Internal lighting of heritage coaches

broadgage · 15 Jul 2014

As is fairly well known, the saloon lighting in traditional loco hauled coaches is often self contained.
A battery under each coach is charged by a dynamo, this being belt driven from an axle. This system has the merits of operational simplicity since any coach so equipped may be hauled by any loco.

The equipment is however rather complex, it needs to produce DC of the same polarity despite changes of direction, the battery charging voltage needs to be regulated, and the voltage on the lamps also needs regulating.

With the low speeds and frequent stops on a heritage railway the batteries tend to become discharged and the lamps very dim. In an attempt to limit battery discharge, many heritage railways remove half the lamps and/or use lamps of lower power than was originally intended.

The lamps are usually 24/25 volt, often 15 or 25 watt. These lamps give a poor light since they are designed for least cost and long life, not efficiency.

I would therefore suggest that heritage railways give consideration to replacing these lamps with LEDs.
LED lamps are available that use 2 or 3 watts and give a similar light to 15 or 25 watt incandescent lamps.
The light output is constant over a range of 10 volts to 30 volts, no dimming or flickering with changes in speed.
The much reduced load will greatly increase the battery life, and may permit of a few more years service from batteries otherwise considered life expired.

Anyone here who volunteers as an electrician on a preserved line ?

Although this is a RAILWAY forum, these new LED lamps are also worth considering for vintage buses, yachts, caravans etc.

I have no connection with any vendor of these lamps.

RailUK Forums

paul1609 · 15 Jul 2014

I know that the Spa Valley Railway have been using LEDs for sometime. at the K&ESR we are currently trialling another automotive LED.

gazthomas · 18 Jul 2014

I agree with this recommendation. Any benefit of using solar panels too?

fireftrm · 18 Jul 2014

NYMR are also fitting LED lighting as and when possible and when refurbishing coaching stock

Nym · 18 Jul 2014

There are some very nice Festoon lamps that I have used for a smaller locomotive when building components. They'll run off 6V, 12V or 24V, I believe they're happy at 110V too.

Blindtraveler · 18 Jul 2014

whats the most modern coach design with this type of equipment?

Tracky · 18 Jul 2014

I'm interested to see this. I suggested my local heritage line develop some low voltage LED based lighting system which they could then flog to all the other heritage lines for a small but worthwhile profit. Alas, it didn't happen.

fireftrm · 18 Jul 2014

Don't think it would have made any money anyway, the people working on heritage equipment are extremely resourceful and without much money. Fitting LEDs into authentic and original light fittings is no problem for them, they would never consider spending their very valued funds on something they could do themselves.
If the HRA made them available, from whichever railway converted/produced light fittings, at the near cost price perhaps they would be valued, but the originating railway would probably struggle to produce a reason to do this!

SpacePhoenix · 19 Jul 2014

If they're using fluorescent tube type lights then there's already LED versions available. There seems to be LED versions of many types of bulb now, it might be a problem though if they're using an unusual/non standard size and/or rating

broadgage · 26 Jul 2014

gazthomas said:
I agree with this recommendation. Any benefit of using solar panels too?

The energy from a solar panel of reasonable size would be limited if compared to that available from the belt driven dynamo and at first sight there would seem little benefit in fitting solar panels.

However lead acid batteries are liable to premature failure if left standing in a discharged state.
For coaches in infrequent use, the fitting of a couple of PV modules and a charge controller would slowly charge the batteries and probably greatly prolong the working life.
A few hundred watts of PV would charge a 24 volt nominal battery at a few amps (nothing like the nominal output will be achieved due to the non optimum mounting angle etc)
That would fully charge the battery in a week or so and keep it in good condition.
No significant use of the internal lights would be possible without discharging the battery faster than the PV can charge it. A brief weekly inspection with the lights turned on should be OK though.

PV modules could also be used to keep the batteries of seldom used DMUs in good condition and always ready for instant use.

In theory diesel loco starter batteries could also be trickle charged from PV modules, but in practice I doubt that most locos have sufficient unobstructed roof space for installation of the modules.

bronzeonion · 26 Jul 2014

I'm a carriage & wagon fitter (as well as a few other things) at the Epping Ongar Railway and to put it simply, rather than relying on the old dynamo style method we have fitted a generator to the underneath of a carriage which provides electricity for the carriage lighting. This can provide lighting for the whole train through new jumper cables we have installed on the ends of the carriages.

fireftrm · 28 Jul 2014

We externally charge our batteries, using the standard BR lighting socket. We have considered using generators, however only do so for certain stock as a power source for cooking, then under very strict conditions. The fire risk of an engine, not designed for the rail carriage, is too great.

Wikipedia · 28 Jul 2014

I have heard that you can get a regulator unit which over fields the dynamo so that you get full output at a much lower speed than normal making them more suited to heritage operations.
No idea how much one costs mind.

bronzeonion · 28 Jul 2014

fireftrm said:
We externally charge our batteries, using the standard BR lighting socket. We have considered using generators, however only do so for certain stock as a power source for cooking, then under very strict conditions. The fire risk of an engine, not designed for the rail carriage, is too great.

We externally charge them too whilst stabled in the platform where we can plug them in, though not through the lighting socket we plug ours into where the generator would normally be plugged into.
--- old post above --- --- new post below ---

Wikipedia said:
I have heard that you can get a regulator unit which over fields the dynamo so that you get full output at a much lower speed than normal making them more suited to heritage operations.
No idea how much one costs mind.

That would be ideal as with the generator running with the train at a stand, after a while the brake does get quite fumy!
With the dynamos not kicking in till 20mph or so, me and few others have always thought you could change the actual wheel on the dynamo unit for a smaller one, maybe half the size which would mean juice starts flowing at half the speed required with a conventional sized wheel. Have heard this wouldn't work before though.

broadgage · 29 Jul 2014

It would be possible to increase the output of a standard dynamo at low rail speeds by changing the ratio of the belt drive such that at a given rail speed the dynamo is driven twice as fast.

This would not be suitable for main line passed stock because the dynamo would be over speeded at main line rail speeds.
Fine for heritage only use though.

Another option would be a standard modern alternator as fitted to a truck or bus, belt driven from a coach axle.
Such alternators are relatively cheap due to mass production, have a wide speed range, and are durable. They are already equipped with a suitable regulator for battery charging.
The voltage available for lighting etc. would vary a bit from about 23/24 volts when the battery was discharging, up to about 27/28 volts when charging.
This is tolerated on road vehicles, but with filament lamps might be objectionable on a railway coach.
If however LED lamps were used that give a constant light at varying voltage, then it would be fine.

Daniel Pyke · 29 Jul 2014

There are a multitude of LED lighting modules available now, just make sure that you pick the "warm white" ones (the cool white ones are rather blue tinged), to get the authentic feel of incandescent light.

Whilst solar cells on the roof may be a good solution to keep seldom used stocks batteries topped up, they are too small a capacity for a general charging solution.

Waldgrun · 29 Jul 2014

I understand that Metropolitan Railway Jubilee Coach 353, was fitted with LED lighting when restored, to recreate the effect of gas lighting, as this vehicle was used during the Underground 150 events, and gas not being thought safe for coach lighting is this day and age! However, I can not find any pictures of this light on the web, does anyone know of any?

broadgage · 29 Jul 2014

Daniel Pyke said:
There are a multitude of LED lighting modules available now, just make sure that you pick the "warm white" ones (the cool white ones are rather blue tinged), to get the authentic feel of incandescent light.

Whilst solar cells on the roof may be a good solution to keep seldom used stocks batteries topped up, they are too small a capacity for a general charging solution.

Yes, agree entirely with both points.

bluegoblin7 · 29 Jul 2014

Waldgrun said:
I understand that Metropolitan Railway Jubilee Coach 353, was fitted with LED lighting when restored, to recreate the effect of gas lighting, as this vehicle was used during the Underground 150 events, and gas not being thought safe for coach lighting is this day and age! However, I can not find any pictures of this light on the web, does anyone know of any?

The coach is running on Saturday as part of the Steam on the Hammersmith & City celebrations. I'll try and get a photo for you during the layover at Hammersmith.

Waldgrun · 30 Jul 2014

bluegoblin7 said:
The coach is running on Saturday as part of the Steam on the Hammersmith & City celebrations. I'll try and get a photo for you during the layover at Hammersmith.

Thank you, I look forward to seeing your efforts!

fireftrm · 1 Aug 2014

broadgage said:
It would be possible to increase the output of a standard dynamo at low rail speeds by changing the ratio of the belt drive such that at a given rail speed the dynamo is driven twice as fast.

Also done by our C&W staff, changing the diameter of the pulley on the dynamo. The external charging is either by the lighting input socket (on some carriages), or to the batteries via the dynamo regulator box - answering bronzeonion.

apk55 · 2 Aug 2014

The traditional fillement lamps are not a very efficient light source compared to LEDs. The ones used on railway service should be "rough sevice" type where the filament is well suported to withstand vibration and they are often underrun with lower filament temperature which futher reduces efficencey. They are now probably quite expensive to obtain as they are a specialist item.

LEDs are probably more than 10 times more efficient than traditional fillament lights so not only are the charging requirments reduced but a battery would last much longer. On many preserved lines where speeds are low and stops long the traditional system probably hardly works.

There is no problem in getting LEDs (try EBAY) although most are designed to run off 12V. There is a lage varity of types available, from PCBs with may LEDs stuck on them, flexible strip strung along it and MR16 style floodlights.

(However you can get quite cheaply some voltage converters that will drop 24V to 12V - they are intended for use in trucks and coaches so should quite robust).

I have several 4W MR16 lamps in my house and they give more light than the 20W Halogen lights they replaced.

broadgage · 3 Aug 2014

Filament lamps in general do indeed have a very poor efficiency, and those used on railways are even worse, since as posted above they are optimised for long life not for efficiency.

If a filament lamp is run at less than the proper voltage then the already poor efficiency is further reduced.
I suspect that many of the lamps used for saloon lighting are badly under run. If the equipment is working correctly, the lamp voltage is regulated at 24/25 volts despite the battery voltage varying.
The lamps often used are "bus bulbs" and despite being marked "24 volt" are in fact designed for about 28 volts, that being the actual voltage available when the engine of a bus is running and the battery is on float charge.

Use of 28 volt lamps on 24 volts will further reduce the already poor efficiency.

Use of true 25 volt filament lamps produces a noticeable improvement, as compared to bus bulbs intended for 28 volts.

LEDs would of be better still, and are undoubtedly the way forward.

Both true 25 volt lamps and "bus bulbs" intended for 28 volts are still fairly readily available, but I do wonder for how much longer.

Where relatively high power 25 volt lamps are needed, such as for lighting guards vans, mail coaches, or mobile workshops, then currently available LED lamps may not be bright enough.
24 volt CFLs may be worth considering for such places, they are far from common but can be found on fleabay.

D2022 · 12 Aug 2014

I know it's a little off topic but I restore vintage bicycles in my spare time and have had some great success with LED cluster lamps in place of the normal bulbs. BUT they look different, the colour is different, I wonder would that matter in a pres coach?

Daniel Pyke · 13 Aug 2014

D2022 said:
I know it's a little off topic but I restore vintage bicycles in my spare time and have had some great success with LED cluster lamps in place of the normal bulbs. BUT they look different, the colour is different, I wonder would that matter in a pres coach?

As I said earlier, standard white LED's are very "blue". If you use warm white LED's then they have a much whiter colour. You could always swap a couple of the LED's for yellow ones if you wanted to give the old incandescent look.

Generally white is rated by colour temperature

•Warm White 2700K
•White 3500K
•Cool White 4500K
•Daylight 5500K
•Cool Daylight 6500K

D2022 · 13 Aug 2014

Daniel Pyke:1883320 said:
D2022 said:

I know it's a little off topic but I restore vintage bicycles in my spare time and have had some great success with LED cluster lamps in place of the normal bulbs. BUT they look different, the colour is different, I wonder would that matter in a pres coach?

Click to expand...

As I said earlier, standard white LED's are very "blue". If you use warm white LED's then they have a much whiter colour. You could always swap a couple of the LED's for yellow ones if you wanted to give the old incandescent look.

Generally white is rated by colour temperature

•Warm White 2700K
•White 3500K
•Cool White 4500K
•Daylight 5500K
•Cool Daylight 6500K

top man!! I will have a look for some

broadgage · 20 Apr 2015

On a couple of recent trips on the West Somerset railway, I was pleased to observe that a number of coaches had been equipped with 3 watt LED retrofit lamps.
These are a drop in replacement for the previously used incandescent bulbs and seemed to give a brighter light.
These lamps give a constant light output at any voltage between 10 volts and 30 volts, and should therefore be immune to the variations in brightness often observed with filament bulbs.

Some time ago I suggested to the WSR that these lamps be used, I don't know if they installed them as a result of my recommendation or if this was already in hand.

sparkman · 30 Jul 2015

I have located a source of golf ball lamps which are an exact replacement for the incandescent golf ball lamps used in BR Mark 1 coaches. They are £8 each but the supplier requires a minimum order quantity of 500 lamps. We can use about 200 on the Epping and Ongar Railway. Is there any interest in these LED lamps from other heritage railways?

theageofthetra · 1 Aug 2015

The only thing to be carefull about is not to destroy the atmosphere of the old lighting. For a good example look at the difference between the two Hastings Diesel motor coaches on the clips on another thread. Totally understand the benefits of using modern LED technology but if its all about efficiency then heritage traction wouldn't exist.

455driver · 1 Aug 2015

Do they give off the same sort of light as an incandescent bulb, a lot of LED bulbs give off a harsh white light.

Internal lighting of heritage coaches

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