Uncle Roger and engine emissions

[w124bob]

Just for some balance

 

 

[mikejames]

not balance - but a very good reason to look very hard at restrictions on diesel use in the uk.

for some reason some people are impressed by an exhibition of cleg/clag? from deltics and other diesels

but to me its a serious health risk

 

sorry but no thank you

 

 

regards

mike j

 

 

[Edwin_m]

Not just the government.  The privatised Railtrack was totally uninterested in electrification too. 

[roythebus]

On 21/03/2019 at 22:24, Davexoc said:

All pretty irrelevant really, because if we were bothered we would all catch the bus or train.

Alternative is drive single occupancy the most gas guzzling largest SUV status symbol your income can afford and have the next best one down for the wife for the school run and coffee mornings with the like minded mummys.....

 

 

Yep, that's us, I've got a Range Rover with the big diesel engine and my partner has a Discovery with a very low emission diesel, so low it goes into the LEZ for free as it's classed as a low emission van.

[jjb1970]

I must admit, the sight of engines belching smoke annoys me profoundly, as there is just no reason it these days.

 

What comes out of an engine exhaust is determined by what goes into the engine. As with any chemical reaction (or series of reactions), both sides of the equation must be balanced.  However the nature of what comes out (for example, does the carbon come out as CO2, CO, particulate matter) is largely determined by the combustion process (and any abatement techniques used). Which means that if talking about exhaust it is a combination of what you put into the cylinder (fuel and air), how you combust it and whether or not you have any downstream abatement. Something to note is that abatement devices don't just make pollutants go away, they may capture them or reform them into something considered less harmful but the fundamental truth of what goes in must come out somewhere remains.

 

You can do oxy-firing (i.e. substitute air with pure oxygen) but it is hugely expensive and is more of a theoretical possibility and lab technique than a real option for working engines. So you combust air, since air is mainly nitrogen then that means NOx is an issue, depending on combustion temperature and dwell times. The fuel tends to be what introduces the worst pollutants, fossil fuels are hydro-carbons and so you are introducing carbon into the process. A pure hydro-carbon fully combusted would actually produce quite a straightforward exhaust, CO2 and water. Unfortunately, fuels are not pure hydro-carbons and contain a range of other materials such as sulphur, and achieving perfect combustion is not as easy as it sounds. If you combust hydrogen in an IC engine, then CO and CO2 isn't a problem. Something interesting about NOx formation is that nitrogen entrained in fuel behaves differently from nitrogen in air during combustion and so in the case of NOx it is not as simple as just nitrogen in air reacting with oxygen. Particulates which make black smoke are basically uncombusted fuel, how harmful they are is dependent on the nature of the PM (for example, Black Carbon is particularly undesirable) and particle size. Although the larger particle sizes tend to make more visible smoke and look worse but in terms of health effects the smaller sizes tend to be worse. When considering PM there is a lot of disinformation and spin as unless the species of PM is specified then take things with a pinch of salt. Depending on the type of fuel you can get heavy metals and all sorts of toxins in fuel which leave the cylinder with the exhaust gas unless they end up deposited on exhaust valves, the exhaust trunk, piston crowns etc (vanadium as vanadium pentoxide can do terrible things to exhaust valves). Trains in the UK use 10ppm highly refined distillate fuel so it's pretty clean, but if thinking about heavier residual fuels or coal then exhaust can be an awful toxic cocktail.

 

The combustion process is also subject to variables and how it is controlled. The main one is the fuel - air ratio, the theoretical ideal is stoichiometric combustion but that is another ideal. At a simple level, you increase power by increasing the rate of fuel combustion which means you need more air as well. Modern engines use much more advanced fuel injection control than older engines, both in terms of quantity of fuel, when it is injected and where it is injected in order to control the combustion process. At this point thermodynamic cycles rear their head (the term "diesel" engine is generally a misnomer as there are a range of engine cycles) but that's another story.

[Dunsignalling]

On ‎21‎/‎03‎/‎2019 at 23:52, Covkid said:

 

With respect, those trains should never have been built with hydraulic transmissions.

They should have been diesel electric transmissions, so that they could be easily modifiable to use the juice rail where possible.  

 

The DMu designs currently in use that have hydraulic transmissions, date from a time when electric transmission came with a significant weight/size penalty which impacted upon unit design, fuel efficiency and emissions.

 

That would have had a significant effect on "my" bit of railway, where all those excess kilos would have been working all the way from Exeter to Basingstoke, before picking up the juice for the shorter, and less arduous, leg into Waterloo. It may well be that the fuel a 159 saves over what a D/E equivalent of similar vintage would use on the first bit exceeds that expended on the second. 

 

Newer diesel-electric generation/traction sets have largely overcome the drawbacks in older ones and, for new construction, I would entirely concur.

 

John

Edited March 23, 2019 by Dunsignalling

[Fat Controller]

14 hours ago, mikejames said:

not balance - but a very good reason to look very hard at restrictions on diesel use in the uk.

for some reason some people are impressed by an exhibition of cleg/clag? from deltics and other diesels

but to me its a serious health risk

 

sorry but no thank you

 

 

regards

mike j

 

 

They weren't that interested in railways per se, were they? They seemed to view them as an embarrassing complication occupying potential development sites..

[Hesperus]

The 159s would be far better deployed elsewhere and a electro-diesel unit introduced in their place.  They are amongst the best DMU's available in the country and even if electrification policy was reversed tomorrow there will still be thousands of miles of non-electrified route for them to work when they retire in 10-20 years time.  If the engineers want something to tinker with then there are hundreds of EMUs looking for new homes.  Perhaps a small coach with a diesel engine and alternator could be attached like on the new Flirt units?  To save the need for a corridor through it you could put it at the far end of the train like a 21st century 33/1.  With one big engine providing the power rather than a dozen small ones any exhaust scrubbing you needed to add would be cheaper and easier too.

 

I really do despair about this subject.  Billions of pounds is being spent trying to electrify the road network with battery vehicles which are fine for commuters cars but are going to be hopelessly inefficient for larger vehicles or longer distances as the batterys need to be huge.  Just electrify the railways and increase fuel tax until long distance traffic moves to them.  Big cities could reintroduce trolley buses making use of modern batteries to give flexability the old ones lacked.

 

I write this as a country dweller who drives his diesel car 6 miles to work as there is no alternative,  I'll get an electric one when the prices drop (or the fuel prices rise).

[Dunsignalling]

1 hour ago, Hesperus said:

The 159s would be far better deployed elsewhere and a electro-diesel unit introduced in their place.  They are amongst the best DMU's available in the country and even if electrification policy was reversed tomorrow there will still be thousands of miles of non-electrified route for them to work when they retire in 10-20 years time.  If the engineers want something to tinker with then there are hundreds of EMUs looking for new homes.  Perhaps a small coach with a diesel engine and alternator could be attached like on the new Flirt units?  To save the need for a corridor through it you could put it at the far end of the train like a 21st century 33/1.  With one big engine providing the power rather than a dozen small ones any exhaust scrubbing you needed to add would be cheaper and easier too.

 

I really do despair about this subject.  Billions of pounds is being spent trying to electrify the road network with battery vehicles which are fine for commuters cars but are going to be hopelessly inefficient for larger vehicles or longer distances as the batterys need to be huge.  Just electrify the railways and increase fuel tax until long distance traffic moves to them.  Big cities could reintroduce trolley buses making use of modern batteries to give flexability the old ones lacked.

 

I write this as a country dweller who drives his diesel car 6 miles to work as there is no alternative,  I'll get an electric one when the prices drop (or the fuel prices rise).

Very probably, but that presupposes that South Western Railway has both the funds and the inclination to replace them (they have neither AFAIK).

 

Whatever replaced them would also have to burn no more diesel between Basingstoke and Exeter than the 159s do over the whole journey, or there's no overall gain to be had, either economically or ecologically. I they didn't, it would require a (perhaps divisive) political decision to reduce emissions in the electrified area, whilst consciously increasing them elsewhere.

 

I suspect that, when the time comes, the arrangement used in the Flirt units may be the answer, in new or re-used units which suggests that something resembling the former Southern Region's common-sense approach to interoperability may be re-emerging. Incidentally, I understand there is a gangway through the Flirt powered coach. 

 

I too am a rural diesel car driver, and also use it relatively little as I try to walk or use public transport for those journeys where it is suitable. I consider that the carbon footprint involved in producing an electric replacement might take a good few years to be recovered from eliminating the emissions I am responsible for - after all, my car is as much a zero emissions car as any other, until I start the engine.

 

John

Edited March 23, 2019 by Dunsignalling

[Edwin_m]

Good as the 159s are, their diesel engines are old enough that they don't have to comply with any emission standards.  A modern equivalent DMU would have to comply with the latest ones so would emit a good deal less particulates and NOx and probably less CO2 too.  That's before thinking about any savings from making it a bi-mode and using electric power for a large part of the journey.  By the time of the next franchise a 100mph bi-mode should be available moreorless off-the-shelf from several suppliers. 

[ess1uk]

On 22/03/2019 at 10:08, Covkid said:

 

You are in the same boat as me Mike !!! We are semi reliant on the media for information, from which we then have to make our our decisions on what is and isn't true, and what is and isn't viable.  It seems that diesel is becoming a dirty word and alternative power sources are sought. We are told diesels will be "outlawed" from 2040 which leads us to suppose that sales of diesel powered vehicles will fall off between now and then. 

 

I hear of "electrification" in aviation and in the motor industry which basically means using electricity as a means of propulsion. Obviously the new diesel / dual powered trains rolling off production lines for TPE, ARN, GA etc were ordered several years ago, with then state of the art diesels, but what is the future ? I find it very difficult to accept that the brand new EWR (East West Rail) is being planned as a non electrified line when it connects two of England's centres of learning - Oxford and Cambridge  There are suggestions it might be electrified later, but that is an unacceptable situation to be in, for engineers seeking possession of a line for engineering work.  Much easier and more convenient to build a brand new railway completely (notwithstanding Oxford-Bletchley is on existing formation) than subsequently close it to the users to erect catenary and power systems.  

 

Quite what kind of non electric trains are being planned for this route is intriguing, ruling out diesel it can only really be hydrogen or battery in my view.      

 

 

But what gets me is

Bletchley is wired

Bedford is wired

Sandy is wired

Cambridge is wired

and Oxford is supposed to be wired

how hard would it be to fill the gaps?

[jim.snowdon]

For engineers who understand the realities of common sense electrification and its effects on signalling, not difficult.

For politicians and civil servants who believe they have been shafted by the as yet unfinished GW project, who lack strategic vision and are easily sold "innovation", very difficult.

 

Jim

[iands]

4 hours ago, jim.snowdon said:

For engineers who understand the realities of common sense electrification and its effects on signalling, 

 

And telecoms, please don't forget telecoms.

[russ p]

One thing this thread has done is made me go online and buy a kit to remove the EGR valve from my MGZT diesel , together with a remap its now 175bhp instead of 131 and doing 45-50 mpg instead of 40

[jim.snowdon]

8 hours ago, iands said:

And telecoms, please don't forget telecoms.

Granted, although how much of the telecoms network is now on fibre optic rather than copper (hopefully as twisted and screened pairs in any case)?

 

Jim

[Nearholmer]

I did wonder quite how FO would be affected, but presumably the presence of all that aerial metalwork does affect radio propagation.

[ess1uk]

5 hours ago, jim.snowdon said:

Granted, although how much of the telecoms network is now on fibre optic rather than copper (hopefully as twisted and screened pairs in any case)?

 

Jim

Most of it is on fibre except for the last mile or so, just like your home provider.

newer schemes are even IP over fibre right to the signal location cabinet.

Edited April 23, 2019 by ess1uk

[ess1uk]

10 hours ago, Nearholmer said:

I did wonder quite how FO would be affected, but presumably the presence of all that aerial metalwork does affect radio propagation.

Doesn’t seem to be that bad with the OLE but other MNOs are a bigger problem in some areas so GSMR repeaters are deployed.

certainly can’t use that as an excuse not to electrify 

the Hertford loop is OLE and ERTMS works there

Edited April 23, 2019 by ess1uk

[iands]

14 hours ago, jim.snowdon said:

Granted, although how much of the telecoms network is now on fibre optic rather than copper (hopefully as twisted and screened pairs in any case)?

 

Jim

Hi Jim,

There is still a large amount of copper cable out there on the railway, and will be for some considerable time. Yes, 'telecoms' use "twisted" pair cables and have done since open line wires were phased out. However, traditionally, signalling didn't use twisted pair cable for donkey's years as their application was different to telecoms applications - as one well respected senior signalling engineer once said to me in a meeting (tongue -in-cheek) "ah yes, but you in telecoms want to do daft things with your cables like talk over them, all we want to do in signalling is operate a relay"! Admittedly the comment was in connection with "insulation" requirements rather than "immunisation" issues. However, these days signalling do seem to be using more twisted pair cables in their applications.

[Nearholmer]

For a new, infill, electrification, wouldn’t the telecom be fibre to within a few metres of whatever was being controlled or detected? I’m assuming that the signalling would use radio to/from the train.

[iands]

29 minutes ago, Nearholmer said:

For a new, infill, electrification, wouldn’t the telecom be fibre to within a few metres of whatever was being controlled or detected? I’m assuming that the signalling would use radio to/from the train.

In an ideal world, yes, but not every piece of S&T railway lineside kit has an available  (and I mean "economical") "optical interface". Even with FO cables and digital networks along the lineside that have largely replaced the long-haul copper trunk cables and FDM trasmission systems of yore, there are still plenty of what are termed "copper islands", copper cable infrastructure, that are still needed on a "local" basis for final connectivity (as ess1uk alluded to, although the "mile" reference is more an arbitrary term rather than a literal term). As for signalling using radio to/from the train, this is all wrapped up in ERTMS (and relies heavily on telecoms networks/systems anyway). Despite what you might read in the "press", this is still quite a way off yet from wholesale use, or even on an "infill" bit of electrified railway.

[ess1uk]

48 minutes ago, Nearholmer said:

For a new, infill, electrification, wouldn’t the telecom be fibre to within a few metres of whatever was being controlled or detected? I’m assuming that the signalling would use radio to/from the train.

For mml upgrade Siemens have been deploying IP over fibre signaling.

telcom network between Bedford and Corby is being upgraded to carry it back to Derby 

[Nearholmer]

My thinking was that the elongated thicket that is currently the Bedford-Oxford line looks largely railway signalling and telecoms free, so one would expect to start afresh with the latest tech, which notably simplifies matters from an immunity perspective.

 

[ess1uk]

10 minutes ago, Nearholmer said:

My thinking was that the elongated thicket that is currently the Bedford-Oxford line looks largely railway signalling and telecoms free, so one would expect to start afresh with the latest tech, which notably simplifies matters from an immunity perspective.

 

Oxford to Bicester telecomms would have been upgraded on the 3 Evergreen projects but will be old technology in relative terms so will probably need upgrades again.

Bedford to Bletchley Telecommunicatons is probably about 12 years old now so would need an update.

the mothballed bit in the middle will only have Calvert with 10 year old comms but that’s all moving for HS2 anyway.

so any rebuilding will be done with new S&T which will probably be IP over fibre to the location anyway, thus ready for OLE if it ever comes

[jim.snowdon]

Not forgetting that if there is a railway environment that is electrically noisy, it would have to be the Southern's DC network, where the currents, and thus magnetic fields, are around two orders greater than those of the AC railway.

 

Jim