What the hell do these things do on the tube? | Net Of The Woods

2013-08-18 16:34:55

thatsTheSpirit
Joined: 2013-08-02 16:00:05
Posts: 20

Interestingly, a large amount of the braking on a 1996 Tube Stock train is done electrically, with the train's motors. You'll see the air pressure on the gauge spike at the outset while the motors are kicking in, when it will plunge before rising again at about 5/10 mph, when the motors can no longer give a braking force.

I might have lied when I said interestingly.

No, that's interesting.

Can you illustrate the various types of power controllers in use, and traction motor technologies? I'm quite good at picking them out by sound, and can put a dinner party to sleep recounting them.

Errr, I might have used the same way you did, actually.

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2013-08-18 16:47:55

jexxub
Joined: 2013-08-02 16:37:42
Posts: 18

Brake cylinder pressure gauges.

You might see the knob move when the brakes are functional as the pressure increases.

They are evident so that the driver can inspect them in a hurry if there is a snag with the brakes -- as the hand would show pressure where perhaps there shouldn't be any.

Do contemporary trains have this? It would appear to make more sense to show up on a display in his cab, rather than in the carriage itself.

> Do contemporary trains have this?

What sort of train do you think is in the photo?

Central line.

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2013-08-18 21:04:55

firemaid
Joined: 2013-08-04 17:32:06
Posts: 13

Brake cylinder pressure gauges.

You might see the knob move when the brakes are functional as the pressure increases.

They are evident so that the driver can inspect them in a hurry if there is a snag with the brakes -- as the hand would show pressure where perhaps there shouldn't be any.

Do contemporary trains have this? It would appear to make more sense to show up on a display in his cab, rather than in the carriage itself.

> Do contemporary trains have this?

What sort of train do you think is in the photo?

Is it a Jubilee line?

Aka - not an older train.

Aren't they over 15, just about 20 years old?

In train terms, that's not old though.

How long does one last? 50 years?

The Isle of Wight's railway uses tube stock from 1938, which is now edging 75 years old. They're apt to last well clear of their 80th birthday.

If you maintain it relatively well, an electric train will nominally keep going forever. (The Buenos Aires metro has just completed phasing out the last of the original rolling stock from Line A, which, at its withdrawal, was 100 years old in standard revenue service.)

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2013-08-19 01:23:55

ninjaprancing
Joined: 2013-07-30 13:59:15
Posts: 21

Brake cylinder pressure gauges.

You might see the knob move when the brakes are functional as the pressure increases.

They are evident so that the driver can inspect them in a hurry if there is a snag with the brakes -- as the hand would show pressure where perhaps there shouldn't be any.

Do contemporary trains have this? It would appear to make more sense to show up on a display in his cab, rather than in the carriage itself.

They have them on the brand new H&C/Circle/District trains. The underground trains don't get any newer than that.

Have noticed them there alright, but am also curious as to why they're in a customer-facing area?

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2013-08-19 02:53:55

wackysimply
Joined: 2013-08-04 17:32:25
Posts: 5

Interestingly, a large amount of the braking on a 1996 Tube Stock train is done electrically, with the train's motors. You'll see the air pressure on the gauge spike at the outset while the motors are kicking in, when it will plunge before rising again at about 5/10 mph, when the motors can no longer give a braking force.

I might have lied when I said interestingly.

No, that's interesting.

Can you illustrate the various types of power controllers in use, and traction motor technologies? I'm quite good at picking them out by sound, and can put a dinner party to sleep recounting them.

Errr, I might have used the same way you did, actually.

Since the demise of the A stock on the Met, operators drive the train using Combined Traction Brake Controllers. On older train stocks they are notched, but because the Central/Waterloo and City 1992 Train Stock they have been continuous. A couple of links will provide you with all you'll ever need to know regarding the underground - District Dave and Tubeprune

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