Which lines/stock do the lights still go on and off when going over points

[A60stock]

I recall back in the day, on all stocks, the lights would go on and off for a moment whilst the train gapped momentarily. Where does this still happen? I know the bakerloo line is one of these on trains where the new LEDs havent been fitted yet

 

[kacper]

just the 72 stocks i think

 

[bramling]

I recall back in the day, on all stocks, the lights would go on and off for a moment whilst the train gapped momentarily. Where does this still happen? I know the bakerloo line is one of these on trains where the new LEDs havent been fitted yet

Piccadilly Line does. The newer stocks will still do it if the train stops in the wrong place for long enough.

 

[Dstock7080]

Stock with traditional Motor Generator/alternator MG/MA would run down when going over rail gaps, causing the main lighting to extinguish.
1973 Stock were fitted with static converters at refurbishment but the lighting circuit remains attached to the MA.
Only ‘72 and ‘73 Stock retain this quirk.

 

[Bigvernicus]

On the 73Tube stock the lighting will extinguish on one side only except for the emergency lights, as each side of the car lighting id fed from the DM MA set and the UNDM MA set, so is not so obvious unless both cars on the unit are over rail gaps, wheras on the 72 Tube stock the MA feeds a pair cars on the unit where both sides of lighting extinguish except for the emergency lighting.

 

[thomalex]

I thought the Bakerloo trains (well the ones that have had a recent refresh) were actually some of the only trains on the network with LED lighting along with maybe the 96 Stock on the Jubilee. Even the S Stock don't have LED lighting.

 

[Dmthomson]

I know when I driven 95 stock, if one end of my train wasn't getting juice then I'd lose half my lights 30 seconds later. I had it a few times southbound waiting over the points at Morden for the target point to advance into the middle platform when another train was departing Platform 5 to the depot.

 

[janahan]

I thought the Bakerloo trains (well the ones that have had a recent refresh) were actually some of the only trains on the network with LED lighting along with maybe the 96 Stock on the Jubilee. Even the S Stock don't have LED lighting.

Whilst having LED lighting is often desirable, its often a compromise. Remember traditional FL Tubes are still a lot more efficient than incandesent lights, with modern FL tubes and driving equipment reaching 80 to 100 lumens per watt (compared to 16 for incandesent, and 100 to 130 for LED white lights). The disadvantages of FL (apaprt from the energy) may be somewhat not applicable on train use:

• Warm Up time - since they are always on, not a real issue
• Disposal of hazardous waste - since railway companies have dedicated workshops, they are more likely to have proper facilities, and process at a reasonable cost
• lower lifetime than LEDs - balenced by being cheaper to replace tubes, and as stock is regularly maintained, the swapping canbe part of an ordidary schedule, and usually can be quicker than changing an LED

Also Tubes have one advantage over LEDS at the moment, the spread of ligh in all directions, LEDs can be still very directional, despite current advnaced in deflectors, and trying to defuse LEDS further impacts the lumens emmitted. Future research on Quantum Dots, as used on some TVs may prove fruitful. Tubes do however, provide a nice diffused and spread light by default, making it easier to fully illuminate a carraige. And this might actually be the real reason why the S-Stock still use FL?

I am sure the S-Stock has LED where a spot of light is needed, such as doorways, etc.

The bakerloo is being re-fitted with LEDs for probably other reasons, to avoid the issue of lights dimming at at power breaks (as LEDs are better buffered via a battery, or Super Capacitor)

 

[Bletchleyite]

Decent quality LED is not a compromise, it provides tungsten-quality light with little flicker at a comfortable colour temperature. I have it in my house and it's indistinguishable from tungsten other than that the dimmable bulbs dim without changing colour temperature whereas a tungsten bulb becomes a warmer colour at lower brightnesses.

Unfortunately, almost no railway applications have selected quality LED solutions, they've cheaped out, and as a result the light quality is usually utterly horrible, be that a nasty blue colour temperature, excessive brightness, excessive glare or flicker.

 

[janahan]

Decent quality LED is not a compromise, it provides tungsten-quality light with little flicker at a comfortable colour temperature. I have it in my house and it's indistinguishable from tungsten other than that the dimmable bulbs dim without changing colour temperature whereas a tungsten bulb becomes a warmer colour at lower brightnesses.

Unfortunately, almost no railway applications have selected quality LED solutions, they've cheaped out, and as a result the light quality is usually utterly horrible, be that a nasty blue colour temperature, excessive brightness, excessive glare or flicker.

Today, Yes, and for home use, Yes. However, bear in mind the time when the S-Stock was first specced out. I can tell you that in THOSE days, a decent LED lighting that behaved as a strip and was easy to replace/maintain/provide good light just might have not been available (I know as I myself was looking for some, and the only solutions were very pricey, and was not "stable"), AND had flaws in spread (not color quality, or flicker, of which even at the time, LEDs were already showing as superior)

And today, to replace the existing strips with equavelent LED may be possible, but requires a lot of work/time and therefore cost, somethign TfL may not have time to do, until they are re-furbed.

 

[Central]

Whilst having LED lighting is often desirable, its often a compromise. Remember traditional FL Tubes are still a lot more efficient than incandesent lights, with modern FL tubes and driving equipment reaching 80 to 100 lumens per watt (compared to 16 for incandesent, and 100 to 130 for LED white lights). The disadvantages of FL (apaprt from the energy) may be somewhat not applicable on train use:

• Warm Up time - since they are always on, not a real issue
• Disposal of hazardous waste - since railway companies have dedicated workshops, they are more likely to have proper facilities, and process at a reasonable cost
• lower lifetime than LEDs - balenced by being cheaper to replace tubes, and as stock is regularly maintained, the swapping canbe part of an ordidary schedule, and usually can be quicker than changing an LED

Also Tubes have one advantage over LEDS at the moment, the spread of ligh in all directions, LEDs can be still very directional, despite current advnaced in deflectors, and trying to defuse LEDS further impacts the lumens emmitted. Future research on Quantum Dots, as used on some TVs may prove fruitful. Tubes do however, provide a nice diffused and spread light by default, making it easier to fully illuminate a carraige. And this might actually be the real reason why the S-Stock still use FL?

I am sure the S-Stock has LED where a spot of light is needed, such as doorways, etc.

The bakerloo is being re-fitted with LEDs for probably other reasons, to avoid the issue of lights dimming at at power breaks (as LEDs are better buffered via a battery, or Super Capacitor)

Depots have tube crushers,glass ends up in box at the bottom,the powder inside is washed away.

 

[simple simon]

back in the old days the electronic control gear for FL lights produced a noticeable whine noise

This was a feature of the R stock