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High levels of pollution onboard diesel trains

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Emblematic

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From a BBC News magazine article posted today:
But my biggest surprise was on my train journey. Diesel-powered trains like the one I commute on are found on many major routes across the UK. The East Coast Main Line north of Edinburgh, the Great Western route through to Cornwall, and London services to Sheffield and Nottingham are just some examples.
The average reading I got on-board my air conditioned train was 8.5. A researcher from King's College conducted an experiment to mirror mine on his train journey from London to Exeter and came out with similar results.
My time spent standing on the station concourse at London St Pancras, waiting for my train, produced a reading of 13.2.
So it turns out that during the 80 minutes I spend sitting still on a train every day I am being exposed to more diesel fumes than when I'm walking or cycling down a street full of traffic in London. On the day I took an electric train instead, my reading was only 2.4.
it does seem that diesel is getting an increasingly bad press.
 
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BestWestern

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Our society is packed with toxic filth. Fumes from traffic, fumes from industry, acid rain, rats and mice infesting every corner of our towns and cities, heaven knows what in the water supplies, chemicals galore in much of the food we consume... And diesel trains create diesel fumes too. It's the world we live in, and I'd suggest that for most hard pressed commuters it probably isn't high on their list of daily stresses! Just a slow news day and a journalist trying to be relevant and serious. Non-news.
 

CosherB

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Our society is packed with toxic filth. Fumes from traffic, fumes from industry, acid rain, rats and mice infesting every corner of our towns and cities, heaven knows what in the water supplies, chemicals galore in much of the food we consume... And diesel trains create diesel fumes too. It's the world we live in, and I'd suggest that for most hard pressed commuters it probably isn't high on their list of daily stresses! Just a slow news day and a journalist trying to be relevant and serious. Non-news.

Like what exactly?
 

kieron

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Stresses? Pollution kills people.

Personally, I'd prefer it if diesel trains were designed in such a way that it was normal to turn the main engines off when they're stationary.
 

BestWestern

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Like what exactly?

Oh come on, there's all sorts of stuff in there I'm sure! If you drink the tap water in London (or any other major city) do you really think it's pure and fresh and clean?! :D

Personally, I'd prefer it if diesel trains were designed in such a way that it was normal to turn the main engines off when they're stationary.

I agree entirely. Operators of older DMUs, in particular, must not only cause significant tonnages of needless pollutants, but also waste an enormous volume of fuel (and money) having seemingly no requirement for the engines to be shut down during layovers. If the reliability of the batteries or other components is that poor then get your engineering bods to sort it out!
 
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OneOffDave

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Oh come on, there's all sorts of stuff in there I'm sure! If you drink the tap water in London (or any other major city) do you really think it's pure and fresh and clean?! :D

Drinking water has really strict limits on what it can contain and is frequently tested. Where it's found to exceed these limits action to correct is taken and consumers are warned about using the water and often provided with alternative water supplies. Details about permissible levels of substances and micro-organisms can be found here
 

kevin5025

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The article is really interesting to read in detail. Some of the findings were logical - sitting in the house got a low reading - while sitting in a black cab in traffic got the highest reading. But, the rail results were surprising, and not in a good way. The reading was 1.7 for walking around town, 2.1 for driving, 3.7 cycling, or 6.5 cycling in busy London traffic, but the average for an air conditioned diesel train was 8.5. That is pretty shocking. I wonder why, is it to do with where the air intakes are in relation to the exhausts? Obviously the ideal is to move to electric rail, but we do need to design our diesel trains differently too. My worry is that rail will start to become the dirty mode of transport. It is the enviromentally friendly choice at the moment, and the industry needs to ensure it stays that way.
 

hairyhandedfool

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..... I wonder why, is it to do with where the air intakes are in relation to the exhausts?....

I wonder if there is a significant difference between air conditioned diesel trains and other diesel trains. Granted there aren't many modern diesel trains that are not air conditioned, but I think that might also make for interesting reading.
 

Mikey C

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Very interesting numbers and slightly disturbing.

What filters do they have to clean the air before it enters the aircon system?
 

AM9

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The article is really interesting to read in detail. Some of the findings were logical - sitting in the house got a low reading - while sitting in a black cab in traffic got the highest reading. But, the rail results were surprising, and not in a good way. The reading was 1.7 for walking around town, 2.1 for driving, 3.7 cycling, or 6.5 cycling in busy London traffic, but the average for an air conditioned diesel train was 8.5. That is pretty shocking. I wonder why, is it to do with where the air intakes are in relation to the exhausts? Obviously the ideal is to move to electric rail, but we do need to design our diesel trains differently too. My worry is that rail will start to become the dirty mode of transport. It is the enviromentally friendly choice at the moment, and the industry needs to ensure it stays that way.

Would it be that rail fumes tend to hug the profile of the rolling stock (LHCS or MU) rather than disperse outwards as for motor pollution. In addition to that, much of the rail infrastructure is in cuttings and in cities tunnels. Observe how the fumes gather around the rear of a moving train and at tunnel entrances, even get sucked into the tunnel by the low pressure following the last vehicle.
Then there is the smell of the last train to pass through the tunnel in either direction. Many is the time that a strong diesel fume smell invades Thameslink trains as they pass through the cuttings at Carlton Road junction, the tunnels under Hampstead Heath and out to West Hampstead, and that is when they follow said MML train by crossing at Carlton Road. These fumes must be hanging around for at least 3 minutes.
For whatever reason the Swiss originally electrified their railways, they made the right decision given the pollution and health issues that steam and diesel propulsion bring to the railway. In pollution terms, it would be better to save as much of the new rolling stock capital budget as possible and spend it on electrifying as many additional lines as possible. This would be better even if it meant that older but serviceable stock needed to continue in service for longer.
 

Greybeard33

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In pollution terms, it would be better to save as much of the new rolling stock capital budget as possible and spend it on electrifying as many additional lines as possible. This would be better even if it meant that older but serviceable stock needed to continue in service for longer.
The pace of electrification is determined more by the availability of engineering resources than the capital budget.

I think the most worrying finding of the BBC report is the high level of particulates measured inside diesel trains, both between Bedford and St Pancras (presumably Meridians) and between London and Exeter (presumably a HST). I fear this could result in pressure for expensive modifications to retrofit exhaust diesel particulate filters to most of the existing DMU, DEMU and HST fleets.
 

AM9

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The pace of electrification is determined more by the availability of engineering resources than the capital budget. ...

Of course it isn't viable to (attempt to) electrify at a rate greater than available resources allow, - witness the delays incurred in the current and planned projects. However, despite the recent rush to electrify, there have been many years where lack of budget has been responsible for missed opportunity, and critically, wastage of the engineering capability already available leading to much of the shortages and delays of the present. Available capital budget in the greater government sense determines not only the amount of capital for electrification projects, but also the level of engineer training for the future. This problem is not only limited to rail electrification resources, - look at doctors, nurses teachers etc. Whilst it indicates the short-sightedness of governments (of all flavours), only rail resources are on topic for this thread. Who knows how long it will be before the brake is applied to the overall programme for electrification again?

So, back to my original statement, a part of the total cost of most major new electrification projects is for new rolling stock. If that part was (where possible), instead used to further the total amount of electrified infrastructure* by making do with serviceable cascaded rolling stock, which would be replaced with larger, more cost effectve buys. The current obsession with marketing a newly electrified line with shiny new trains often consumes budget that could be more effectively used to enable more progress in eradication of the gross (local) polluter that diesel traction is becoming.

* Increasing the rate of infrastructure electrification may include a small increase in the number of trained engineering resources. Of course, once they are trained, these resources would be available for all future projects.
 

TH172341

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Interesting to read - and certainly a good reason of the need to electrify in the long term.

I wonder though what a comparative reading would be on say a 172, or in the near future, a Class 800 or CAF DMU. I dare say it would be far better thanks to the improvements in particulate filters over the last decade since the 22X series and certainly the 159s. It's a similar case in the aviation field, where the new engines being brought out are far more environmentally friendly than their predecessors that are not that much older in design terms.

However suppose it is all relative - we're always being exposed to pollutants, and it doesn't impact too adversely on our lives seemingly considering our life expectancy is constantly on the up. Dare say pollutants would've been even worse in steam days, and when Deltics were roaming around, particularly for the firemen and drivers.

Suppose today drivers might be exposed to slightly less than the passenger compartment considering on most types you can crank open the window, which at speed would be drawing in the fresh air from in front.
 

Xenophon PCDGS

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I agree entirely. Operators of older DMUs, in particular, must not only cause significant tonnages of needless pollutants, but also waste an enormous volume of fuel (and money) having seemingly no requirement for the engines to be shut down during layovers. If the reliability of the batteries or other components is that poor then get your engineering bods to sort it out!

I remember one especial unsavoury episode some time ago when on a Northern Class 150 service bound for Clitheroe when it stopped at Salford Crescent with the unit door wide open for a few minutes and the diesel fumes that entered the carriage were very unpleasant indeed.
 

Bletchleyite

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It always seemed quite common, probably still is, for 15x to emit fumes from the underframe area rather than just the exhaust pipes. Was never quite sure why (leaky exhausts?) but those did tend to go in through the open doors and windows.

But my prize for worst (worst everything, really, Pacers aside) is the Class 166, which just stinks of fumes all the time.
 

exile

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I wonder if anyone has thought of having all the diesel engines in a train in one vehicle - which could be called a "locomotive" - instead of distributed throughout the train.....
 

All Line Rover

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Was it a Meridian or HST from Bedford? I would be shocked if it was a Meridian considering they (and Voyagers) are sealed like tanks. A HST would not be so surprising. Local diesel trains even more so.
 

R4_GRN

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Most times I see a diesel engined train starting up there seems to be a large ammount of exhaust fumes, is this due to the large size of the engine or is it caused by poor fuel injection? Poor maintenance or a worn engine. I know diesel tend to over fuel to cold start but I mean when engine is warm and revs increased to pull away.
Any train engine engineers explain?
 

3141

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However suppose it is all relative - we're always being exposed to pollutants, and it doesn't impact too adversely on our lives seemingly considering our life expectancy is constantly on the up. Dare say pollutants would've been even worse in steam days, and when Deltics were roaming around, particularly for the firemen and drivers.

Absolutely.

The article is the kind of thing journalists love doing - "here is a problem, oh dear, it's really worrying..." - and some people do start to worry. But while they told us where the readings were higher, what they didn't do was to relate those levels to what might be dangerous, and what doesn't greatly matter. The world we live in depends on the consumption of fuels for a great many purposes, and inevitably there are emissions.

As for there being 29,000 deaths per year that might not have occurred when they did if emission levels were lower - well, yes, and there are thousands of others because people drink too much alcohol, or don't take enough exercise, or we don't have mass screenings for everything, or even because some people suffer stress after reading articles like that one. But what would be the situation if all those people lived for ten years longer? Maybe we wouldn't be happy to see greater pressure on housing, or even more new housing being built to accommodate the additional numbers, or the resulting pressures on other services.

To travel between my home at Overton and London Waterloo I normally use a class 159. I do not intend in future to change at Basingstoke onto an electric train.
 

Greybeard33

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I wonder though what a comparative reading would be on say a 172, or in the near future, a Class 800 or CAF DMU. I dare say it would be far better thanks to the improvements in particulate filters over the last decade since the 22X series and certainly the 159s.
The 172 only complies with Stage IIIA requirements, which permit nearly ten times the level of particulates allowed under the current Stage IIIB. All earlier DMU and DEMU classes are exempt from any emissions requirements. I believe the Class 800/801 will be the first British units to be fitted with DPFs.
I wonder if anyone has thought of having all the diesel engines in a train in one vehicle - which could be called a "locomotive" - instead of distributed throughout the train.....
You mean like the HST that gave an equally high reading in the BBC tests?
Was it a Meridian or HST from Bedford? I would be shocked if it was a Meridian considering they (and Voyagers) are sealed like tanks. A HST would not be so surprising. Local diesel trains even more so.
I believe nearly all the EMT services that call at Bedford are booked as Meridians. Sealing does not help if the aircon sucks in the exhaust fumes.
 

DelW

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Last week I made two overnight trips in Thailand, travelling in air-conditioned sleepers built by Daewoo in 1996. Although they are loco-hauled, these coaches each have an underframe-mounted diesel engine providing air-con and electric power, and they seemed very prone to sucking in fumes when stationary. At one stage we were waiting at the Thai - Malaysia border for around two hours (awaiting a Thai loco to continue north), and the diesel fumes became really unpleasant on board. Fortunately the problem disappeared when we were were moving. So it's not just a UK problem, or even just a DMU problem.
 

furnessvale

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I wonder if anyone has thought of having all the diesel engines in a train in one vehicle - which could be called a "locomotive" - instead of distributed throughout the train.....

And if we were really clever we could call it a.......DELTIC....because they were REALLY fume free, especially after idling for a while. :D
 

The Ham

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Could part of the problem be the pollutents entering the trains at covered stations and then having little chance to escape.
 

devinier

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Absolutely.

The article is the kind of thing journalists love doing - "here is a problem, oh dear, it's really worrying..." - and some people do start to worry. But while they told us where the readings were higher, what they didn't do was to relate those levels to what might be dangerous, and what doesn't greatly matter. The world we live in depends on the consumption of fuels for a great many purposes, and inevitably there are emissions.

As for there being 29,000 deaths per year that might not have occurred when they did if emission levels were lower - well, yes, and there are thousands of others because people drink too much alcohol, or don't take enough exercise, or we don't have mass screenings for everything, or even because some people suffer stress after reading articles like that one. But what would be the situation if all those people lived for ten years longer? Maybe we wouldn't be happy to see greater pressure on housing, or even more new housing being built to accommodate the additional numbers, or the resulting pressures on other services.

To travel between my home at Overton and London Waterloo I normally use a class 159. I do not intend in future to change at Basingstoke onto an electric train.

Are you for real ?
Have a look where the air intakes are for the aircon, in relation to the exhaust outlet, on the 159 you ride into Waterloo on. Hopefully you're not one of the unlucky 29,000 (or whatever the figure is).
 
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jopsuk

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I wonder if anyone has thought of having all the diesel engines in a train in one vehicle - which could be called a "locomotive" - instead of distributed throughout the train.....

The trains mentioned- and measured on- in the article seem to be the HSTs. So, erm, yes.
 

AM9

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Absolutely.

The article is the kind of thing journalists love doing - "here is a problem, oh dear, it's really worrying..." - and some people do start to worry. But while they told us where the readings were higher, what they didn't do was to relate those levels to what might be dangerous, and what doesn't greatly matter. The world we live in depends on the consumption of fuels for a great many purposes, and inevitably there are emissions.

As for there being 29,000 deaths per year that might not have occurred when they did if emission levels were lower - well, yes, and there are thousands of others because people drink too much alcohol, or don't take enough exercise, or we don't have mass screenings for everything, or even because some people suffer stress after reading articles like that one. But what would be the situation if all those people lived for ten years longer? Maybe we wouldn't be happy to see greater pressure on housing, or even more new housing being built to accommodate the additional numbers, or the resulting pressures on other services. ...

So problem fixed. Just need to keep running the highest polluting trains to reduce the demands on housing AND reduce the capital costs of buying new stock. I presume that you advocate driving Trabants as well! :)
 

Andyjs247

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I'd like to see some further study. For example how much pollution is background pollution and how much is from the train itself. So measure the same unit at say BHM or GLQ and again after its had a run out on the Cambrian or Highland Main Line, where the air would be cleaner.
 
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