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Post by q8 on Oct 25, 2005 0:56:46 GMT
What's the procedure with the 'weak field flag switch' nowadays? In my time the rule on all lines except the 'Met' north of Finchley Road was that it was never to be used unless instructed.
On all lines except the District this was obeyed. On the DR only one stock (R) had them and with those they were always cut in as without that the stock was gutless and sluggish.
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Deleted
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Post by Deleted on Oct 25, 2005 2:40:52 GMT
Can't speak for other lines, although the 96 stock (Jubilee) doesn't have such a thing!
On the District we have the Weak Field flag and the Coasting Control flag. The Weak Field is only to be used east of Bow Road and west of Turnham Green/Putney Bridge.
A lot of the drivers, myself included at times, run everywhere with the coasting flag up as this allows the train to get up to about 45mph, whereas without it the motors cut out at 30.
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Colin
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Post by Colin on Oct 25, 2005 3:19:55 GMT
I used to be a good boy and only use the weak field where allowed - now, purely out of laziness, I have the coasting control up all the time.
Mind you this leads nicely to a question I have (maybe one for PeteUXB):
On the D's it's yellow/black for the weakfield and Green/white for the coasting control. Now when we pass Aldgate, I notice the A stock has a yellow/black flag up. Does that mean they're using the weakfield in the central area?
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Post by Deleted on Oct 25, 2005 9:55:20 GMT
What's the procedure with the 'weak field flag switch' nowadays? In my time the rule on all lines except the 'Met' north of Finchley Road was that it was never to be used unless instructed. Hang about. The 1938 TS had weak field, and they didn't run on the Met. LT was fairly extravagant in its equipment specifications, but it was unlikely to include this feature on 850 motor cars if it was not going to be used regularly. |
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Post by q8 on Oct 25, 2005 10:00:00 GMT
To answer Colin's question it does mean that the weak field is 'on' and that the driver has either forgotten to put it down at Finchley Road or is too lazy. However he should have noticed as the accelartion with an 'A' strock weak field in is only rate one which is NOT a good idea in the city
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Post by q8 on Oct 25, 2005 10:03:50 GMT
Hang about. The 1938 TS had weak field, and they didn't run on the Met. LT was fairly extravagant in its equipment specifications, but it was unlikely to include this feature on 850 motor cars if it was not going to be used regularly.
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ALL stock 1938 to 1962 except COP had a weak field flag. But the ONLY line where it use was authorised was the MET. Mind you us boys on the Bakerloo would whack it on leaving Baker Street for the long climb to Finchley Road. We'd also use it to race a Met from Wembley to Neasden
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Phil
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Post by Phil on Oct 25, 2005 10:45:04 GMT
Was it not authorised on the open-air sections of the Picc at both ends?
If not there were an AWFUL lot of motormen who ignored it when I were a lad....
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Phil
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Post by Phil on Oct 25, 2005 10:48:34 GMT
Mind you us boys on the Bakerloo would whack it on leaving Baker Street for the long climb to Finchley Road. We'd also use it to race a Met from Wembley to Neasden You've confuzzled me again Q8! Wasn't it the case that acceleration is REDUCED in WF? Why then would you want it IN on a long climb (or was the extra top speed the point?) |
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Post by q8 on Oct 25, 2005 10:52:41 GMT
Nah. The accelaration rate was only reduced on 'A' stock. On all other you got normal acceleration wether it was up or down. Hence on leaving Baker you got a good push to start and higher rate to climb the hill
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Post by trainopd78 on Oct 25, 2005 21:50:57 GMT
On D stocks, you feel the added power when you rasie the WF flag whilst in parallel. It's not that much, but it is noticable.
BTW we arent allowed both flags up at the same time on D's unless there is a confirmed motor defect and the line controller is aware.
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Deleted
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Post by Deleted on Oct 25, 2005 21:56:59 GMT
BTW we arent allowed both flags up at the same time on D's unless there is a confirmed motor defect and the line controller is aware. Yeah, spoilsports!  Anyone know WHY we can't use both together - is it just that they don't trust us to watch our speed? |
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solidbond
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Post by solidbond on Oct 25, 2005 22:23:02 GMT
BTW we arent allowed both flags up at the same time on D's unless there is a confirmed motor defect and the line controller is aware. Yeah, spoilsports! Anyone know WHY we can't use both together - is it just that they don't trust us to watch our speed? The problem was that the District didn't have a published line speed, and as a result, if both flags were raised, it could compromise the signal overlaps, due to the better acceleration, and higher top speed achievable. Now that there are maximum speeds on all parts of the District, there is no logical reason for the ban on both flags, but until the rules catch up, it still exists. (I couldn't possibly comment as to whether the rules may change in the future ;D) |
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Phil
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Post by Phil on Oct 25, 2005 22:26:00 GMT
On D stocks, you feel the added power when you rasie the WF flag whilst in parallel. Can you do it 'on the road' then? Isn't the switch still under the flag itself, and if so how is it reached whilst on the move? Or would that be saying? ;D ;D ;D ;D ;D ;D |
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solidbond
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Post by solidbond on Oct 25, 2005 22:28:46 GMT
Can you do it 'on the road' then? Isn't the switch still under the flag itself, and if so how is it reached whilst on the move? Or would that be saying? ;D ;D ;D ;D ;D ;D The flag is the switch, so lifting the flag, immediately activates the weak field ;D |
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Phil
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Post by Phil on Oct 25, 2005 22:33:24 GMT
Can you do it 'on the road' then? Isn't the switch still under the flag itself, and if so how is it reached whilst on the move? Or would that be saying? ;D ;D ;D ;D ;D ;D The flag is the switch, so lifting the flag, immediately activates the weak field ;D So how do you reach it if seated at the desk - it's on the other side of the cab! |
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Post by Deleted on Oct 25, 2005 22:50:04 GMT
Hang about. The 1938 TS had weak field, and they didn't run on the Met. LT was fairly extravagant in its equipment specifications, but it was unlikely to include this feature on 850 motor cars if it was not going to be used regularly. ----------------------------------------------------------------------- ALL stock 1938 to 1962 except COP had a weak field flag. But the ONLY line where it use was authorised was the MET. Mind you us boys on the Bakerloo would whack it on leaving Baker Street for the long climb to Finchley Road. We'd also use it to race a Met from Wembley to Neasden It seems extracordinary that LT would spend money, over so long a period, on a feature that drivers were not supposed to use. At p 61 of "The 1938 Tube Stock" there is a picture of 38 TS coming into Kilburn southbound, according to the caption in 1950, with the WF flag clearly raised. So it would seem that practice sometimes differed from theory. |
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Colin
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Post by Colin on Oct 26, 2005 3:59:24 GMT
To answer Colin's question it does mean that the weak field is 'on' and that the driver has either forgotten to put it down at Finchley Road or is too lazy. However he should have noticed as the accelartion with an 'A' strock weak field in is only rate one which is NOT a good idea in the city Now I don't think I quite follow you here  You say it's not a good idea in the city and that drivers have forgotten to put it down - but every train without exception has it up at Aldgate. I'm thinking that a flag raised on A stock has the opposite effect to a D stock - is that what you mean? So how do you reach it if seated at the desk - it's on the other side of the cab! Aha - it's only out of reach if you have short arms!! ;D |
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Post by q8 on Oct 26, 2005 5:39:50 GMT
Colin you misunderstand. If the WF flag is raised on an 'A' stock you can only get rate 1 acceleration and therefore a slower build up of speed but a higher speed when top notch is reached. They were designed like that.
The disadvantage of having the WF flag up in the city on 'A' stock is that as the acceleration rate is slower then it takes longer for a train to clear the platform and therefore longer for the home signals to clear. As 'C' stock has a high rate of accelration, when the 'big lad' is creeping out of the platform it will slow the 'C' down unecessarily and cause block back and bunching.
This frustrates the aim of having close headway signalling in town and the signal controller has extra work to correct this.
We had similar situation on the DR in the 60's with 3 different stocks to play with. A 'Q' would accelrate very slowly in leaving a platform and as a result had a gap in front of him. An 'R' would take off like a rocket and would consequently be up the rear of the preceding train and forever having to brake, accelerate, brake, accelerate all the time. This was hard work on drivers. The differering rates of acceleration led to bunching and usually 20 mins plus of lateness every peak hour. Quite often you were 40 mins late!!
So if ALL trains used the same rate of acceleration in town things would be smoothed out and run better. Therefore if 'A' stock drivers refrained from having the flag up in town they would have an easier life.
One other thing. Current consumption with the weak field switch in is very much higher so will not please the money men
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Post by q8 on Oct 26, 2005 5:50:04 GMT
It seems extracordinary that LT would spend money, over so long a period, on a feature that drivers were not supposed to use.
At p 61 of "The 1938 Tube Stock" there is a picture of 38 TS coming into Kilburn southbound, according to the caption in 1950, with the WF flag clearly raised. So it would seem that practice sometimes differed from theory.
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Yes practice did differ from theory but you were strictly FORBIDDEN to use the weak field by regular and repeated warnings in the traffic circular.A driver could (and sometimes was) put on a disciplinary board if caught using it unauthorised. If you had been caught using in on repeated occasions you got the sack.
As I said elsewhere the prohibtion was to save on current consumption (very much higher with the flag up) and also because the signalling did not take account of the higher speed you could attain with the WF operative. That could result in a rear end shunt in certain circumstances. So not a good idea. They did in the end remove the WF switch from some of the 38 stock after the second Tooting siding incident where the flag was found to be raised I beleive.
So if a driver is mindful of his own safety and that of his passengers he'll leave the WF down where it's not meant to be used. If something untoward happens he'll be on a manslaughter charge.
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Post by Deleted on Oct 26, 2005 5:53:17 GMT
To answer Colin's question it does mean that the weak field is 'on' and that the driver has either forgotten to put it down at Finchley Road or is too lazy. However he should have noticed as the accelartion with an 'A' strock weak field in is only rate one which is NOT a good idea in the city Now I don't think I quite follow you here You say it's not a good idea in the city and that drivers have forgotten to put it down - but every train without exception has it up at Aldgate. I'm thinking that a flag raised on A stock has the opposite effect to a D stock - is that what you mean? So how do you reach it if seated at the desk - it's on the other side of the cab! Aha - it's only out of reach if you have short arms!! ;D Having the flag raised on 'A' stock increases the top speed, but slows the acceleration rate as Q8 has said. With reference to 'flags up' at Aldgate, this is because drivers often put it up just before leaving the cab - so it's ready for the next departure from Amersham/Watford/Uxbridge. Metropolitan drivers like to think ahead!  It certainly is possible to raise or lower the flag switch while driving (even with short arms!!) but only if you are standing up at the time. When running late, the flag can be lowered (for good acceleration from rest) until the equipment gets into full parallel, and then raised again for maximum forward thrust! |
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Post by Deleted on Oct 26, 2005 6:28:02 GMT
It seems extracordinary that LT would spend money, over so long a period, on a feature that drivers were not supposed to use. At p 61 of "The 1938 Tube Stock" there is a picture of 38 TS coming into Kilburn southbound, according to the caption in 1950, with the WF flag clearly raised. So it would seem that practice sometimes differed from theory. ------------------------------------------------------------------------ Yes practice did differ from theory but you were strictly FORBIDDEN to use the weak field by regular and repeated warnings in the traffic circular.A driver could (and sometimes was) put on a disciplinary board if caught using it unauthorised. If you had been caught using in on repeated occasions you got the sack. As I said elsewhere the prohibtion was to save on current consumption (very much higher with the flag up) and also because the signalling did not take account of the higher speed you could attain with the WF operative. That could result in a rear end shunt in certain circumstances. So not a good idea. They did in the end remove the WF switch from some of the 38 stock after the second Tooting siding incident where the flag was found to be raised I beleive. So if a driver is mindful of his own safety and that of his passengers he'll leave the WF down where it's not meant to be used. If something untoward happens he'll be on a manslaughter charge. He-he, looks like Q8 has sneaked this post in while I was eating my breakfast!! ;D ;D Thinking back, I'm trying to remember if use of the WF was allowed on the outer sections of some lines. Certainly on the Piccadilly there were 'Flag Switch Up' signs at Acton Town WB and Arnos Grove EB (with 'down' signs going the opposite way) but not sure about other lines. 1959 stock (plus a few 38's and 62's) operated on the Piccadilly during the 1960s and early 70s, and all had working WF flag switches. Something that's making me smile now is remembering the way we all still called it "putting the flag up" on 73 stock in it's early days. There was no 'flag' at all -- just a rotary switch (and a Maltese Cross visual on the front of the train)!!  |
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Post by q8 on Oct 26, 2005 8:33:40 GMT
Well in my time you were NOT allowed to use the WF switch anywhere on the District line. Only 'R' stock had them anyway. The other two stock were gallopers without them.
On the other hand an 'R' stock had trouble dragging itself along without the WF switch up so all driver used it at all times. I did not like to use it in the tunnels so it was down at Bow Road and up at Hammersmith and vikky verki.
However to prevent it's use the board tried to pull a fast one. Two of the contacts on the switch were bridged out with a little metal strap so that even if you put the flag up the WF did not work. My wire cutters came in very handy then.
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towerman
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Post by towerman on Oct 26, 2005 20:04:33 GMT
The reason all stocks had a flag switch even though most lines didn't use them was an engineering one, it wasn't possible to get a sequence test light unless the flag was raised.
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Post by Deleted on Oct 26, 2005 21:07:38 GMT
Was it not authorised on the open-air sections of the Picc at both ends? The 73ts now has it permantly cut in, as when they werwe refurbed, they became somewhat heavier! There are a couple of sets out there that are a tad nippy, and have been in the situation before where my I/O has cut it out!!  |
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You say it's not a good idea in the city and that drivers have forgotten to put it down - but every train without exception has it up at Aldgate. I'm thinking that a flag raised on A stock has the opposite effect to a D stock - is that what you mean?
