Steam Loco exhaust, ex-34081 - 92 Squadron

Surely the most important thing with any coal is its ability to produce heat and boil water!

 

Maybe a second look at the Bulleid-Lemaitre exhaust might help! It is not the same coal anymore.
kind regards
Jos Koopmans

 

Given that much of what gets blasted skywards is unburned fuel, I have often wondered whether Bulleid's boiler wouldn't benefit from a gas producing grate. Whilst photographers mightn't universally welcome a clean exhaust, I somehow doubt those with sight of the coal bills would mind too much.

 

Well tough!

PH

 

The problem in 2017 is you take what you can get coal wise, there are very few mines that are supplying loco grade steam coal, i can remember from my firing days how bad it could get , coal that sat on the grate, then eventually decided to burn, other stuff that was like rocket fuel and it burnt away to nothing as soon as you put it on, other that made smoke even when you as wayne has said fire to avoid smoke, it was a ballancing act, to have a good head of steam, minimum smoke, and not run your fire down to much, i can remember some russian coal, horrible stuff, very smoky, slow to ignite, clinkered to hell, luckily i had some decent stuff underneath this rubbish so was able to mix good and bad.

 

Martin,

That is the responsible attitude, sadly not universal on this thread. It is possible to get fuel which is almost utterly smokeless, hot burning and, so I am told, not excessively prone to clinker. Of course, the proviso is that with open cast mining, load will vary from load.

Some of these pictures suggest that a railway would not have to suffer from particularly NIMBY neighbours for great exception to be taken to this sort of atmospheric pollution, even on an occasional basis. Someone needs to say "Sorry will not happen again" and say it quickly.

Paul H

 

If I read the comments on the Shotton coal, it appears to be of an anthracite nature. This has a higher ignition temperature and will evaporate
bituminous content instead of the gases from steamcoal proper. Trying to combust the bituminous products with relatively cool air from the firedoor
will not work. Instead the firedoor should be closed asap and as much air drawn through the grate to get the coal to ignite.
Imho the front-end of the MN class has a problem with the distance of the orifices to the chimney. Ell specified 6-7 diameters for "normal" chimneys
but did not apply that to the 5-0rifice Bulleids. Modern research shows him to be absolutely right, it is an optimal distance and the Bulleids are victims.
Kind regards
Jos Koopmans

 

Post #17 is worth re-reading.

 

It is high level atmospheric pollution regardless. Not something to be perpetrated just for the amusement of photographers.

PH

 

I always tried to keep smoke to a minimum, and to avoid blowing off when stopped at stations, its a sign of bad firing to make excessive black smoke or to lift a valve we have all lifted a valve at some point,in my defence it was often when we were delayed and i had a full pot, and fire made up ready for an on time departure and i did not want to have carry over when the regulator was opened, ok i was lucky to be taught by a former BR steam driver, how to fire , using the little and often method .
I can remember being told that we must not put anything on at Alresford, make smoke, or blow off, so we had to ensure we made the fire up on the run in, play with the injector to maintain a good water level, then fire on the run to Ropley.where we took water, so we had time to sort the fire out .

 

One other thing was professional pride, in doing your job right, as i explained, At Ropley you can guarentee that if you made too much smoke, or blew off, the workshop staff and fellow firemen would be watching your every move and on return to shed, you would have a" did i see you try to black out half of Hampshire?" or " we had to stop short because we couldn't see through your smoke , or can you speak up, I'm' deaf after you lifted that valve " you did not get away with anything.

 

I reckon I'd put 'not damaging the engine' in front of that, actually.

Noel

 

Bulleid's or anybody else's.

 

If too little air is supplied there is a lot of unburnt fuel. The gas producer system was right for higher ash contents and prevented fusing of the ash
since it lowered the firebed temperature. I do not see a useful application for low ash content coal, with sufficient draft it should properly burn.
That impressive chimney of the Bulleids is almost useless since due to the distance of the orifices all combustion products are entrained already.
Kind regards
Jos Koopmans

 

Accepting Jos's knowledgable observation completely regarding ash content, exhausts of large locos working hard still makes me wonder about emissions of unburned particulates. Whilst front end mods to better suit available fuel make perfect sense, would these alone represent a complete solution? I well recall Giesl fitted 34092's sparkling performances during mainline days, and comments from BR traction inspectors about the loco being "two carriages stronger", whilst clearly retaining markedly volcanic tendancies, hence my interest in the combustion cycle.

 

Chicken and egg, some fuels no doubt benefit from a stronger blast but foer some this means you are more likely to need spark arresters/ deflectors/screens etc,
Spark arresters/ deflectors/screens etc, mean you are likely to need a stronger blast, .....or other means of maintaining a good smokebox vacuum, hence the original Fighter command Geisl experiment.
These systems aren't perfect and aren't 'one size fits all' and the size you fit depends on the results you want. As Jos has pointed out a correctly proportioned/positioned Lemaitre, may well have done the job. Cant honestly say whether the City of Wells Geisl. which Dr Geislingen had some direct involvement in, is the same size as 34064's either...

 

Given the supposed correctness of my present momentum calculations, I can acknowledge above statement! Seven instead of the present five orifices, same diameter, but properly positioned, would have given almost the same vacuum that Ell measured and Giesl probably equaled with a larger orifice area.
Kind regards
Jos Koopmans

 

That is the reality of running steam on the mainline in 2017, Coal, that can vary in standard with in the same delivery, and the pathing issues given to you my NR, you have to put the health of the loco first, so that means keeping the grate covered, and a safe water level at the glass, water in the cylinders is not good news, i would rather have the valves up to make space, than risk carry over if i'm honest, as i dare say would anyone who has been in that situation .