158s, 159s, 166s and 442s were fitted with not entirely reliable air conditioning prior to privatisation.In the UK air conditioned trains have been around for decades, but only became common in non-InterCity stock after privatisation.
Trains making frequent station calls with associated doors opening and closing meant the benefit of air-con was quickly lost.
Arguably on outer-suburban trains opening windows are better than air-con. A ride at 100mph on the ECML in a much missed class 365 on a hot summers day with the windows open was rather good![]()

To be fair, it's not always the fault of the AC unit's reliability itself. Some of the older units were designed to run on now-banned CFCs, for which the replacement gases are more prone to leaking and often simply aren't as effective as refrigerants (but they also don't destroy the ozone layer, so the trade-off is definitely worth it!)It’s curious the 365s didn’t get A/C from new considering stuff like the 158s and 166s did, though for that we should be thankful as most 1990s A/C proved very unreliable.
Adtranz (as it then was) actually produced a prototype of something called the Turbostar Traveller, which was missing aircon and various other features such as overhead racks. It was exhibited at one of the trade shows in the NEC but eventually re-made and sold as one car of a standard 170.It seems possible that had a derivative of the 170 been largely aimed at local services it may have had opening windows. 376s didn't get air conditioning because it was felt that it wouldn't work with the frequent door opening cycles. As we know, this was disproved with the 378s.
A couple of factors I wonder about but these are only guesses:Trains making frequent station calls with associated doors opening and closing meant the benefit of air-con was quickly lost.
Arguably on outer-suburban trains opening windows are better than air-con. A ride at 100mph on the ECML in a much missed class 365 on a hot summers day with the windows open was rather good![]()
There's also the issue that many crews aren't trained on how to shut them down properly, as discussed in various other topics. The Electrostar/Turbostar (and I think the Desiro too) units have all the mechanics within a single package that can be lifted out and replaced as a unit.To be fair, it's not always the fault of the AC unit's reliability itself. Some of the older units were designed to run on now-banned CFCs, for which the replacement gases are more prone to leaking and often simply aren't as effective as refrigerants (but they also don't destroy the ozone layer, so the trade-off is definitely worth it!)
I find the late 90s era units on the earliest electrostars/turbostars absolutely fine. Heck on Southern my complaint is often that they have it too cold, I shouldn't need to wear a jumper when it's nearly 30°C outside!
I'm not so sure that the root answer to this question should focus on UK trains so much as UK attitude to A/C. Basically, every decade or so we become richer and our standards increase. The improvements to rail are just a foreshadowing.
This is an interesting take and may well be a good answer to the original question. However does it mean that, as we now seem to be getting poorer as a country in managed decline, that we might just see non air-conditioned trains again within a generation?!
I travelled regularly on 313s and 455s this summer. If you think non-Intercity trains don't need AC you are sorely mistaken!I don't think air conditioning is necessary on non-Intercity stock in this country, and especially not on commuter stock (for example, the 323 units in my area) and would personally prefer some kind of opening window system for these. Maybe I'm behind the times, but for sure being stuck on a train with non-functioning air conditioning and windows which don't open is the worst of all worlds, 158s for example. Yes, opening windows can cause problems of their own but in warmer weather they're effective in creating a flow of (warm) air which is usually tolerable on a stopping local service.
Not mentioned so far is the huge advantage of air-conditioning in winter. The "conditioning" factor is not just about temperature control but also about humidity. A/C in winter can significantly improve the travel environment by dehumidifying all that dampness brought onto trains by its passengers during wet weather. It also reduces damp related deterioration of seating and onboard equipment. Well worth it.
AbsolutelyI travelled regularly on 313s and 455s this summer. If you think non-Intercity trains don't need AC you are sorely mistaken!
I find the Networkers in winter have that sort of smell as well!Indeed so. People often say "buses smell of wee". They don't, but what they do smell of is damp and mould, because in winter they never really dry out properly. A combination of double glazing and aircon solves that completely.
Not just in winter!I find the Networkers in winter have that sort of smell as well!
I'm not so sure that the root answer to this question should focus on UK trains so much as UK attitude to A/C. Basically, every decade or so we become richer and our standards increase. The improvements to rail are just a foreshadowing.
In other words - you could ask the same about our houses, never mind trains. I think it's under 2% of housing in the UK that has air con. Speaking for my wife and I, we still have a couple of portable air conditioning units from when we lived in a 1 bed flat in the South East; once we were in a position to buy a house then had it had been down there then we'd undoubtedly have shelled out on a proper air con install. Up here it's not hot enough to need it when we have the units; during last summer's heat wave running them along with keeping curtains and windows shut was enough to keep a 3 bed pleasant.
But most people are unfortunate enough to live in the South East and with global warming and increased insulation efficiency, as well as increasing work from home and a fattening population I expect air conditioning to become much more popular residentially.
Try travelling on an pre-Privatisation train fitted with air conditioning in 25 degree and more weather - It's not a nice experience due to their unreliability, ineffectiveness and lack of maintenance; I've been on many toasty MK3s and 158s.I travelled regularly on 313s and 455s this summer. If you think non-Intercity trains don't need AC you are sorely mistaken!
Roughly about the same time as BR were rolling out knackered old 455s relying on openable windows, NSW CityRail (now Sydney Trains) introduced these Tangaras, which have rather strong air-conditioning. Tbh, it’s needed far more over here than it was in England, but considering both are from the 80s these look and feel far more modern, especially externally.
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Photo shows an 80s Sydney Trains T Set “Tangara” at Cronulla, in silver and yellow colours. The day is sunny with a few clouds and the platform is long and sloping.
Indeed so. People often say "buses smell of wee". They don't, but what they do smell of is damp and mould, because in winter they never really dry out properly. A combination of double glazing and aircon solves that completely.
When 158s first entered service in the west of England we were trained how to reset the air conditioning should it fail. Later in their life the cupboard locks were changed and guards were told not to interfere with them no matter how hot/cold the unit was. The EBAC system is far better than the Temperature ones and were easier to reset.There's also the issue that many crews aren't trained on how to shut them down
A lot of this could be solved with the combination of heating and fresh air, though. Something like a 365 never had this issue as you’d have the heating running, including when stabled.
My older BMW gets the occasional musty smell when it sits still for a while now it doesn’t see as much use as in past times, however just starting it up and taking it for a relatively short drive with the heating running is more than enough to address the issue, so it’s only an issue when something arises which prevents the occasional outing. I’d presume the bigger issue with buses is that they sit cold all night.
Houses have walls mainly made of brick or concrete, and small windows that can be covered with curtains, so the direct rays can be blocked out. By contrast, cars have lots of glass which has to stay uncovered so that you can see out!Not wanting to go off topic too far, however the user of cooling in homes is likely to increase over time, although with most new builds looking like their going to have air source heat pumps as standard in the not too distant future I could imagine running them backwards to cool a house could become standard in time.
A full AC system in a home is often overkill for most given the limited use that it would otherwise have.
AC in cars is more useful than a home at they often get hot parked and the benefits of removing moisture also makes it useful for more of the time. Likewise with climate control seeing it to a temperature, it means that longer journeys are more pleasant and require a lot less adjustment to the fans hot/cold dials.
As for trains, BR would have had budget constraints and so would have been careful about what they spend whilst after privatisation there was a desire for improvements to rolling stock and so AC was an easy win.
Adtranz (as it then was) actually produced a prototype of something called the Turbostar Traveller, which was missing aircon and various other features such as overhead racks. It was exhibited at one of the trade shows in the NEC but eventually re-made and sold as one car of a standard 170.
Not that I'm aware - I saw it at said trade show. I think Modern Railways had a piece on it - would be 1996 or 1997 I think.That's interesting, any information of photos available anywhere?
The original AC on a Comeng had a tendency to fail above 34 degrees. After the high profile failures during Feb 2009 they did replace them.Comeng trains were introduced in Melbourne in 1981 and were fitted with airconditioning. The picture below shows them in their current livery.
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