Brake Testing and related matters

[joeltancl]

Dear Members

There are photographs on the Web showing refurbished 1967 Tube Stock with what appears to be a brake test indication panel similar to that retrofitted to C Stock.  

When the 67TS were in unrefurbished state how was the brake test performed? Also how was the brake test done on 1972 Stock (all the Mark II units and the sole Mark I unit) converted for one-person operation prior to refurbishment? 

Apologies, if these have already been asked elsewhere or are not allowed to be discussed in this forum.

[towerman]

ATOs had duties that consisted of assisting with prep on a certain number of trains entering service.The ATO taking the train into service would charge up the train line then put the CTBC into lap,the assisting ATO would walk through train making sure the PA was working in all cars,when he got to the rear cab he would contact the ATO in the leading cab he’d then operate the emergency brake handle to drop train line pressure.When pressure was exhausted he’d put the handle back to release and check with the leading cab the train line had dropped,the leading ATO would then put the CBTC back to off & release,both ATOs would make sure the train line recharges both ends the the rear ATO walks back checking that brakes have released on all cars.Hope that helps.

[joeltancl]

So, very similar to the procedure used on OPO C Stock before the panel was retrofitted, with the assisting driver taking the place of the Guard...

Thanks towerman!

[jimbo]

To avoid the assisting ATO rostered to join each train for preparation, there was talk of the original ATO doing an extra return walk through the train to check the air was exhausted throughout, then recharge and walk through to check it was released thoughout again. Whilst the assisting ATO method worked on the Victoria Line as trains entered service over a period of time, it was feared that lines like the Northern Line had many trains entering service in a short period of time, so many assisting ATOs would need to be rostered at each location. 

To check the PA worked through the train, before a test sound was installed, the windscreen wiper was turned on in the cab to provide a sound to hear through the train!

[towerman]

Forgot that bit,they used to hang the handset over the sun visor!

[joeltancl]

May 22, 2023 20:26:35 GMT jimbo said:

Whilst the assisting ATO method worked on the Victoria Line as trains entered service over a period of time, it was feared that lines like the Northern Line had many trains entering service in a short period of time, so many assisting ATOs would need to be rostered at each location. 

To check the PA worked through the train, before a test sound was installed, the windscreen wiper was turned on in the cab to provide a sound to hear through the train!

As for the Northern Line, am I correct to say that this discussion would have been in the context of the 95TS?

[jimbo]

No, I think it was an example of other lines in the early years of the Victoria Line. The Vic. Line changed to one person train preparation early on, before other lines became one-person operated. So I suppose other lines followed that example. There must have been early thoughts of other lines following the Victoria Line into auto-operation. I know the C stock was designed for conversion as soon as resignalling was completed. That has only recently been done for the Circle and H&C, and the Wimbledon branch seems as far off as ever! 1972 stock was intended for auto-operation on the Jubilee Line, but the money was not forthcoming. 1973 stock was to be converted upon resignalling, which is still beyond the budget!

[Dstock7080]

When undertaking a brake test as a Guard, assisting T/Op or T/Op I always understood that you shouldn’t discharge the trainline fully but heavily reduce and wait until the pressure remains steady after reducing.

[towerman]

That’s right they used to drop it to around 10psi then hold it for short while to make sure train line held steady no leaks.

[joeltancl]

May 23, 2023 5:07:00 GMT jimbo said:

No, I think it was an example of other lines in the early years of the Victoria Line. The Vic. Line changed to one person train preparation early on, before other lines became one-person operated. So I suppose other lines followed that example. There must have been early thoughts of other lines following the Victoria Line into auto-operation. I know the C stock was designed for conversion as soon as resignalling was completed. That has only recently been done for the Circle and H&C, and the Wimbledon branch seems as far off as ever! 1972 stock was intended for auto-operation on the Jubilee Line, but the money was not forthcoming. 1973 stock was to be converted upon resignalling, which is still beyond the budget!

And, as things turned out the '56/'59/'62 Tube Stock were never converted for OPO ... 

 

[joeltancl]

May 23, 2023 7:29:29 GMT Dstock7080 said:

When undertaking a brake test as a Guard, assisting T/Op or T/Op I always understood that you shouldn’t discharge the trainline fully but heavily reduce and wait until the pressure remains steady after reducing.

Why did they not discharge the trainline to zero? Was it merely to save time when recharging it, or were there other reasons?

[towerman]

To make sure there was no train line leaks.

[rincew1nd]

May 23, 2023 15:39:21 GMT joeltancl said:

May 23, 2023 7:29:29 GMT Dstock7080 said:

When undertaking a brake test as a Guard, assisting T/Op or T/Op I always understood that you shouldn’t discharge the trainline fully but heavily reduce and wait until the pressure remains steady after reducing.

Why did they not discharge the trainline to zero? Was it merely to save time when recharging it, or were there other reasons?

Decreasing but not emptying makes the process quicker, but also when the brake controller is in 'lap' it should neither charge nor discharge the brake pipe - dropping it to a point makes it easier to see if it is either rising or falling when it should actually be steady.

[jimbo]

May 22, 2023 20:26:35 GMT jimbo said:

..... Whilst the assisting ATO method worked on the Victoria Line as trains entered service over a period of time, it was feared that lines like the Northern Line had many trains entering service in a short period of time, so many assisting ATOs would need to be rostered at each location. .....

I don't know how the lines worked fifty years back, but looking at the current working timetables, the Vic Line service has built such that 5 trains enter service in the quarter hour to 6:15, whilst Morden Depot puts into service 5 trains in a quarter hour on four occasions through the morning build up, 9 in half-hour periods from 5 to 6:45 which the Vic Line never reaches, even 10 from 5:30 to 6:00.

[joeltancl]

May 23, 2023 20:01:53 GMT rincew1nd said:

May 23, 2023 15:39:21 GMT joeltancl said:

Why did they not discharge the trainline to zero? Was it merely to save time when recharging it, or were there other reasons?

... but also when the brake controller is in 'lap' it should neither charge nor discharge the brake pipe - dropping it to a point makes it easier to see if it is either rising or falling when it should actually be steady.

Ah, so the whole point of the test is to ensure not only that the brake pipe (B.P.) / trainline is continuous throughout the entire train, but also that there is no leakage anywhere in the B.P./trainline. Thanks rincew1nd and towerman !

[joeltancl]

May 24, 2023 1:02:25 GMT jimbo said:

May 22, 2023 20:26:35 GMT jimbo said:

..... Whilst the assisting ATO method worked on the Victoria Line as trains entered service over a period of time, it was feared that lines like the Northern Line had many trains entering service in a short period of time, so many assisting ATOs would need to be rostered at each location. .....

I don't know how the lines worked fifty years back, but looking at the current working timetables, the Vic Line service has built such that 5 trains enter service in the quarter hour to 6:15, whilst Morden Depot puts into service 5 trains in a quarter hour on four occasions through the morning build up, 9 in half-hour periods from 5 to 6:45 which the Vic Line never reaches, even 10 from 5:30 to 6:00.

Perhaps then it was fortunate for the Northern that O.P.O. was never introduced there till the 95TS came on stream ... 

[jimbo]

May 24, 2023 1:02:25 GMT jimbo said:

May 22, 2023 20:26:35 GMT jimbo said:

..... Whilst the assisting ATO method worked on the Victoria Line as trains entered service over a period of time, it was feared that lines like the Northern Line had many trains entering service in a short period of time, so many assisting ATOs would need to be rostered at each location. .....

I don't know how the lines worked fifty years back, but looking at the current working timetables, the Vic Line service has built such that 5 trains enter service in the quarter hour to 6:15, whilst Morden Depot puts into service 5 trains in a quarter hour on four occasions through the morning build up, 9 in half-hour periods from 5 to 6:45 which the Vic Line never reaches, even 10 from 5:30 to 6:00.

Having reviewed all current working timetables, I presume that the Northern Line was picked for comparison as Morden provided the most intense injection of trains into service. Upminster Depot provides five trains in a quarter hour on three occasions within 5:30 to 6:30, with 10 in the half hour to 6:00, but no 9 trains per half hour. Neasden and Cockfosters inject high rates into service but split between both depot ends.

The train injection rate is crucial to service build between the end of engineering hours and the start of the morning peak at 7am. Work was done on improving that at Northumberland Park by making the connection to Seven Sisters bi-directional, and has recently been completed at Neasden Depot in preparation for the Metropolitan line service boost upon resignalling. Proposals for Northern Line Upgrade 2 were restricted to a late peak commencement without expensive new track layouts at Edgware and High Barnet to avoid the double-shunt into service.

In reviewing trains entering service, I was surprised to note that Stonebridge Park depot only provides 9 trains for service, whilst the original London Road depot provides 11 and Queen's Park provides 7, with one starting from Elephant platform. Also, whilst the Central line has two major depots, Hainault provides 32 trains whilst Ruislip only provides 17, with 12 trains from White City sidings, 10 from Loughton sidings, 5 from Woodford sidings and one from Woodford bay platform.

[jimbo]

May 24, 2023 1:02:25 GMT jimbo said:

May 22, 2023 20:26:35 GMT jimbo said:

..... Whilst the assisting ATO method worked on the Victoria Line as trains entered service over a period of time, it was feared that lines like the Northern Line had many trains entering service in a short period of time, so many assisting ATOs would need to be rostered at each location. .....

I don't know how the lines worked fifty years back, but looking at the current working timetables, the Vic Line service has built such that 5 trains enter service in the quarter hour to 6:15, whilst Morden Depot puts into service 5 trains in a quarter hour on four occasions through the morning build up, 9 in half-hour periods from 5 to 6:45 which the Vic Line never reaches, even 10 from 5:30 to 6:00.

Hence the problem when a defective train comes south in the early peak. If it occupies a platform at Morden it halves reversing capacity, but if it works to depot it prevents all these trains from entering service. Could it perhaps be parked in Tooting siding for later return north? That probably depends upon the problem, where it becomes obvious, and how likely it will affect the service whilst running back north.

[jimbo]

How are Northern line trains prepared for service now? Does the driver walk through and then back, checking things before taking the train into service? Or do depot staff do this work before the driver arrives?

[Dstock7080]

Probably as most Lines now;
check for targets displayed
check for overhead leads inserted (depot staff remove)
board at rear
set switches lights etc for departure
Walk through train
check for targets displayed
set switches destination etc for departure
doors closed visual illuminated
undertake brake test.
not much else these days.

[joeltancl]

Then how were things done on the previous generations of Stock (56, 59, 62, 72/1 and 72/2 TS), with 2-person crews? How was the work divided?

[Dstock7080]

Driver dealt with cab and brakes, Guard with doors, lighting, interior condition etc.
Brake test undertaken together, with driver on the brake handle and Guard watching brake gauge and hand on passenger emergency valve.

[towerman]

Used to be the guard’s job to remove rear jumpers on trains entering service from shed roads,now done by rolling stock staff.

[jimbo]

I would have said that the work was divided with the Guard responsible for the passengers, so checking doors, lights, seating, graphiti, glass, etc. and the Motorman responsible for driving and stopping the train so controls, brakes, etc. But towerman reminds me that another split was between the front and rear of the train, with the Guard responsible for checking rear red lights, rear trip reset, etc. 

[roythebus]

It wasn't the guard's job to reset rear trip. Guard would check interior, heat (ha ha), lights, emergency candles, fire extinguishers, door controls, open and shut doors each side, check end door cut-outs work. Ensure oil tail lamp present at each end and had sufficient oil. Brake test would be done before departure using Loudaphone to contact driver, this checked brake pipe continuity as well as the Loudaphone. Check bell works. Check door open indicators on each car where fitted. Check where tea would be made on the way and where driver would leave tea can on the platform for guard to pick up.

[jimbo]

Correct, Guard cut out rear trip if operated enroute, leaving it to driver to reset on reversal.

[joeltancl]

On another note, was there a test to check that the electro-pneumatic (E.P.) brake was working?

[Dstock7080]

No, as most faults would be indicated by an “audible warning” which was a small air valve which opened to alert the driver.

[joeltancl]

I now see why such a test would be unnecessary. Thank you very much Dstock7080 !

[jimbo]

Jun 8, 2023 21:20:09 GMT jimbo said:

Correct, Guard cut out rear trip if operated enroute, leaving it to driver to reset on reversal.

Brings to mind that there was no problem with a train running with the rear trip cut out. The leading trip prevented a train from passing a signal at danger. The rear trip was a nuisance, inadvertently bringing a train to a halt if it hit an obstruction such as loose ballast or a discarded drink can. When LT was told by the Government to order new trains for the Northern Line within the week, the only recent tube train design was the auto-trains on the Victoria Line, and a consequence of the hurried design conversion that produced the 1972 tube stock was that the rear tripcock was automatically isolated upon reversal.

This appeared to be an advantage, but in practical operation produced a serious safety consequence when the combined traction/brake controller jammed, which happened from time to time. The driver was then required to operate the train from the rear cab in reverse, with the train guard riding in the leading cab as look-out. The guard had much less experience and might misread the signals ahead, but the tripcock became automatically isolated as it was then the opposite end to the operative cab!

Of course, there was a hurried purchase of a second batch of this stock in advance of the Jubilee Line opening, when Metro-Cammell were left with an empty order book until the 1973ts design was completed. This feature was designed out of the 1973ts and following stocks. Was it ever fixed on the 1972ts?