6023

6024's problems have always been coal related, when it has the right coal it is has turned in some remarkable performances. I wonder if 6023's modifications will allow it to steam better on variable coal? That would really be a big advantage for a western engine on mainline metals.

 

No idea but an 8 jet blastpipe sounds fun!

 

It would be a real organ recital on wheels!

 

The maximal size of the orifices in the 6024 case is determined by the blastpipe internal diameter, if it is 5 inch orifices cannot surpass 2.5 in each and it would need a careful look to determine whether this is workable with the chimneys.
Kind regards
Jos

 

That's a pity as you might find that discussing engineering with an engineer is illuminating.

"if you really believe an earth shattering roar is a sign of efficiency" Did I say that?

If you had claimed that sophisticated multi jet exhaust systems have softer characteristics I would have agreed with you - but to extrapolate that to "soft exhaust good - sharp exhaust bad" is an oversimplification. If you were to listen to various locomotives with conventional front ends you would find that they have different sound characteristics (what we call "subjective noise" in my workplace - and is measured by the average score of a jury voting - whereas absolute noise is of course measured in dB) - and many people over the years have described GW locomotives as having a crisp exhaust note, a "bark", "whip crack" or "square blocks". H C Casserley wrote:

The distinctive sounds of engines of many of the old Companies were, and still are, easily recognizable by the expert. There is no mistaking the somewhat nasal exhaust of a Great Northern Ivatt tank, the deep-throated voice of a Midland class 4 goods or Derby 4-4-0 rebuild, the staccato bleat of a North Western- " Prince ", now no longer heard, or the sharp business-like exhaust of a modern Great Western engine.

Rightly or wrongly Nock ascribed that to the semi-plug piston valve:

The passage of the steam through the valve was controlled by the outer edges of the snap rings. On modern narrow ring valves, with the outermost valve set well in from the edge of the valve head, the body of the valve forms a restriction when the valve first opens. In the GWR valves the body of the valve was well clear of the steam edge of the snap rings and offered no restriction. This was a good feature. It was the unrestricted flow at the instant of opening which gave the GWR engines their characteristic bark at starting, and the machine-gun crack of the exhaust when working hard at speed. It also explains why, when some GWR engines were fitted with BR valves, it was found necessary to work them at a longer nominal cut-off than usual.

There is an inference in your comments that GWR locos had restrictive exhausts - and with Ell's single chimney modifications you might be right. However the original designs tended to have quite generous proportions. Gresley's Silver Link achieved 112 mph with a GWR style jumper blastpipe - the same diameter (5.25") as a Hall and smaller than a King.

 

FWIW I fear I may have inadvertently started this (quite literally) barking argument.

My comment was merely based upon a common point I heard from my dad who was old enough to have grown up with single chimney Kings (and I think was actually working inside when they were upgraded) and also from his friends from his time inside the works, namely that whilst the double chimneys inevitably made them a more efficient locomotive it was very sad that they lost their distinctive bark after they were so fitted.

 

In other words a double Kylchap (more or less)?

 

Just add roller bearings... How free running and steaming could that be?

 

As a non-engineer I'm not competent to comment on the efficiency of steam loco exhausts, but there is something spine-tingling about the sound of a powerful engine working hard. I've noticed the "bark" particularly with castles. Double chimneys may soften things, but the Earl has a damned good "woof" and I remember a very distinctive bark when watching 6024 depart from Paddington a few years ago. Barking is not confined to GWR locos, either. If you've ever watched Duchess of Sutherland pulling away vigorously from a station on a quiet night, without diesel assistance, the bark can rattle your fillings. I wonder if this has anything to do with 4 cylinders and the GWR derived front end.

 

I think double chimneys on Castles and Kings didn't necessarily lead to a quieter exhaust bark. The 5043 and 6024, both with double chimneys, have demonstrated many times how they can produce a tremendous roar and loud bark when starting. I think it was Bob Meanly who once said on this forum that double chimney Castles were at least as loud as the single chimney version and that when the first ones were converted, drivers thought they were working the locos harder than they actually we're, from the loud exhaust beat, and could loose time.

 

Are locomotives with a loud bark more likely to break up the fire?

 

Surely the question should be "Is draughting sufficiently fierce to break up a fire bed always reliably indicated by a loud front end bark?"

 

Having fired 30541 (aka Dr Noise) a few times, I wouldn't say that a loud bark causes the fire to break up. Does drag it forward a bit on that though.

 

Great shame that 6023 is not destined for the main line. Then we could see how she really goes with Meneer Koopmans modifications.

 

Not necessarily, "likelyhood" and "reliable indication" do not mean the same thing.

 

My thinking exactly. I was hoping that 6023 could go main line and set new performance standards for the King class.

 

I believe the GWS's position is to wait for Network Rail's goalposts to stop moving and then to reconsider which if any of their locos can go out on the main line. If 6024 never does so, and only ever chuffs up and down preserved lines at a maximum of 25 mph, all the work of designing lower fittings and Jos's work on the drafting will have been to no real end.

 

Please consider the fact that even on the demo line in Didcot 6023 showed considerable savings on coal! That 350 UKP has been earned back a longtime ago.

 

If you are a qualified steam locomotive design engineer, I bow to your greater knowledge. If not, perhaps you should be a little less patronising.