Train, do you know where you're going?

[Deleted]

Earlier today, I'm peggin' it down from Snaresbrook into Leytonstone, and I become aware of a message on the DTS screen:-

ATO Map Data Not Available

Hmm. well, I know where I'm going, even if you don't. Never had that one before. I thumbs through the in-cab Defect Handling Guidelines, and I am led to beleive it could be a partial ATO failure. Any case, I'm not taking any risks, so I gets on the blower at Leytonstone and tell the guv'nor. He arranges for the train to be 'looked at' at end of the unit's traffic day. While I'm waiting for the stick to clear, I make a note in the Defect Log. I then shut down the train, remove my key and wait a minute or so. Get a punter ask "Why ain't yer goin?" I points at the signal and ask him what colour it is. He dissappearss from view. Stick pegs up, so i puts me key back in and sets off. I had no further problems.

[Phil]

Hope you managed to leave punter behind! ;D ;D ;D ;D

NOBODY likes a smartarse!

[Deleted]

I love on-board computer systems! The Volvo B7Ls that I used to drive would often flash up random defect warnings, accompanied by a synthesised dinging noise. The only way to stop this would be to thump the top of the dash panel with a ticket roll

[Deleted]

The 92ts dos havea habit of doing such things, flashes up messages, then when you take you key back out and put it back in, you never see the message again.

I think its also known as "spurious"!

rbruce1314 said:

NOBODY likes a smartarse!

Too right........

[Deleted]

As with most tempremental electronic equipment, if it throws a wobbly, switch it off, turn it back on, and it usually works. Of course this is a bit annoying if the computer runs the Jubilee's signalling system!

[Deleted]

Other messages I've had appear on the monitor:

Brake Not Available [ ]
Motoring with Brakes Applied [ ]
Motoring with Brakes Released [ ]
PEA Operated, Car 8 [ ]

Train Entered Prohibited Area [ ]
Wondered why I was reading platform signs saying Uxbridge ;D ;D

Spurious indeed MA!

[Deleted]

Train Entered Prohibited Area??? Where, realistically, would this be used? What situations??

[Deleted]

sturdjos said:

Train Entered Prohibited Area??? Where, realistically, would this be used? What situations??

When ATO was being introduced on the Central, it wasnt done all at one time, it was done in sections. This happened alot during this time. Also, you *would* gets this message if you tried to enter the depot's in ATO mode.

[Deleted]

Oh i see

When did the Central begin to get automated??

Oh - BTW, why are lines automated??

[Phil]

Why are they automated?

As t/op92 will say, it's a case of speed. No human would DARE drive a train the way a computer can. It takes everything (acceleration, last-second braking ) to the limit and so allows more trains per hour.

[Deleted]

Oh - so its a case of having a better, more reliable, more frequent service then. I had it figured it would be something like that.

Cheers Phil

[Deleted]

rbruce1314 said:

Why are they automated?

As t/op92 will say, it's a case of speed. No human would DARE drive a train the way a computer can. It takes everything (acceleration, last-second braking ) to the limit and so allows more trains per hour.

Ahh, you 'it the nail on the 'ead there buddy!!!
ATO can drive the train to its full potential, and use the full accellerating and braking capabilities. Thats why when on the Central, and you're right up behind the T/Op, it appears that the braking is being left until the extreme last moment, and then there's the sharp pull away from the station. Excellent when it works; nightmare when it goes wrong [which I must admit, is happening much less often now] Sometimes the ATO system will just ever-so-slightly under/over-run the PAC.

[Deleted]

tubeoperator92 said:

Brake Not Available [ ]
Motoring with Brakes Applied [ ]
Motoring with Brakes Released [ ]
PEA Operated, Car 8 [ ]

Train Entered Prohibited Area [ ]

I have seen "Motoring with braks released" as well, which amused me! ;D. One of the days I spent with a WER IO, the train went defective up at Epping, I remember all sorts of strange messages appeared, I cant for the life of me remember what they were. I seem to remember "Motoring with EMCy brake applied" - Strange!! ;D

Bring back the 62s

[edb]

tubeoperator92 said:

Ahh, you 'it the nail on the 'ead there buddy!!!
ATO can drive the train to its full potential, and use the full accellerating and braking capabilities. Thats why when on the Central, and you're right up behind the T/Op, it appears that the braking is being left until the extreme last moment, and then there's the sharp pull away from the station. .

Now correct me for being very wrong but was this not the cause of the derailments on the Central line (Chancery Lane and the other one i cannot remeber)?

IIRC The cause of the motor mounting failures was that the computer pushed the motors so hard on accelaration that it put more stress on the mounts that was usually found on LU and as such actually broke the mounts caused the motors to fall out and as such caused the derailments.

It was a long time ago since i read the report that i have forgotten half of it.

[Deleted]

edb said:

tubeoperator92 said:

Ahh, you 'it the nail on the 'ead there buddy!!!
ATO can drive the train to its full potential, and use the full accellerating and braking capabilities. Thats why when on the Central, and you're right up behind the T/Op, it appears that the braking is being left until the extreme last moment, and then there's the sharp pull away from the station. .

Now correct me for being very wrong but was this not the cause of the derailments on the Central line (Chancery Lane and the other one i cannot remeber)?

IIRC The cause of the motor mounting failures was that the computer pushed the motors so hard on accelaration that it put more stress on the mounts that was usually found on LU and as such actually broke the mounts caused the motors to fall out and as such caused the derailments.

It was a long time ago since i read the report that i have forgotten half of it.

There were many factors that caused the Chancery Lane derailment, one of which was the ATO system used. The Central Line uses "Distance To Go" ATO, which reduces the trains speed in steps as the train approaches the train in front or another stopping point. The ATO system is also configured for the train to run by default on 100% power. This results in the train constantly accelerating and decellerating which puts a lot of stress on the motors and gearbox.

More advanced ATO systems such as Moving Block have a smoother decceleration curve as a train approaches the train in front, putting less stress on the motors and gearbox. Some Moving Block systems don't usually run the train on 100% power, that is reserved for when the train is running late by more than a specified amount of time.

The Victoria Line, and SSLs new signalling will be "Distance To Go" based. However, many "Distance To Go" signalling systems run in many other metros (notably Hong Kong MTR) without motors falling off the trains. This makes me thing that train design, and the maintenance regime were also to blame.

[edb]

I was going to amend my post to say that design also was probably a major factor. I suspect the stress modeling, computer simulation etc was less advanced at the time these units were designed. It probably relied much more on human calculations and error more so than nowerdays, (i did two years of a mech eng degree, it was tough with a capital T).

However maintainance is something i have no basis to have a view on - not that this is a view, mnore a broadening of my understanding.

[Deleted]

Soon after the Chancery Lane derailment, some techno--gizmo was installed on a test train, to measure the force put on the motors under accelleration; I can't remember exactly what was quoted, but it had a few zero's on the end!

[Phil]

edb: you've hit on a very important point.

Design engineers design something that they think (hope?) will work, using the aids of computers etc these days.

However, once in service it is down to MAINTENANCE engineers (and technicians) to see if all is going according to plan. If not the maintenance (production)engineers have to design and implement modifications

As an example look at the 323s which kept dropping transformers when new. It was something the design engineers could never have envisaged.

So, back to the Central, one of the first jobs to go under cost-cutting is often the production engineer (I don't know if this is true in this case), so the design is never properly evaluated in full service conditions.
Somebody should have been checking the strength and tightness of the bolts to see if they were overstressed. One way or another this did not happen and the rest we know.

Whatever the design, it was the maintenance issue that caused the problems on the Central