Lights in Tunnels?

[heliumdesign]

I've been watching cab ride videos, like the one linked to below and am surprised there's no lights in the tunnels. In Boston there's lights throughout. Not bright enough to really see anything, but you can see the tracks, walls, etc. It seems that our headlights are brighter as well. Clearly the driver isn't "driving" so they're not necessary, but I'd think they'd want something so it's not staring into the dark most of the day.

https://www.youtube.com/watch?v=PmuU_zewbDE

 

[yorksrob]

Strange perhaps, but our drivers didn't have headlights until recently (1980's I think).

 

[Dstock7080]

Traditionally lights on the front of Underground trains was purely to mark the front end. Forward vision for the driver was never a consideration.
Even trains since 1967 which have dual headlights forward vision is very poor.
Only since the advent of '09 Stock and S Stock have their more powerful headlights have drivers finally been able to see.

 

[Nym]

Traditionally lights on the front of Underground trains was purely to mark the front end. Forward vision for the driver was never a consideration.
Even trains since 1967 which have dual headlights forward vision is very poor.
Only since the advent of '09 Stock and S Stock have their more powerful headlights have drivers finally been able to see.

Indeed, any new engineering vehicles are having significantly upgraded lights fitted as well, for example, see the D78 Rail Adhesion Train. They're bright lights...

 

[edwin_m]

Lights are installed in the LU tunnels and activated by the driver pinching the two bare wires on the tunnel wall together or connecting the emergency handset to them. This also turns off the traction power.

Most other underground networks internationally that I can recall have lights that are lit during normal service.

 

[Trackman]

Lights are installed in the LU tunnels and activated by the driver pinching the two bare wires on the tunnel wall together or connecting the emergency handset to them. This also turns off the traction power.

Most other underground networks internationally that I can recall have lights that are lit during normal service.

well I never knew it switched the traction power off too. I wonder how it works?

 

[Nym]

Detection relays, and a back contact on a relay connected across the traction supply.

 

[Daniel]

There are also ways of turning on tunnel lights without discharging traction current in case the track needs to be checked during traffic hours, etc.

 

[theageofthetra]

In the early days of the tube the walls were whitewashed on some lines each night. A contraption similar to one used to spray hops was attached to the back of an old motor coach with a shield to protect the conductor rail.


Haven't got the link to hand but a pic of it is on the Ianvisits site

 

[Mutant Lemming]

There are also ways of turning on tunnel lights without discharging traction current in case the track needs to be checked during traffic hours, etc.

Tunnel lights used to be switched on before the passage of the last train and switched off after the passage of the first train - usually done locally at each station.

 

[Daniel]

Tunnel lights used to be switched on before the passage of the last train and switched off after the passage of the first train - usually done locally at each station.

I would presume - (read: total guess) - that this practice was abolished when they stopped testing/using ration to station telephones?

 

[Taunton]

The Underground also seems to have a single light above every set of points in a tunnel - is this so the driver can see the lie of the points? If so the approach doesn't cover points outside tunnels during hours of darkness, which seems inconsistent.

 

[Dstock7080]

The Underground also seems to have a single light above every set of points in a tunnel - is this so the driver can see the lie of the points? If so the approach doesn't cover points outside tunnels during hours of darkness, which seems inconsistent.

If Staff need to secure them, there is a permanent light source.

 

[bramling]

The Underground also seems to have a single light above every set of points in a tunnel - is this so the driver can see the lie of the points? If so the approach doesn't cover points outside tunnels during hours of darkness, which seems inconsistent.

Even in hours of darkness it's rarely dark enough that one can't see the lie of points in the open. Tunnels are another matter however. It's not just so one can see what state the points are in, it also makes it easier walking to the points, for example if you're having to step over live rails etc. Normally you carry a torch with you though.

 

[WatcherZero]

Lights are installed in the LU tunnels and activated by the driver pinching the two bare wires on the tunnel wall together or connecting the emergency handset to them. This also turns off the traction power.

Most other underground networks internationally that I can recall have lights that are lit during normal service.

I thought the old metro practise was to have lights but they wernt turned on in normal service only at night after service ends so that maintenance workers could see.

 

[philthetube]

On the underground lights automatically turn on when power is off, however the power is taken off, I am not sure if this can be overridden. It is not fun driving with the lights turned on and having them flash past your eyes every few seconds.

 

[bramling]

On the underground lights automatically turn on when power is off, however the power is taken off, I am not sure if this can be overridden. It is not fun driving with the lights turned on and having them flash past your eyes every few seconds.

I don't think there's any way of overriding the lights coming on - although of course a technical officer could probably disconnect or bypass the relay.

Sometimes testing of the tunnel lights takes place overnight which results in them flicking off and on, staff would be warned to take torches with them. I remember an occasion when there was a defect with the tunnel lights around Camden Town which resulted in them being stuck on during traffic hours, but stuck off during engineering hours. A very surreal experience walking into an unlit tunnel, as despite having correctly tested for traction current being off, it still felt very unnerving.

 

[Peter Mugridge]

I don't think there's any way of overriding the lights coming on - although of course a technical officer could probably disconnect or bypass the relay.

If it's a single track tunnel like a deep tube it would be possible to avoid any problem by fitting shields to the lights that cover the side facing towards the train.

Might cost quite a bit to put such shields in, of course - and it wouldn't work if it was a two track tunnel like most of the sub surface system.

 

[philthetube]

If it's a single track tunnel like a deep tube it would be possible to avoid any problem by fitting shields to the lights that cover the side facing towards the train.

Might cost quite a bit to put such shields in, of course - and it wouldn't work if it was a two track tunnel like most of the sub surface system.

It would, but it would reduce lighting when needed and be very expensive to cover a rare eventuality which only happens rarely anyway.

 

[bramling]

If it's a single track tunnel like a deep tube it would be possible to avoid any problem by fitting shields to the lights that cover the side facing towards the train.

Might cost quite a bit to put such shields in, of course - and it wouldn't work if it was a two track tunnel like most of the sub surface system.

The problem with that is the lights are deliberately designed so that they illuminate the inside of cars. This is an important fall-back if a train breaks down or gets stuck off current and ends up with no interior lighting for whatever reason, which although a rare situation can happen. There are, for example, train defects which can put parts of the train into darkness - even though in theory there should be a small amount of emergency lighting. Meanwhile, of course, batteries can run out if the train is stuck long enough.

 

[Peter Mugridge]

The problem with that is the lights are deliberately designed so that they illuminate the inside of cars. This is an important fall-back if a train breaks down or gets stuck off current and ends up with no interior lighting for whatever reason, which although a rare situation can happen. There are, for example, train defects which can put parts of the train into darkness - even though in theory there should be a small amount of emergency lighting. Meanwhile, of course, batteries can run out if the train is stuck long enough.

Shielded on one side only would still allow illumination to enter the carriages from the other half of the lights, i.e. the bits that you have just gone past.

 

[Nym]

Shielded on one side only would still allow illumination to enter the carriages from the other half of the lights, i.e. the bits that you have just gone past.

So what about all the bi directional sections of track?

 

[Peter Mugridge]

So what about all the bi directional sections of track?

I mentioned in reply #18:

Might cost quite a bit to put such shields in, of course - and it wouldn't work if it was a two track tunnel like most of the sub surface system.

 

[BelleIsle]

I am sure that on one of the Video125 Underground cab rides the commentary states that TfL put the lights on especially for their recording.

 

[Daniel]

I am sure that on one of the Video125 Underground cab rides the commentary states that TfL put the lights on especially for their recording.

Yes -I had to arrange to have them switched on between Kings Cross and Angel for the passage of a train in relation to the filming for the latest (Channel 5) series of The Tube.

 

[bramling]

Yes -I had to arrange to have them switched on between Kings Cross and Angel for the passage of a train in relation to the filming for the latest (Channel 5) series of The Tube.

Not for the Video 125 ones, he uses additional lighting - for the Tube tunnels at any rate. Personally I think the second Central Line one was rather spoiled by using LED lighting, which means the view is very different to what the driver sees. Perhaps if the 92 stock ever gets LED headlights then the video will look right then!

Always enjoy watching the Northern Line one with the old signaling and 59 stock, although it's a shame it couldn't have been done with the first part filmed from a 59 stock and the second part from a 72 stock. Having said that what was done isn't bad at all - at least three of the drivers shown are still on the line today. As an aside it's also mildly amusing to see how much speeding there was in those days!