is the 'A' stock the 'standard stock'? Which sort of standard stock could this be: pre-38 or '38 stock that hasn't been meddled with?
The Timetable notice does not cover the Northern City line - that's in another one - which was still 'Standard stock'. I thought by 1953 all of the Northern services were handled by '38 stock, any thoughts?
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metman
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Post by metman on Dec 24, 2007 17:15:30 GMT
As far as I know, the Northern (bar the Highbury branch) was run purely by 38ts. I thought all trains were formed thus
DM-NDM-T-DM+DM-T-DM or DM-NDM-T-DM+UNDM-T-DM from 1949.
But the 9 car experiment was planned for the 38ts so the formations were ordered and supposed to run in DM + NDM + SNDM + T + NDM + T + SNDM + NDM + DM. This didn't happen so formations were reorganised in the 1950s and perhaps this is why the difference in stock letters.
I guess B38ts stock would have been DM-NDM-T-SNDM-SNDM-T-DM
with the U38ts DM-NDM-T-DM+DM/UNDM-T-DM
I think SNDM were non-driving motors without compressors?
Maybe tubeprune can help?
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mrfs42
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Post by mrfs42 on Dec 24, 2007 20:55:22 GMT
As far as I know, the Northern (bar the Highbury branch) was run purely by 38ts. So do I - I think the 'A' stock definition here means '38 stock that is 'as built', without any further modifications. I thought all trains were formed thus DM-NDM-T-DM+DM-T-DM or DM-NDM-T-DM+UNDM-T-DM from 1949. But the 9 car experiment was planned for the 38ts so the formations were ordered and supposed to run in DM + NDM + SNDM + T + NDM + T + SNDM + NDM + DM. This didn't happen so formations were reorganised in the 1950s and perhaps this is why the difference in stock letters. I guess B38ts stock would have been DM-NDM-T-SNDM-SNDM-T-DM with the U38ts DM-NDM-T-DM+DM/UNDM-T-DM If this helps in the thought processes: the maximum amount of stock allocated for service on 1/6, 3/6 - 5/6 (Mon, Wed - Fri of Coronation Week) was 100 trains, all of 7 cars with 55 just shewn as '7', 15 shewn as '7B' and 30 shewn as '7U'. By 1956 - the nearest Northern full WTT I've got to this - all trains are shewn as either '7' (55 trains) and '7U' (45 trains), with (un)coupling happening at Edgware, High Barnet and Morden. Here you've got units divided into 'N' and 'S' (presumably North and South - going on the District's Eastern and Western portions). However, there is only ever 3S, but there are both 4N and 4N(U). Maybe tubeprune can help? Oh yes - seems to be his sort of stuff.  |
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Post by tubeprune on Dec 25, 2007 9:36:04 GMT
[Oh yes - seems to be his sort of stuff. It is and I will try to find a simple way of explaining it. It occupies a whole chapter 4 of "The 1938 Tube Stock" by Piers Connor. I will get back to you. One thing I do remember is that uncoupling units (U7) could have an UNDM or a DM. But the arrangements did change over the years between 1939 and 1953. I do not recall the "A" train definition but I will look for it. |
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Post by tubeprune on Dec 27, 2007 10:18:40 GMT
Found it. The A train is one which can be uncoupled in service with the 3-car unit run as a train if required. These 3-car units had two compressors under the trailer. There was so much trouble with the 38TS compressors that it was decreed that no train should run without at least two operating compressors.
The B train is a block train which cannot be uncoupled. The U train is one with an UNDM. Eventually late in 1953 all B trains were converted to U trains.
The SNDM was originally intended for 9-car trains but was used in 7-car block trains until the conversion to U trains was completed. The SNDM had no compressor and was originally provided with guards controls at one end and a ward coupler at the other end.
I hope this sorts it out for everyone.
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mrfs42
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Post by mrfs42 on Dec 27, 2007 11:27:08 GMT
Most kind, thank-you TP. ;D
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Post by tubeprune on Dec 28, 2007 16:02:40 GMT
You are most welcome.
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metman
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Post by metman on Dec 28, 2007 17:13:32 GMT
I am actually quite suprised how many Northern Line trains there were with UNDM in. I thought that most of the trains had 2 middle cabs in. It must have been the Bakerloo trains that mostly had this. I believe the Bakerloo stock was delivered in 6 car trains DM-T-DM+DM-T-DM and then had a 1927 stock trailer added to make them 7 car trains!
When did the UNDM start to get withdrawn? I read (probably on Tubeprune's site) that parts of the UNDM were used in the 72ts UNDM.
Finally, I wonder why the 1959 stock was delivered as DM-NDM-T-DM+DM-T-DM rather than DM-NDM-T-DM+UNDM-T-DM. I can understand the 62ts having to deal with the Hainault loop but the picc was pre-Heathrow! It appears that UNDMs were becoming popular at the time. Did the 59ts uncouple in service?
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Post by tubeprune on Dec 29, 2007 7:37:37 GMT
I am actually quite suprised how many Northern Line trains there were with UNDM in. I thought that most of the trains had 2 middle cabs in. There were 46 U trains on the Northern out of 115 allocated under the 1949 uncoupling programme. The Bakerloo had 27 U trains (IIRC) and the Picc had 15. There were 58 trains with 1927 trailers and many of them started on the Northern. The Bakerloo was always intended to have 7-car trains. The 6-car formation on both lines during the war was due to restrictions on power supply and spare parts. Correct. They used the shunting control panels. The 59s were ordered when uncoupling was still operated. The 56TS used to unpouple. There was also a desire for standardisation - long since lost. |
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metman
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Post by metman on Dec 29, 2007 13:19:50 GMT
Cheers!
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mrfs42
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Post by mrfs42 on Jan 8, 2008 7:52:43 GMT
[Oh yes - seems to be his sort of stuff. It is and I will try to find a simple way of explaining it. It occupies a whole chapter 4 of "The 1938 Tube Stock" by Piers Connor. I will get back to you. It does doesn't it! I've managed to hunt down a copy of that very book. Very readable - even for such a specialist subject. |
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