underground train lighting

[tube10]

Does the lights in the underground trains blink off and on when they go on a curve,slope and etc?secondly what type of fluorescent lighting are used on the underground trains?Finally which underground train model introduced fluorescent lighting in history?

[Deleted]

I *think* that the 1959 tube stock was the first stock to have flourescent lighting.

The lights in train carriages do flicker on and off partly when crossing points or other gaps in the conductor rail.

[agoodcuppa]

The first underground trains to have flourescent lighting was the "R" stock in (IIRC) 1947/8. Not only were they the first on LT they were, I think, the first in the UK.

Car lighting is supplied from on board generators or alternators which are driven by motors from the traction current. When a car goes over a traction current rail gap, or a set of points, there is no power to the generator and so the light dip for a few seconds.

It used to be the case that all the lights in one car were fed from that car so when the car "went off juice" all the lights went out. Trailers were fed from the adjacent motor car.

On and from 1973 stock each alternator feeds the lights along one side of the unit so that only half the lights go out.

[marty]

Incidentally, I´m starting to get annoyed by the fact that whenever someone mentions "Incidentally" you get the Rob Curling nod!

Yours Incidentally

M. T.

[Ben]

There were also the two experimental cars of converted met T stock that had fluorescent lighting; can't remember the dates off the top of my head though!

The lighting is fed @ 110v, and *i think* 850Hz on most stock.
Ive always wonderd if they are just standard american fluorescent tubes that have got a current of increased oscillation.

[Phil]

benedict said:

There were also the two experimental cars of converted met T stock that had fluorescent lighting; can't remember the dates off the top of my head though!

They were the A-stock prototypes 17000 and 20000.
1946-53.

[solidbond]

benedict said:

There were also the two experimental cars of converted met T stock that had fluorescent lighting; can't remember the dates off the top of my head though!

The lighting is fed @ 110v, and *i think* 850Hz on most stock.
Ive always wonderd if they are just standard american fluorescent tubes that have got a current of increased oscillation.

Actually 115v AC , at least up to and including D stock (Gawd knows what this new fangled modern stock uses ;D ;D)

[mandgc]

'A Stock Prototypes' ( Phil # 6)

Having Air Doors they required an extra Guard to operate them. He was in an adjoining Control Trailer.
17000 had most of the seats in the centre with very few window seats. That did not last long(!) and it was rebuilt more in the A stock style.

[Phil]

solidbond said:

benedict said:

The lighting is fed @ 110v, and *i think* 850Hz on most stock.
Ive always wonderd if they are just standard american fluorescent tubes that have got a current of increased oscillation.

Actually 115v AC , at least up to and including D stock (Gawd knows what this new fangled modern stock uses ;D ;D)

Both of you are/were right. Up till a few years ago UK single phase power was supplied at 240V and 110V a.c. before rectification.

Then the ****** EEC interfered. They wanted us to get rid of 240V but for once our Gov't said NO. The rest of Europe ran on 115V, so our 110V became 115V, but in an act of supreme spite they enacted a law that all mains supply was 115V or MULTIPLES of it. So we still had to change our 240V to 230V (apparently we couldn't argue this one).

Bottom line is - the lighting was 110V but became 115v (no changes to components needed) to satisfy the EEC.

[Tomcakes]

Yes, but it does make sense to have a standardised voltage...

[solidbond]

rbruce1314 said:

solidbond said:

Actually 115v AC , at least up to and including D stock (Gawd knows what this new fangled modern stock uses ;D ;D)

Both of you are/were right. Up till a few years ago UK single phase power was supplied at 240V and 110V a.c. before rectification.

Then the ****** EEC interfered. They wanted us to get rid of 240V but for once our Gov't said NO. The rest of Europe ran on 115V, so our 110V became 115V, but in an act of supreme spite they enacted a law that all mains supply was 115V or MULTIPLES of it. So we still had to change our 240V to 230V (apparently we couldn't argue this one).

Bottom line is - the lighting was 110V but became 115v (no changes to components needed) to satisfy the EEC.

Not sure how many years ago you are talking about, but I can assure you that the 1962 stock were using 115vAC from the start to supply the main car lighting . This was provided from the 230vAC from the Alternator (at 850Hz!)

[Tom]

rbruce1314 said:

Bottom line is - the lighting was 110V but became 115v (no changes to components needed) to satisfy the EEC.

But as it was on a train, derived from a 630v DC supply and not part of the mains electricity supplys therefore surely the EU ruling would not apply?

[Phil]

tom said:

rbruce1314 said:

Bottom line is - the lighting was 110V but became 115v (no changes to components needed) to satisfy the EEC.

But as it was on a train, derived from a 630v DC supply and not part of the mains electricity supplys therefore surely the EU ruling would not apply?

Quite true: stuff reconverted to AC by inverters from DC mains would indeed be down to the engineers involved and nobody else.

Admits to total brain failure and runs away to hide

[towerman]

The one exception to the 230 stepped down to 115 rule are the first 52 units of 67TS which have English Electric MA's which produce 58v AC stepped up to 115v AC.

[Deleted]

rbruce1314 said:

Both of you are/were right. Up till a few years ago UK single phase power was supplied at 240V and 110V a.c. before rectification.

Then the ****** EEC interfered. They wanted us to get rid of 240V but for once our Gov't said NO. The rest of Europe ran on 115V, so our 110V became 115V, but in an act of supreme spite they enacted a law that all mains supply was 115V or MULTIPLES of it. So we still had to change our 240V to 230V (apparently we couldn't argue this one).

Wot??? Europe runs on 240 volts (or close to that), same as UK. It's North America that uses 110 volts.

[Ben]

Its slightly more complicated than that; but yes. America uses 110-127v (and 208-240v; dont ask!) whereas most of the rest of the world uses 220-250v for NORMAL domestic voltage.

en.wikipedia.org/wiki/List_of_countries_with_mains_power_plugs%2C_voltages_%26_frequencies

With AC systems though, the electricity is distributed through three phase circuits. As far as I can tell this means you get three positive lines, each 120 degrees out of phase with each other aswell as a neutral line. Depending on the inter-phase voltage other line voltages can be obtained too.

[Dmitri]

benedict said:

With AC systems though, the electricity is distributed through three phase circuits. As far as I can tell this means you get three positive lines, each 120 degrees out of phase with each other aswell as a neutral line.

More precisely, a three "phase" lines (with AC, there is no "positive" or "negative"). And if you load all 3 phases equally, you don't need a neutral wire .

[Hutch]

110-127v (and 208-240v; dont ask!)

;D

Single phase voltage to ground in North America is nominally 120V – I’ve also measured this voltage myself. Domestic supplies are a ‘twin’ phase, centre tapped system with two 120V supplies 180º out of phase with each other.

For the record, North Americans insist on calling this a single phase system hence my ‘twin’.

For high wattage devices, usually stoves, driers and water heaters (plus all the electric gear that I brought in from outside of the USA) the two phases are tapped to supply 240V, i.e. there is no neutral.

In industrial systems, the system is three phase with each phase 120V to ground. In this situation, high voltage devices tapping two phases will only receive 208V due to the phase angle being 120º and not 180º. This I have also measured, and it made my UK kettle work considerably slower at work than it did at home (a 25% drop in power).

Now to our much maligned EU. Voltage in the UK is still 240V and in most of Europe it is still 220V – it is just that our harmonised EU voltage has been called 230V! This was achieved in the UK by a simple expedient of altering the tolerances on the nominal voltage from 240V ± 6% to 230V (-6%/+10%), i.e. nothing needs to change! I suspect Europe did the same but the other way around.

The older European domestic supplies (some are still about) were provided as three phases, each at 127V to ground. When one taps two of these at a phase angle of 120º, you get a supply at 220V with no neutral – a bit like the US. It also explains why Schuko plugs as used in Europe can go in anyway around as historically there was no polarity to be concerned about. Likewise a lot of European domestic equipment switched both phases of supply - instead of just the live, as in the UK.

[Ben]

Very true; if the loads are balanced on all three phases then no neutral is needed. The distribution is without a neutral, which is created at a star-delta connection. I managed to model this on a program called Crocodile Clips. It took ages to get it working properly but was very fun!
Hutch, do you have much of a problem with the differancies in frequency, or do you just use appliances that dont have motors in them? Cos I've read about the side effects on the internet, yet a friend of mine who flys there quite a bit says that hes never found a problem with motored 240volt 50Hz equipment being used on a 240volt 60Hz supply

[Hutch]

With most of my workshop equipment there was no problem – induction motors merely ran 20% faster. In case of the grinder it ran sweeter on 60 Hz than on 50 Hz. Even at the increased revs the grinding wheels were well in speed spec. – I checked! The bench drill ran faster and would not run on its highest setting – it stalled as it could not keep up with the phase dynamic. We took no white good to the US as fridges, washing machines etc. – especially those with timing devices - would not be happy. A friend took at 230V 50 Hz washing machine to 230V 60 Hz Brazil and it did not work.

Motors with brushes (B&D drill) behaved no differently. Transformers are more efficient on the higher frequency. It does not necessarily work in reverse and some US wall transformers (chargers etc.) run very hot on a 120V 50 Hz supply.

[frimm]

rbruce1314 said:

Both of you are/were right. Up till a few years ago UK single phase power was supplied at 240V and 110V a.c. before rectification.

hhhmmmm brings back memories of the very late 60's when my then newly married sister moved into a very old block of flats (long since demolished) just off Deptford High Street. The supply voltage was 110v and the lightbulbs could only be bought in one shop.

Current available was extremely limited and the TV etc needed step up transformers. Dunno where the power was generated though.

[Deleted]

I can remember a time when Finchley still had the power supply put in by the Finchely Borough Council, which provided DC. My grandparents had a very early television, and they had a small rotary converter on top of a cupboard in their kitchen to provide 240v AC for the TV.

Early in the 1950s, Finchley was brought into the National Grid system and the DC was replaced with 240v AC. All the lights worked fine, so presumably the DC was also at 240v.

[frankpick]

I used to love the sound of the "MG On" flag indicator operatred by solinoid going up and down on 59TS. It was especially noisy at coming out of the old Hounslow West, Cockfosters and the crossover to Northfield EB from Boston Manor.

Can't remember the unit number, but there was an experimental capacitor on one that preveneted it from flapping - only going to the off position when the MG ran down.

The lights would dim going over all the above as the MG was running down. The only lights left were the emergency 50V bulbs at the end of each carraige.