[OT] London Underground Trains

I read somewhere that shorting them three times in quick succession was the signal for the power to be shut off. That was to allow station staff to signal it in an emergency, even if they could not contact the signal box.

The following link (and the rest of the site) is a good read about the technical bits of the london underground,

The District Line had larger carriages and stopped at Ravenscourt Park, Turnham Greem and Chiswick Park between Hammersmith and Acton Town. Sometimes went on to Hounslow.

Interesting, thank you.

These differences from earth are maintained loosely, so that if one of the power rails gets grounded by debris or a fault, the 630V between them is still maintained. A grounding fault is detected by the power feeds to the track, and detectors onboard the trains, so that it can be fixed during maintenance hours.

Some interesting info in this old video...

Welcome back Andrew! Some of us had wondered about your absence here. Happy New Year...

Jon N

It isn?t generally mentioned too much that it also makes extracting from under a train the bits of those whose attempt was successful or the really unfortunate ones who failed to make it completely into the pit and suffer what are nowadays coyly called life changing injuries. The clearance under the smaller sized tube trains is minimal with the platform and offside tunnel wall making side access very difficult and not all jumpers get fully clear of the rails and wheels at the side of the pit with some ending up straddling the centre negative rail which as others have noted is a relatively low 220 volts to ground so dry clothing will probably prevent electrocution but the collector shoes catch them and cause traumatic injuries as they do so . The staff and emergency personnel who have to attend won?t really know what the state of the person is till they enter the pit themselves and make their way along under the train.

Drawing of how they were built originally without pit.

The pits were created in the 1930?s after the formation of London Transport who took over the former company run lines, some sources say they were originally intended to collect water leakage at a couple of troublesome locations but the usefulness in saving some lives or dealing with the aftermath under a train soon became apparent so they got installed at every LT tube* station that was underground and in use. A couple of disused platforms like the one at Aldwych had no cause to be and that mainly remains as built now disused for over a century .

More accessible examples that never had pits added so look a bit unusual are Waterloo and Bank stations on the line that connects them as though a tube line it was operated by British Rail and its predecessors till 1994 when it was transferred to the successor of London Transport, London Underground Limited who so far have not altered it.

GH

The very long serving 1930s rolling stock was from before the use of spring release brakes, it used air pressure to apply brakes, with the obvious safety issue. It's still in use on at least one of the islands. They also have a peculiar feature that brakes can be applied gradually, but can't be released progressively. The only way to reduce braking force is to release them completely.

What I never understood was why the lighting went on & off so many times on every journey.

I think that is when the train goes over points which mean a break in the centre power rail so the carriage you are in loses power temporarily.

Sometimes you only lose lights on one side of the carriage; I don't understand that.

The carriages are all wired in some parallel/series arrangement ?

Not all cars (The tubes were built with US influence and use their terminology ) had collector shoes only the motorised ones , adjoining trailer cars would be fed by jumper cables from a motorised car . To avoid all lights going out completely when a motorised car lost power over a conductor rail gap lights on each side of a set of cars would be fed from different power cars so you got the effect you were asking about of one side going out then coming back followed by the other side going out as the respective power cars crossed the gap. A few lamps never went out as they were connected to a battery. Nowadays they all stay on. While it might from the outside appear to beg the question why wasn?t there a circuit the whole length of the train there were rules drawn up in the

GH

I always wondered, now I know. I gather the 30s stock was retired for safety reasons, and I'm guessing it was flammability. I see the duckboard aka tinder floors are now removed/covered on the island line 30s carriages.

Was that a deliberate (but accurate) typo? [tinder]

Not a typo, no. Tinder is exactly what they were.

Thanks Jon.

I didn't have time to keep up with uk.d-i-y, and I still don't, so I just drop in occasionally to see what's happening. Also, I no longer use the desktop which had my preferred usenet client.

I just finished 3 years dealing with my own prostate cancer. I now do a lot of support of other prostate cancer patients and their partners, including 1-2-1, lectures, workshops, and running support groups. I was recently asked to teach a class to clinicians doing an MSc in prostate cancer care, which went extremely well, and it looks like I'll be doing more of that. A number of consultants and specialist nurses point patients to me, and I seem to have become quite an expert on some aspects of treatment such as hormone therapy and helping patients get through it. I also help out a couple of NHS CCGs and an NHS region with prostate cancer awareness. I've found I really enjoy this volunteering work.

Perhaps I should post an awareness thread here as most readers will be in the vulnerable age range?

Still do wiring, plumbing, home automation, software development, etc. and quite a lot of caring for parents in the last 5 years.

Regards Andrew Gabriel

Nice to see you back, even if only occasionally. Well done for the "good works". I passed my first (and only) finger test last year.

congratulations and applause

feelings of inadequacy you engender are not your problem :)

More importantly, is the Keston still going ?.

Yes, but only because I look after it carefully. Many boilers work fine without being serviced for years, but you wouldn't get away with that with the Keston. It is 20 years old now, but does still look brand new inside the case.

A contributory factor to longevity (by this boiler's standards) may be that the heating runs at about 45/35 most of the time because of fitting oversized radiators, although I do crank it up to 60 if I arrive home and had forgotten to switch the heating on remotely beforehand, and it does heat the house up from cold quite quickly. I did notice in the home automation logs that I can tell when it needs servicing. It usually takes 18 or 19 seconds to fire up from applying the demand signal to it. If this starts increasing to over 20 seconds, that's an indication it needs servicing. My home automation now alerts on noticing this.