Lighting quality on trains: are you bothered?

[bramling]

That's a good point. The same carriage will have
People trying to work (laptop, documents)
People just chatting with friends
People watching movies on their phones/tablets
People reading
People relaxing and enjoying the scenery

All will have different lighting requirements.

Yet none of this seemed to be an issue 20 or so years ago. It only seems to have started becoming one when when the industry started messing around with different types of lamp.

 

[Bletchleyite]

Yet none of this seemed to be an issue 20 or so years ago. It only seems to have started becoming one when when the industry started messing around with different types of lamp.

I don't know, I used to hate the blaring Mk3 lighting, way overlit and poorly diffused. I used to go round switching them to dim (naughty naughty! ), the lighting controls were accessible to passengers back then, only later refurbs changed them to T-key locks.

 

[BRX]

The trouble is, that some of the railway companies market long distance trains as somewhere where a passenger can work. Hence they may think lighting should be suitable for working and reading.

How many offices have warm white lighting?

That's exactly what task lights, individually controlled above each seat are for. Somehow it's not beyond pretty much every long distance coach operator or airline to provide these.

 

[Bletchleyite]

No, LEDS in mains fittings (which the exception of very cheap or fake Chinese export ‘products’) flicker at 100Hz if smoothing capacitors are not used.

Must be cheap Chinese ones, then, because I can perceive 50Hz flicker very clearly (watching an old style CRT TV was a nightmare) but not easily 100Hz.

If you connect a diode directly to (transformed) 50Hz AC it will pulse at 50Hz, anyway, because a diode only allows current flow in one direction, which is what these cheap ones do. An incandescent bulb will pulse at 100Hz because it will light on both "sides" of the wave. You need a rectifier (a small network of diodes) to get the 100Hz by feeding the DC positive from both the "up" and "down" part of the AC wave (I forget the correct terms).

The trouble is, that some of the railway companies market long distance trains as somewhere where a passenger can work. Hence they may think lighting should be suitable for working and reading.

How many offices have warm white lighting?

Very few, but equally how many have daylight white lighting? Also very few, other than in Asia where it's the norm. It's normally cool white, as is kitchen lighting and other utility spaces.

 

[bramling]

Must be cheap Chinese ones, then, because I can perceive 50Hz flicker very clearly (watching an old style CRT TV was a nightmare) but not easily 100Hz.

If you connect a diode directly to (transformed) 50Hz AC it will pulse at 50Hz, anyway, because a diode only allows current flow in one direction, which is what these cheap ones do. An incandescent bulb will pulse at 100Hz because it will light on both "sides" of the wave. You need a rectifier (a small network of diodes) to get the 100Hz by feeding the DC positive from both the "up" and "down" part of the AC wave (I forget the correct terms).



Very few, but equally how many have daylight white lighting? Also very few, other than in Asia where it's the norm. It's normally cool white, as is kitchen lighting and other utility spaces.

We’ve only ended up with cool white lighting in offices by default, as a result of the advent of fluorescent lighting, which at the time was much cheaper to run than what came before.

My office still has this, but I don’t use it. During daylight I simply have all the lights off with just a desk lamp as a task light. During darkness hours I simply put several desk lamps on in strategic parts of the room. All of these have tungsten-replicating LEDs.

 

[Pigeon]

Must be cheap Chinese ones, then, because I can perceive 50Hz flicker very clearly (watching an old style CRT TV was a nightmare) but not easily 100Hz.

If you connect a diode directly to (transformed) 50Hz AC it will pulse at 50Hz, anyway, because a diode only allows current flow in one direction, which is what these cheap ones do. An incandescent bulb will pulse at 100Hz because it will light on both "sides" of the wave. You need a rectifier (a small network of diodes) to get the 100Hz by feeding the DC positive from both the "up" and "down" part of the AC wave (I forget the correct terms).

You need a full-wave rectifier to feed your DC load on both positive and negative half-cycles. A single diode on its own acts as a half-wave rectifier and only feeds you one of them.

LED bulbs have one. Although an LED is indeed a diode, you can't use it as its own rectifier because it is very bad at withstanding reverse voltage, so you need to precede the LEDs with a separate rectifier made from "proper" diodes. These rectifiers are always full-wave types, for several reasons, one of which is indeed to get a ripple frequency of 100Hz rather than 50Hz so it's easier to filter out.

An LED is a current-driven device, so to run it off a voltage source you also need some means of limiting the current it can take, without wasting power in the process. The simplest and most potentially robust method of doing this is to insert a series capacitor on the AC side of the rectifier as a reactive ballast; with the output from the rectifier thus limited, you can safely connect it directly to the LED string without further ado, although to do a proper job you also need a reservoir capacitor on the DC side to filter out the 100Hz ripple.

Unfortunately when the Chinese do this they do not do a proper job; they use a reservoir capacitor with only about a tenth as much capacitance as is actually needed, so its filtering effect is essentially zilch and the LEDs still flash on and off 100 times a second, usually spending about as much time off as on. They also use a ballast capacitor which, while it does have the correct capacitance, is grossly underrated for the amount of power that is being put through it, so it doesn't take long to cook itself and stop working. (Neither of these problems are inherent to this design; they don't manifest at all when I use it because I do actually bother to select the components correctly.)

This method lacks versatility, and it is not appropriate for bulbs which use a small number of high-current LEDs, as many do, instead of a large number of small ones. So less basic bulbs use some form of switching regulator as a ballast. These operate at a frequency of several kHz at the very minimum, so the output ripple needs only a small capacitance to filter it out and is in any case far too fast for the eye to perceive.

However there is still a need for a reservoir capacitor to reduce the 100Hz ripple at the input to the switching regulator, otherwise it still has 100 gaps per second in its ability to obtain current, so the method is still vulnerable to flicker resulting from not making the input reservoir capacitor big enough. Or indeed from missing it out altogether. Some of the switching regulator ICs sold for LED light bulbs claim that they regulate so well that they can keep the LEDs alight even during the periods where the input falls to zero, and therefore you don't need an input reservoir capacitor. This claim basically isn't true, and if you leave it out they will still flicker, you just have the ready-made excuse that the IC manufacturer said things that weren't true miss.

 

[Annetts key]

The above describes two types. But there are also other types. Each with different performance characteristics.

Types that ditch the series capacitor and also the smoothing capacitor, and instead use a long series chain of LEDs, or a series chain of multi-chip LEDs (typically 5 or 6 LEDs in the same package) and a current regulator chip or chips do suffer from 100Hz flicker. But because the on time is relatively short during the mains waveform, it’s actually a lot worse and the effect is nearer towards what you would get at a lower frequency.

One problem is that there is no requirement or standard to inform customers what type of technology is being used. So until you buy it and try it, you won’t know how well it will perform.

 

[stuu]

Yet none of this seemed to be an issue 20 or so years ago. It only seems to have started becoming one when when the industry started messing around with different types of lamp.

Perhaps there were just less routes to moan about it?

 

[Pigeon]

The above describes two types. But there are also other types. Each with different performance characteristics.

Types that ditch the series capacitor and also the smoothing capacitor, and instead use a long series chain of LEDs, or a series chain of multi-chip LEDs (typically 5 or 6 LEDs in the same package) and a current regulator chip or chips do suffer from 100Hz flicker. But because the on time is relatively short during the mains waveform, it's actually a lot worse and the effect is nearer towards what you would get at a lower frequency.

The ones with linear current-source chips, resistive in action, paralleled up to achieve the desired total current? I'm not sure those gruesome abortions are suitable for discussion on a family forum. I know my opinions of them aren't. The only thing they're good for by my reckoning is to strip and extract the series LED chain assembly to use as the basis for something better.

One problem is that there is no requirement or standard to inform customers what type of technology is being used. So until you buy it and try it, you won't know how well it will perform.

Yep. This is another reason I make my own

And the information you do get is not reliable; a good half of the listings I've seen selling the abovementioned abortions claim they produce no flicker. Often alongside a photo of the thing which is clear enough that you can trace the circuit, read the type numbers on the chips, google the datasheet, and immediately see that that can't possibly be the case.

 

[Annetts key]

We appear to have rather drifted off topic, back on topic, what do people make of the lighting on GWR Turbos?

 

[BRX]

Travelling today and have just switched from a refurbed Avanti pendolino to a Scotrail HST. The difference is stark.

On the pendolino they've got it exactly right, I'd say. Comfortable brightness & temperature for the general lighting, with task lights above seats. It creates the ambiance you want on an intercity train.

On Scotrail of course it's a complete disaster. As per comments earlier in the thread. I've done quite a few journeys on Scotrail HSTs recently and the lighting hasn't bothered me too much: because they've been done on bright sunny days, of which there have recently been more than usual, in Scotland. When the light outside is so bright, it's not the internal lighting that dominates.

Today though, it's back to grey evening skies and the awful lighting is all too obvious again. In fact they actually manage to look the grey day outside look warmer than the interior of the carriage. I think this might partly down to the tint that's on the windows. But in any case, the result is a terrible one, for a train that's supposed to provide a relaxing intercity type ambience in a northerly country with an abundance of cloudy skies. Note in the distance the lighting in the vestibule/corridor around the (unused) buffet area, where the colour temperature is ok. It was just too much effort to do anything about the parts where passengers sit.

 

[Mat17]

Never thought about lighting. It's not something I notice, I've even been in a few trains where I didn't even realise the lights weren't on until we went through a tunnel.

 

[Annetts key]

On Scotrail of course it's a complete disaster. As per comments earlier in the thread. I've done quite a few journeys on Scotrail HSTs recently and the lighting hasn't bothered me too much: because they've been done on bright sunny days, of which there have recently been more than usual, in Scotland. When the light outside is so bright, it's not the internal lighting that dominates.

Today though, it's back to grey evening skies and the awful lighting is all too obvious again. In fact they actually manage to look the grey day outside look warmer than the interior of the carriage. I think this might partly down to the tint that's on the windows. But in any case, the result is a terrible one, for a train that's supposed to provide a relaxing intercity type ambience in a northerly country with an abundance of cloudy skies. Note in the distance the lighting in the vestibule/corridor around the (unused) buffet area, where the colour temperature is ok. It was just too much effort to do anything about the parts where passengers sit.

That’s the norm for refitted HST MK3 coaches, The GWR Castle Class is the same. It does not bother me.
The GWR IET/80X have lighting that is just as bright and a similar white colour temperature.
As does the lighting in most Network Rail offices…

 

[BRX]

It's the "norm" for the ex mainline GWR mk3s which is what the Scotrail ones also are. Other TOCs managed to refit HST mk3s without such horrible results. It's a shame Scotrail didn't inherit LNER ones instead.

 

[BRX]

This weekend I did my first couple of trips on the London-Norwich trains since the mk3s were replaced.

The lighting on the new trains is much too bright. The colour temperature is not as bad as scotrail HSTs but is a little on the cold side. But it's too bright and there's no use of indirect lighting. So the lighting strips are directly visible all of the time. This doesn't provide for a relaxing environment at all and it certainly doesn't create anything like an "intercity" ambience. So this route is no longer recognisable as an intercity one and feels like a London commuter service.

Just a week previously I travelled on a German ICE. The lighting and atmosphere is so different and so much better, like night & day. They feel like proper long distance trains where you can settle into a relaxed frame of mind for an extended time - nothing to encourage that on the Greater Anglia services. It's a shame because just turning down the brightness would make a big difference.

 

[Bletchleyite]

Went on a 196 on Sunday. I thought the lighting was absolutely bob-on - a relatively subdued, indirect set of main lights plus spots down the aisle, almost identical to the TfW 158 I had just got off. (The latter was packed, the former was empty, so I considered a bit more space worth half an hour).

I think 397s have the same setup. The spots really do add a touch of class.

 

[whoosh]

If you compare UK train lighting to road coach lighting, or airliner lighting, then UK train lighting is usually way too harsh or adjustments are non-existent. In most cases in other words, "lacking" in comparison.

 

[Bletchleyite]

If you compare UK train lighting to road coach lighting, or airliner lighting, then UK train lighting is usually way too harsh or adjustments are non-existent. In most cases in other words, "lacking" in comparison.

Road coach lighting isn't really comparable as people don't move around road coaches like they do trains, plus it has to be subdued a bit so as not to distract the driver too much.

 

[whoosh]

Road coach lighting isn't really comparable as people don't move around road coaches like they do trains, plus it has to be subdued a bit so as not to distract the driver too much.

Whilst what you say is true, it's a lot more - shall we say, "mellow." "Relaxing" even. "Superior" it could be argued?! Would you say?

 

[DarloRich]

I want it bright ( might be age!) but I don't care enough to make an issue of it. I found the old Pendo lighting dingy but many here loved it. I prefer the new one.

 

[Class 170101]

Without wading through this thread, isn't the brightness of the lighting also determined by the law? eg the Equality Act?

 

[Mzzzs]

I love the 345 lightings however I would like them to turn up the brightness just a little

 

[Bletchleyite]

Without wading through this thread, isn't the brightness of the lighting also determined by the law? eg the Equality Act?

There is that aspect, but as the quality and brightness varies from new unit to new unit, and presumably all new units either comply or succeeded in obtaining a derogation, then I think we can conclude it doesn't have to be stark like some are.

Another quite classy one is the 345. Generally indirect is best.

 

[BRX]

Without wading through this thread, isn't the brightness of the lighting also determined by the law? eg the Equality Act?

It seems that it is, but that it doesn't determine that it needs to be anything like as bright as is implemented in many new trains, and what we get is actually determined by how much effort/resource is put into the design.

 

[Bletchleyite]

I love the 345 lightings however I would like them to turn up the brightness just a little

I love it as it is. The 720s are the same - awful seating but the rest of the package is near-perfect for a regional express/commuter EMU. The newer London Overground units have it the same and I quite like it there too, it looks classy, compared to the older LO units which look dingy and a bit unsafe.

I seem to recall it's adaptive based on the external conditions.

 

[physics34]

U dont matter anymore as the passenger.LEDs are cheaper, that takes presedence. The fact that weve had 'warm white' lighting for many decades doesnt matter to them. Now its bright white or nothing. Same situation is happening with car headlights and streetlights

 

[PacerTrain142]

Yes I don't like it when its too bright at night because you can't see alt out of the windows. And yes I prefer warmer colour temperature lights. The bright white hospital - style lighting on class 150's and class 195's means you can't see a thing on a night journey. I preferred the dimming lighting on the pacers. But to be honest it's such a small niggle it's hardly worth discussing, there's much bigger things to worry about right now - strikes, rail fares, cost of living etc.

== Doublepost prevention - post automatically merged: 22 Aug 2023 ==

A nice warm tungsten glow is the best - as on the thumper.

That looks so nice and cosy. Why can't train carriages be like that now?

 

[Jonny]

The opposite issue arises on Bakerloo line trains, particularly on Network Rail tracks (past Queens Park) where the lights are prone to going out and coming on again suddenly. It was a few months since I was last there, but it was a major issue.

 

[physics34]

The opposite issue arises on Bakerloo line trains, particularly on Network Rail tracks (past Queens Park) where the lights are prone to going out and coming on again suddenly. It was a few months since I was last there, but it was a major issue.

Loads of 'gaps'

 

[BRX]

But to be honest it's such a small niggle it's hardly worth discussing, there's much bigger things to worry about right now

I don't think it's just a "small niggle". Stuff like this, added up with various other things to do with passenger environment (like, say, stations with nowhere warm to wait), has an impact on how people perceive rail travel and make journey choices, and result in other modes of transport being chosen.

It's not something that in most cases would be horrendously expensive to improve - it just needs some people at TOCs (or whoever is specifying train interiors) taking it seriously.

As is mentioned up the thread, long distance coach operators, airlines, *some* railway operators in the UK and elsewhere in Europe, manage to get it right. The point about coach/air companies is important because they are the competition. Rail ought to be one of the most comfortable modes of transport - it has loads of advantages built in that can make it more comfortable - why throw this advantage away by failing to pay attention to lighting?

Services overseen by TfL generally seem to be OK - and probably reflects the relative amount of resource they put into passenger environment. They generally know what they are doing, but many TOCs just don't seem to know what they are doing.

It was rather disappointing to travel on the Greater Anglia 745s and find they have messed up on the lighting. There are lots of other things to like about these trains, but the ambience simply is not one of an intercity train. Somehow, they managed to approve whatever mock-ups were made of the interiors, without anyone questioning the lighting. They don't have the (weak) excuse that Scotrail has for its HSTs, which it inherited as is and can claim that modifying the lighting is too expensive or difficult. These are brand new trains. On their own website they describe the 745s as "very spacious and a high quality, sumptuous feel to the carriage". Not after dark - it doesn't feel sumptuous and high quality, it feels like a harsh and overbright environment, one that might be ok for an urban metro service for short journeys but not for jpurneys approaching 2 hours in length. Am considering making sunglasses part of my standard travel kit.