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Post by darwins on Aug 25, 2019 5:58:48 GMT
Having searched the boards there seems to be a fair amount of discussion of speeds for modern stock, but not much information for older vehicles. I would be interested to know the designed maximum speeds of early electric stock - or estimates based on things like motor speeds, power and gear ratios for those who like calculations. All I have been able to gather so far: The CLR and CLSR locomotives had a maximum speed of 25 mph. Was this also the maximum speed of tube trains in the early 20th century? (Central London and Gate stock) Was the tube stock designed to go further on the surface built to go faster? (Ealing and Watford stock - the latter having to fit in with LNWR trains having a 45 mph limit - although I gather the original Watford stock was not up to the job.) What about Standard Stock and 1938 stock? As to surface stock I have read that F stock built to run up to 45 mph in 1920 did not fit into paths with the older slower stock - how fast could the older stock travel? Would about the newer motor cars that become Q stock? What about the District locomotives? Is it likely that fitting F stock motors in them increased their speed over the original? The Metropolitan (1921) locomotives apparently had a maximum of 65 mph. What about earlier locomotives and MU stock on the Met? What about O and P stock - were there different speeds designed for the different services?
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roythebus
Pleased to say the restoration of BEA coach MLL738 is as complete as it can be, now restoring MLL721
Posts: 1,275
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Post by roythebus on Aug 27, 2019 12:42:35 GMT
The maximum speed of any electric stock is limited by the balancing speed of the traction motors. That is called the back electro-motive force or EMF. thihis reduces the magnetics is the psee dat which the magnetic forces of motors equalise. The way round that is to introduce field weakening; this reduces the magnetism on the field winding which will enable the motor to turn faster. Whoever has the answer to that can then work out from the gearing and wheel diameter what the maximum speed could be.
As older stock wasn't generally fitted with speedometers it was not possible for the motorman to know haw fast the train was going. It was estimated on experience. Generally it was assumed that with the controller in series the maximum speed woul be 25 mp, is parallel about 40-45. with weak field that could get another 10mph or so.
From my experience of Q/CP/CO stock on the District, Q stock was perceived to be faster than the others in the east end; R stock would accelerate quicker as every axle was motored, but then a CP composed of 4x2 car sets would be even quicker.
A stock was more than capable of speeds in excess of 60 mph; C69 wouldn't do much more than 45 on an empty run from Neasden to Baker Street and that's down hill all the way; the 1938 tube stock tour of the Met in early 1973 achieved just over 60 from Chorleywood to Ricky. I was in the leading cab at the time.
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DWS
every second count's
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Post by DWS on Aug 28, 2019 5:15:39 GMT
The maximum speed of any electric stock is limited by the balancing speed of the traction motors. That is called the back electro-motive force or EMF. thihis reduces the magnetics is the psee dat which the magnetic forces of motors equalise. The way round that is to introduce field weakening; this reduces the magnetism on the field winding which will enable the motor to turn faster. Whoever has the answer to that can then work out from the gearing and wheel diameter what the maximum speed could be. As older stock wasn't generally fitted with speedometers it was not possible for the motorman to know haw fast the train was going. It was estimated on experience. Generally it was assumed that with the controller in series the maximum speed woul be 25 mp, is parallel about 40-45. with weak field that could get another 10mph or so. From my experience of Q/CP/CO stock on the District, Q stock was perceived to be faster than the others in the east end; R stock would accelerate quicker as every axle was motored, but then a CP composed of 4x2 car sets would be even quicker. A stock was more than capable of speeds in excess of 60 mph; C69 wouldn't do much more than 45 on an empty run from Neasden to Baker Street and that's down hill all the way; the 1938 tube stock tour of the Met in early 1973 achieved just over 60 from Chorleywood to Ricky. I was in the leading cab at the time. Did the 1938 tube stock 4 car unit used in the tour that you traveled in the leading cab in 1973 have a speedometer ? |
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roythebus
Pleased to say the restoration of BEA coach MLL738 is as complete as it can be, now restoring MLL721
Posts: 1,275
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Post by roythebus on Aug 30, 2019 21:48:04 GMT
Yes, it was a 7 car train, not 4, and it had one of the standard stock trailers in it as well. I heard several people on the train were timing it, and it got to "well over 60". There was also a D.I. in the cab and luckily he was looking out of the other window.  |
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Post by Chris L on Aug 31, 2019 8:22:45 GMT
The 4 car 1938 stock trains which ran on the East London Line without speedometers reportedly reached decent speeds between stations.
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Post by Dstock7080 on Aug 31, 2019 9:55:54 GMT
7-car refreshed ‘38s on the Northern Line 1986-88 certainly didn’t have speedometers
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Post by superteacher on Aug 31, 2019 19:28:27 GMT
Pretty sure none of them ever had speedos fitted as standard.
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Post by movingmillion on Sept 1, 2019 0:17:28 GMT
I am pretty sure I remember my dad saying a while ago that when he was a driver on the Met Line in the 80s that he probably drove the A60 at about 80mph or so a couple times (presumably on empty movements); though he didn't know for certain as the speedometer never went that high.
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Post by Dstock7080 on Sept 1, 2019 6:22:16 GMT
I am pretty sure I remember my dad saying a while ago that when he was a driver on the Met Line in the 80s that he probably drove the A60 at about 80mph or so a couple times (presumably on empty movements); though he didn't know for certain as the speedometer never went that high. A Stock speedometers were only marked up to 70, so anything above was guesswork! They could be very inaccurate too, fluctuating greatly while maintaining a steady speed. Heading southbound from Chorleywood could certainly get past the 70. |
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Post by spsmiler on Sept 2, 2019 18:42:55 GMT
Ah, memories of a downhill non-stop high-speed A stock run from Amersham to Rickmansworth on a Boxing day in the 1980s. Quite literally we flew... I tried to film some station passes using my super 8 film camera but the ride was too unsteady.
Its a shame that the actual speed will likely never be known.
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Post by darwins on Oct 15, 2019 13:45:03 GMT
Many thanks for your replies so far.
Any thoughts on anything even older?
I read that the District (1920) F stock could reach 45 mph, but that in the WTT it was restricted to 35 mph - so presume that would have been the max speed of the older District Stock.
Any thoughts on older Metropolitan stock (pre 1938) or older tube stock Standard Stock or before?
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Post by spsmiler on Oct 15, 2019 19:17:09 GMT
I think its the F stock where the trains had to have some motors removed because the trains were deemed to be 'too powerful' with them.
Hopefully someone else here will know more than me on this topic.
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Post by underover on Oct 16, 2019 18:42:20 GMT
I am aware of stock which unofficially has hit just shy of 70 before the driver has thought to slow down a bit.
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metman
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Post by metman on Oct 16, 2019 20:21:28 GMT
I think its the F stock where the trains had to have some motors removed because the trains were deemed to be 'too powerful' with them. Hopefully someone else here will know more than me on this topic. The original F stock formation was M-T-T-T-M+CT-T-M with all three motor cars being double equipped. When the district locos were re-equipped the middle motor car was reduced to a single equipment - ie with two motors removed from the trailing bogie. In 1938 the control trailers were converted to single equipped motor cars with the motors previously removed from the middle motor cars so the trains reverted to their original 12 motors. |
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Post by littlejohn on Oct 17, 2019 12:12:37 GMT
I think its the F stock where the trains had to have some motors removed because the trains were deemed to be 'too powerful' with them. Hopefully someone else here will know more than me on this topic. The original F stock formation was M-T-T-T-M+CT-T-M with all three motor cars being double equipped. When the district locos were re-equipped the middle motor car was reduced to a single equipment - ie with two motors removed from the trailing bogie. In 1938 the control trailers were converted to single equipped motor cars with the motors previously removed from the middle motor cars so the trains reverted to their original 12 motors. I have been re-reading the F Stock chapter in Steam to Silver. It says that F Stock could accelerate at 1.5 mph/second, which was superior to anything else on the District. The trains were intended to be operated at 45mph but were found to be capable of achieving more than this. They were thus considered over-powered and wasteful of electricity and so 14 (with another later) were converted to single equipment. As an aside, the 14 x removed equipment was fitted in twos to the 7 electric locomotives hauling the Southend trains in order to improve their performance. |
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Post by d7666 on Oct 18, 2019 13:43:55 GMT
The maximum speed of any electric stock is limited by the balancing speed of the traction motors. That is called the back electro-motive force or EMF. thihis reduces the magnetics is the psee dat which the magnetic forces of motors equalise. The way round that is to introduce field weakening; this reduces the magnetism on the field winding which will enable the motor to turn faster. Whoever has the answer to that can then work out from the gearing and wheel diameter what the maximum speed could be. As older stock wasn't generally fitted with speedometers it was not possible for the motorman to know haw fast the train was going. It was estimated on experience. Generally it was assumed that with the controller in series the maximum speed woul be 25 mp, is parallel about 40-45. with weak field that could get another 10mph or so. From my experience of Q/CP/CO stock on the District, Q stock was perceived to be faster than the others in the east end; R stock would accelerate quicker as every axle was motored, but then a CP composed of 4x2 car sets would be even quicker. A stock was more than capable of speeds in excess of 60 mph; C69 wouldn't do much more than 45 on an empty run from Neasden to Baker Street and that's down hill all the way; the 1938 tube stock tour of the Met in early 1973 achieved just over 60 from Chorleywood to Ricky. I was in the leading cab at the time. Only just looked again at this thread. I had thought in my archives boxes I had some motor and performance data on O R A C D stock, but I can't find it . Hope it's not gone missing as to my knowledge it's not in the public domain and merits a wider audience. Anyway. In the quote above it is written every R stock axle powered. That's thrown me a bit. I thought R was every bogie powered, but one motor axle per bogie I.e. in other parlance I thought R were A1 or 1A bogies throughout not Bo bogies. Amazingly I can't find an authoritative source on the web for this, all say all cars motored, but not much more, and none of my books go into this aspect in depth. |
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metman
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Post by metman on Oct 19, 2019 16:05:20 GMT
You are correct. The R stock had every bogie powered with one motor fitted per bogie in an asymmetrical manner just like the O/P/Q38 surface stocks and 1935/38/49 tube stocks. The 1956/59/62 stocks followed suit.
Two motors per bogie was not reintroduced until the 1960 cravens tube stock although there were trials on the 1938 and R stock.
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Post by d7666 on Oct 19, 2019 16:32:23 GMT
You are correct. The R stock had every bogie powered with one motor fitted per bogie in an asymmetrical manner just like the O/P/Q38 surface stocks and 1935/38/49 tube stocks. The 1956/59/62 stocks followed suit. Two motors per bogie was not reintroduced until the 1960 cravens tube stock although there were trials on the 1938 and R stock. THanks! Back to performance data, I had another session digging through boxes. Not found. I know it is paper not electIiironic. Should it surface at some point, assuming I remember, I'll post it. |
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Post by darwins on Oct 24, 2019 7:24:30 GMT
Thanks. Hope you do find it. Sounds like one of those odd items that many of us collect and perhaps ought to be shared.
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Post by d7666 on Mar 9, 2020 16:37:53 GMT
You are correct. The R stock had every bogie powered with one motor fitted per bogie in an asymmetrical manner just like the O/P/Q38 surface stocks and 1935/38/49 tube stocks. The 1956/59/62 stocks followed suit. Two motors per bogie was not reintroduced until the 1960 cravens tube stock although there were trials on the 1938 and R stock. THanks! Back to performance data, I had another session digging through boxes. Not found. I know it is paper not electronic. Should it surface at some point, assuming I remember, I'll post it. I have located the data for D C and A stock. As usual, I wasn't looking for this, but something else. There are 6 PDFs, not sure how I can attach them to a post (being PDFs). I suppose one solution is scan them to images and attach jpg files, but again not sure if that works here. Not found the O P R stock data yet. |
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Post by John Tuthill on Mar 9, 2020 20:10:23 GMT
THanks! Back to performance data, I had another session digging through boxes. Not found. I know it is paper not electronic. Should it surface at some point, assuming I remember, I'll post it. I have located the data for D C and A stock. As usual, I wasn't looking for this, but something else. There are 6 PDFs, not sure how I can attach them to a post (being PDFs). I suppose one solution is scan them to images and attach jpg files, but again not sure if that works here. Not found the O P R stock data yet. Have you looked at 'From Steam to Silver' (Capital Transport)? |
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Post by d7666 on Mar 9, 2020 20:51:48 GMT
I have located the data for D C and A stock. As usual, I wasn't looking for this, but something else. There are 6 PDFs, not sure how I can attach them to a post (being PDFs). I suppose one solution is scan them to images and attach jpg files, but again not sure if that works here. Not found the O P R stock data yet. Have you looked at 'From Steam to Silver' (Capital Transport)? Err no, why would I, not sure I understand this comment, the discussion is about me getting the data I have into the public domain, not about me wanting data already out there. |
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Post by John Tuthill on Mar 9, 2020 21:15:35 GMT
Have you looked at 'From Steam to Silver' (Capital Transport)? Err no, why would I, not sure I understand this comment, the discussion is about me getting the data I have into the public domain, not about me wanting data already out there. Sorry, just thought it would give you an option. |
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Post by Chris W on Mar 9, 2020 21:43:44 GMT
I have located the data for D C and A stock. As usual, I wasn't looking for this, but something else. There are 6 PDFs, not sure how I can attach them to a post (being PDFs). I suppose one solution is scan them to images and attach jpg files, but again not sure if that works here. Not found the O P R stock data yet. Does your scanner, allow you to specify the file type? My HP printer/scanner allows me to scan, converting paperwork to either .PDF or .JPG files I'm happy to host material on my Flickr site if you don't have anywhere/an account yourself. If necessary email the .PDF's to me and I'll convert... PM me if you would like me to assist  |
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Post by spsmiler on Mar 10, 2020 0:03:55 GMT
Maybe tweeting with the pdf files attached will be of benefit?
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Post by fish7373 on Mar 10, 2020 1:07:57 GMT
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Post by countryman on Mar 10, 2020 8:29:37 GMT
Copied from the pdf section on Bakerloo 1972 stock.
'Formation per unit: Four cars, formed DM – T – T – DM*, and three cars formed UNDM – T - DM
Formation per train: Eight cars, formed DM – T – T – DM + UNDM – T – DM*
8 one train is formed of DM – T – T – UNDM – UNDM – T- DM'
Unfortunately there is an error in that they seem to think these ran as 8 car trains.
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metman
Global Moderator
5056 05/12/1961-23/04/2012 RIP
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Post by metman on Mar 10, 2020 12:24:54 GMT
Yes the 1972 stock were designed and operated to run in 7 car formations as restricted by the platform lengths on the Northern and Jubilee/Bakerloo. Some 1972 stock did run in 8 car formations but only when incorporated into the 1967 stock on the Victoria line so I don’t really count that!
I believe the reference is to the one train which has a UNDM (uncoupling non driving motor) in place of a normal driving motor (after collision damage some years back now), perhaps this is where the confusion came from - it still runs as a 7 car train of course.
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Post by d7666 on Mar 10, 2020 14:00:57 GMT
I have located the data for D C and A stock. As usual, I wasn't looking for this, but something else. There are 6 PDFs, not sure how I can attach them to a post (being PDFs). I suppose one solution is scan them to images and attach jpg files, but again not sure if that works here. Not found the O P R stock data yet. Does your scanner, allow you to specify the file type? My HP printer/scanner allows me to scan, converting paperwork to either .PDF or .JPG files I'm happy to host material on my Flickr site if you don't have anywhere/an account yourself. If necessary email the .PDF's to me and I'll convert... PM me if you would like me to assist Hi, thanks, I thought of all the above, and can do myself, have a flickr a/c, I was just wondering if/how you attach a file directly ,to a post right here, rather than putting it somewhere else and linking. |
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Chris M
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Post by Chris M on Mar 10, 2020 14:11:10 GMT
Hi, thanks, I thought of all the above, and can do myself, have a flickr a/c, I was just wondering if/how you attach a file directly ,to a post right here, rather than putting it somewhere else and linking. You can't. When you see images inline they are hosted elsewhere and displayed from there, everything else can only be linked. |
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