Many thanks John for this marvelous postington - I have been wondering about what a Giesel ejector is and how it works as only last week I purchased on Yahoo auctions one of Mr Kato's models of a Giesel fitted D51 Hokkaido cold weather spec loco as used up until 1975. Train Trax has a description here.

I am now educated in the mystery!

Colin.

Quote from: cmason on October 21, 2025, 07:08:58 PMMany thanks John for this marvelous postington - I have been wondering about what a Giesel ejector is and how it works as only last week I purchased on Yahoo auctions one of Mr Kato's models of a Giesel fitted D51 Hokkaido cold weather spec loco as used up until 1975. Train Trax has a description here.
I am now educated in the mystery!

There's nothing particularly fancy about it, it's just a more refined form of blastpipe.

Instead of the exhaust steam being simply blown up a big hole (the chimney) with a broad petticoat pipe to make sure it does go up the hole, the Giesl ejector is a more finely tuned combination of a converging coned blastpipe, a converging combining cone to add the smokebox gases and a diverging cone to exhaust the combined exhaust steam and smokebox gases out of the chimney - all multiplied by the required number of these to both allow the cylinder contents to be properly exhausted and to give the required "draw" through the fire and boiler tubes.

It works on exactly the same principle as a brake ejector, water feed injector or, even, a car carburettor.

A Coarse Guide to the Steam Locomotive for 'N' Gauge Modellers - Part 102


Hello Chums

The Final, Exhausting Section of Our Gloriously Brief Mini-Series

'Multiple Jets - Kylchap'

Let's begin with a questioningham. How many of the 'Big Four' grouped railways used the Kylchap exhaust?

Now, to France. Mr, later Sir Nigel, Gresley [for simplicity, let's abandon chronological exactitude and refer to him as Sir Nigel from now on] of the LNER took a great interest in locomotive developments in France. He was on good terms with M. Lancrenon of the Nord and M. Chapelon of the Paris-Orleans. 

The latter caused something of a sensation in 1929 when he rebuilt one of the Paris-Orleans' compound 'Pacifics'. In original form the locomotive was competent but less than efficient. After rebuilding on Chapelon principles, its performance was SimplyStunning. Sir Nigel, like many other locomotive engineers, made the journey to Paris to see the wonderful locomotive and discuss it with M. Chapelon.

Economic conditions meant it wasn't until 1934 the Sir Nigel was able to introduce a new class of locomotive incorporating Chapelon principles. This was the 'P2' 2-8-2 class for the difficult Edinburgh-Aberdeen road. Two engines entered service in 1934, with four more following in 1936.

The first of the class, No. 2001 'male chicken' (changed by forum) o' the North (I fear our Fabulous Forum will have made me look rather foolish) was taken to France for testing, both at the testing plant at Vitry-sur-Seine and on the track between Orleans and Tours. She performed well and Sir Nigel stated publicly that any further members of the class would be modified in the light of what had been learnt from the tests in France.

The Chapelon principle that interests us here is the Kylchap double blastpipe and chimney, fitted to all but one of the 'P2' class. And, yes, the 'chap' refers to M. Chapelon who had modified and developed earlier ideas. And patented his system. This is a sophisticated system, using two blastpipes [M Chapelon's one-off 242A-1 had three blastpipes¹] and precisely-located cowls or nozzles which direct the gasses from the boiler flues out of the chimney. Here's a diagramington, based on the LNER Kylchap arrangement:-




[The Kylchap exhaust seen here consists of a pair of four stacked nozzles, the first is the blastpipe 'A', known as the primary nozzle, which, in the Chapelon design has four triangular jets. That exhausts into the second stage, the 'Kylälä spreader' 'B', which ejects the gasses from the lowest boiler tubes. That then exhausts into the third stage, designed by Chapelon, which ejects the gasses from the middle rows of tubes. Finally, this exhausts into the fourth stage, the chimney cowl. We'll hear a little more about the Kylälä spreader right at the end of this surprisingly brief mini-series.]


The benefit of the Kylchap exhaust is a strong draught, which gives good steaming, and very low back-pressure in the cylinders, giving enhanced power and efficiency. The disadvantage is the need for the precise location of the various components in the smokebox.

As modellers, the contents of the smokebox are of little concern (unless we have a Tri-ang Hornby 'M7' 0-4-4T in H0/00 gauge), but the large double chimney is a distinctive feature of the locomotive's external appearance.

Worth noting in passing is, in 1935, Sir Nigel arranged for the experimental high-pressure 'W1' 4-6-4 No. 10000 to have the same Kylchap arrangement as 'male chicken' (changed by forum) o' the North fitted. No. 10000 retained the Kylchap exhaust after rebuilding as a conventional locomotive in 1937.

In 1935, Sir Nigel's masterpiece, the 'A4' 'Pacific' class, was introduced. With a single blastpipe and chimney. Why the seemingly backward backward step?

In service, the 'P2s' gained a reputation for being heavy on coal, although No. 2001 was not an extravagant engine [OVS Bulleid's terminology] when on test in France. What was going on?

We can blame the Scottish Area operating people. Instead of having the'P2' class working through from Edinburgh to Aberdeen, they stuck to good old North British Railway practices and changed engines at Dundee. This meant they achieved lower daily mileages and spent far too much time hanging around at Edinburgh, Dundee or Aberdeen. Steam engines also burn coal when hanging around doing nothing and the 'P2' class had a 50 sq./ft. grate area.

Unfortunately, there were fears the Kylchap exhaust was contributing to the high coal consumption. So, the 'A4s' had single blastpipes with jumper tops.

Then, in 1937, Sir Nigel arranged for an 'A3' 'Pacific', No.2751 Humorist, to be fitted with a Kylchap exhaust. She performed brilliantly, although the consequent softer blast led to drifting exhaust when working at short cut-offs. She was given small smoke deflectors in 1938, similar to those she had experimentally carried in 1932. These were replaced in 1947 by large deflectors plates like those used on the post-War 'Pacifics'.




[No. 2751 Humorist (what a delightful name for a locomotive) poses for the LNER's photographer after fitting of the Kylchap exhaust but before the addition of smoke deflectors.]


In 1938, four of the final batch of 'A4s' were built with Kylchap exhausts. The Bugatti-inspired wedge front, with a small indentation behind the chimney, meant these had no problems with drifting exhaust. It's always nice to have a list of locomotives, so here they are:

No. 4901 Capercaillie (Sir Charles Newton from 4/6/1943)
No. 4902 Seagull
No. 4903 Peregrine (Lord Faringdon from 24/3/1948 )
and, of course,
No. 4468 Mallard

These four engines were responsible for some wonderful feats of haulage at speed, the most famous of which occurred down Stoke Bank on 3 July 1938. 126 m.p.h downhill with a 40% cut-off! Driver J Duddington, Fireman T Bray and Inspector J Jenkins. A world record - beating a German 4-6-4's 124.5 m.p.h, achieved on 30 May 1936.

It seems that Sir Nigel decided to use the Kylchap exhaust for any future 'Pacifics' to be built but did not commence equipping existing engines with it. PN Townend, of whom we'll hear a lot in the next part, conjectured this was because Sir Nigel was waiting for the patent to expire in 1941.

We'll catch up with post-Gresley LNER 'Pacific' developments in the next part. Let's return to our opening questioningham - 'How many of the 'Big Four' grouped railways used the Kylchap exhaust?'

We know all about the LNER - Mallard's exploits make sure of that, but what about the others?

It's probably safe to rule out the Great Western, but what about the LMS or Southern - did either use the Kylchap system?

The answer is, both did!

We have already noticed the Southern's 'Lord Nelson' class never, at least until after Mr Bulleid's modifications, seemed to live up to expectations. Mr Maunsell arranged for a series of modifications to be made to individual engines in an attempt to improve the breed.  Here's SC Townroe:

'The first really noticeable improvement in performance was observed in 1934 when No. 862 Lord Collingwood was fitted with a Kylchap blastpipe and chimney [...] The device improved draught significantly, at the same time reducing the back-pressure on the exhaust steam. Despite favourable reports from the Locomotive Running Department, this improvement was not followed up immediately.'²

It appears at least two other 'Lord Nelsons' had Kylchap exhausts; one was No. 865 Sir John Hawkins in 1938, seen here in a photograph by the late Rev AC Cawston:-





CJ Allen logged many examples of locomotive performance, including three runs between Surbiton and Basingstoke in the 1937-1939 period. One was behind No. 860 Lord Hawke which he described as being Kylchap-fitted. I have not been able to ascertain if there was more than one Kylchap exhaust, or this is simply due to the boiler and smokebox with this arrangement being exchanged between locomotives during overhaul.

OS Nock was less than impressed by a Kylchap-fitted 'Nelson':-

'In passing, it may be mentioned that a [Kylchap] double blastpipe and chimney had been tried by Maunsell on one of the 'Lord Nelsons', No. 862, Lord Collingwood, but it did not appear to make any difference to the steaming; in fact, that engine in its modified condition contributed to the rather large collection of indifferent runs I personally experienced with the 'Lord Nelson' class engines on the Southern Railway in the last years of the Maunsell regime.'³

More so even than the 'Nelsons', the '5X' or 'Jubilee' class three-cylinder 4-6-0s of the LMS were something of a disappointment at first. And that's a serious understatement. Much tinkering took place over the years, right up to the fitting of a double chimney to No.45596 Bahamas in 1961. This produced an excellent engine as she takes every opportunity to demonstrate out on the main line.

In 1937, the LMS fitted No. 5684 Jutland with a Kylchap exhaust. The result was a significant deterioration in performance. Here's the late ES Cox, who was getting quite senior in the LMS locomotive hierarchy by this time:-

'Improved draughting was one of these. Previous attempts at higher efficiency in this sector had often been unsuccessful, culminating in the volcanic display of a '5X' class 4-6-0 which, when fitted with a double Kylchap arrangement in 1937, had produced a continuous spray of incandescent fuel from the chimney top at anything above the lowest output, the smokebox at the same time filling up with ash to the level of the blastpipe cap during a journey. This was, of course, due to gross unsuitability of the tube proportions, and the lesson was quickly learned that the benefits from more powerful and efficient blast was only fully to be attained by use of a larger number of smaller tubes in the boiler, the end product being increase in evaporative capacity combined with low back pressure in the cylinders.'⁴

Quite!  The Klychap apparatus was swiftly removed.




[The picturingham is from an LMS Official photograph of Jutland after conversion to Klychap exhaust.]


Incidentally, the context in which Mr Cox was writing was last years of the LMS, when Mr Ivatt the Younger was working hard to develop steam locomotives suitable for post-War operating conditions. He was also much involved in the construction of Great Britain's first two main-line diesel locomotives. These were much better than some of the 'Modernisation Plan' efforts that appeared almost ten years later - but there was Government interference aplenty with these. 'Nuff said?

My point is Mr Cox singles out the unfortunate experience with the 'Jubilee', acknowledging it wasn't the fault of the Kylchap exhaust which was, effectively, too good for the engine. He doesn't mention the superb results obtained by the LMS from the '2A' double-chimney boiler retro-fitted to many 4-6-0s or the successful equipping of 'Princess Coronation' 4-6-2s with double chimneys. I have made a similar point before about Mr Cox's writing.

The next part will look at the use of the Kylchap exhaust in the final years of the LNER and under British Railways. It will also discuss another unfortunate consequence of SO Ell's brilliant work at Swindon on draughting.

Better still, it is my hope that the next part will carry this mini-series' tail lamp.

Many thanks to @martyn for reviewing and commenting on the draft text.


¹ 242A-1 entered service in 1946 and was a stunning performer. A three-cylinder compound 4-8-4, she remained a one-off as electrification was seen, in France, as the way ahead. Unforgivably, in my view, she was scrapped in 1960.

² SC Townroe, Arthurs, Nelsons and Schools of the Southern, Ian Allan. London, 1973, Page 54.

³ OS Nock, Sothern Steam, David & Charles, Newton Abbot, 1966, Page 153.

⁴ ES Cox, Chronicles of Steam, Ian Allan, London, 1967, Page 146.


'N' Gauge is Such Fun!

Many thanks for looking and all best wishes.

Toodle-oo

John 

Thanks once again, John @Train Waiting , for the short postingham in this brief mini-series.

For those who may want to find out a little more about exhaust design, there are a number of search results in Google, but this link has a short summary of those generally referred to by John, and some more recent ones which won't be covered in this series;

http://www.trainweb.org/tusp/ex_dwgs.html

One problem with fitting smokebox devices was that they often rendered the cleaning of the boiler tubes difficult, as they were 'swept' with a brush on a very long rod, rather like a drain cleaning rod; sometimes, it was necessary to remove part of the exhausts to get to some tubes. The Giesl exhaust was good in this respect, as the thin shape (viewed end on) gave easy access to just about all the boiler tubes. They sometimes also precluded the ability to fit 'self cleaning' smokeboxes, as there wasn't enough space for the cleaning grids. I'll let you do your own research on these, but it was one reason why the V2s had steaming problems, as these grids interrupted the flow of the hot gases through the smokebox and had an effect on the draft on the fire. I'll add a bit more when John has written up about the V2s.

Referring to the P2s, the Aberdeen 'road' was a tough one due to its sinuous nature for such a long wheelbase loco. This meant wear on the crank axle was magnified with the high piston loads, and there were failures of the axles in traffic. These failures prompted Mr. Thompson to rebuild the locos as Pacifics; enthusiasts of the time, and also since, have questioned that, as this was during WW2, why the locos weren't just transferred to the easier, straighter, lines of the ECML between King's Cross and Newcastle. Wartime loads were frequently very heavy, and the extra power would presumably have been much appreciated by the loco crews. (Incidentally, a D16/3 'Claud', the former Royal engine 8787, once took an hour to do the 29 miles between Peterborough and Grantham, up Stoke bank; there was 'plenty of steam, it just wouldn't go faster' The load was 17 bogie coaches, a 'normal' wartime load. Twenty plus was not unknown).

If a P2 failed, or after they were transferred, Shedmasters had the sometimes difficult task of finding two replacement locos (to double head) and a second crew. Pacifics were not permitted to be double headed on the Aberdeen run.

Until the next one, John.

Martyn

What a brilliant series, many congrats John!
I've often tried to understand the Kylchap exhaust system, and never really got to grips with it - now I think I have, thanks to your series.
Looking forward to the next parts.
Cheers! 

Going just slightly  but it is related to P2 2001's trip to France for testing.

By coincidence, my local historical society has published a letter this month concerning the outward trip of the loco. Naturally enough, the loco arrived at Parkeston shed, the nearest one to the ferry (about a mile away, you could see it from the ship) chimney first. However, for whatever reason, the ship required the loco tender first on the ship, which meant turning the loco before loading. However, the Parkeston shed turntable was too small.....

No problem, the Harwich branch had, and still has, north and south facing junctions with the main line.

So the letter tells how the loco was reversed along the branch to Manningtree, about ten miles, turned on the triangle, and then worked tender first back to Parkeston shed and then finally to the ship.

The loco took with it a wagon full of spares, and three 40T bogie coal wagons filled with coal, plus brake van. It worked to Parkeston via the Cambridge main line to north London, and then back down the Colchester line to the Harwich branch, as it was too heavy to go via Bury St Edmunds and Ipswich. A similar route was taken when 10000 was exhibited at Ipswich.

Hope the short trip working has been of use.

Back on topic, as part of the trials in the UK, a number of different arrangements of the Kylchap exhaust were tried out, involving changes to the blastpipe top, taper blocks and cowls before an acceptable solution was found. Chapelon thought that this was rather different from his findings in France, but on testing in France, after once again using  a variety of settings and sizes, the UK solution, with some small adjustments, was found to be probably best overall, and that's how the engine was set when it returned to the UK. Before leaving France it was exhibited in Paris alongside a Nord 'Super Pacific' and a brand new Maybach diesel electric streamlined train.

Martyn

 

A Coarse Guide to the Steam Locomotive for 'N' Gauge Modellers - Part 103


Hello Chums

The Final, Exhausting Section of Our Gloriously Brief Mini-Series

'Multiple Jets - Kylchap'

"Undo four nuts and make a bigger hole in the top of the smokebox and you are there."

Arthur Taylor, Chargehand Fitter, King's Cross MPD 'Top Shed'.

Sir Nigel Gresley died in 1941 and was succeeded by Edward Thompson. We'll leap gazelle-like over the controversies of Mr Thomson's time and simply note that he fitted Kylchap exhausts to his 'Pacific' rebuilds, classes 'A1/1' 'A2/1' and 'A2/2'.

He also fitted his new 'Pacifics', class 'A2/3', with the Kylchap exhaust.

Mr Thomson retired in 1946 and was succeeded by Arthur Peppercorn. It's fair to say that many of the staff of the locomotive department, including in the Drawing Office, had an uneasy relationship with Mr Thompson and found Mr Peppercorn a much more agreeable chief. They were keen to put the Thompson years behind them and remove as many idiosyncratic Thompson features as they could from any further 'Pacifics' to be built.

Which sort of explains the story that went round that the Peppercorn 'A2' 'Pacific' class were fitted with single chimneys as a reaction against Mr Thompson's use of the Kylchap exhaust. Incidentally, 'P2' 2-8-2 No. 2005 Thane of Fife had a single blastpipe and chimney, but when Mr Thompson rebuilt her as an 'A2/2' she was given a Kylchap exhaust like the rest of the class.

There were 15 Peppercorn 'A2' 'Pacifics', entering traffic from December 1947 to August 1948. The last one, No. 60539 Bronzino (splendid name!), was fitted with a Kylchap double blastpipe and chimney. It had been noticed that the locomotives fitted with a single chimney were not quite as good as had been expected. Bronzino was a fine engine and it was arranged to fit five others with the Kylchap exhaust during 1949. Which gives an opportunity to have another list of engines. The five were:

60526 Sugar Palm
60529 Pearl Diver
60532 Blue Peter
60533 Happy Knight
60538 Velocity

Given that the double-chimney 'A2s' were better engines, I wonder why they were not all converted. Maybe someone will be able to enlighten us in the discussion.

Also, the double-chimney engines were dispersed across the E, NE and Sc regions, from Ferryhill (Aberdeen) to King's Cross. One would have thought it would have been good to concentrate them where they could be most effective; the difficult Edinburgh to Aberdeen line being an example.




['A2' 'Pacific' No. 525 AH Peppercorn new at Doncaster Works on 31 December, the last day of the LNER. Mr Peppercorn and some of his staff pose beside the locomotive.]


The lesson regarding the Kylchap exhaust had been well-learnt and all of the Peppercorn 'A1' class, entering traffic between August 1948 and December 1949 were fitted with it from new.

***

But what about the Gresley 'Pacifics'?

By the end of 1948, three out of the four Kylchap-equipped 'A4s' were allocated to 34A King's Cross 'Top Shed'. The fourth, No. 60005 Sir Charles Newton was at Gateshead. At Top Shed, the three Kylchap-equipped 'A4s' were recognised as being superior performers to the single-chimney locomotives. As efforts were made to gradually restore train services to something like pre-War standards, the limitations resulting from the conditions prevailing in the late 'forties and early' fifties became apparent. These were difficult years in Great Britain.

The steaming of the single-chimney 'A4s' was beginning to give cause for concern. The Kylchap-fitted engines would steam freely without the skill and attention of the enginemen required by the single-chimney locomotives. It was becoming difficult to recruit new staff of the calibre required and many of the most experienced enginemen and shed staff had retired or were about to do so.

Monopolies, especially state monopolies, are rarely conducive to customer choice and nationalisation of the coal industry meant that the railways were much less able to specify coal from particular collieries. There was also a massive export drive in progress to try to repair the country's finances, which led to much of the best coal going for a sail on a ship.

A combination of some less experienced enginemen and shed staff, and poorer coal did not agree with the single-chimney 'A4s', or 'A3s' for that matter.

A feature of BR, when under the centralised control of the Railway Executive, was movement of senior officers between regions. Which led to KJ Cook, a GWR then WR man, becoming Chief Mechanical Engineer of the ER and NER in 1951. He brought many good Swindon practices with him, such as optical alignment of the frames and axleboxes.

However, he was resistant to requests to fit the single-chimney 'A4s' with Kylchap exhausts, firmly believing that the Swindon proportions, perfected by Sam Ell and his team, was all that was required. From 1953, something of a tug-of-war commenced. The CME experimented with variations of the Swindon proportions whilst Top Shed illicitly tampered with the blastpipes in an effort to improve matters.

Meanwhile, senior ER locomotive men such as LP Parker, Motive Power Superintendent, Eastern Region,¹  CN Morris, Divisional Maintenance Engineer at King's Cross and PN Townend, Shedmaster at King's Cross, were pressing the CME to simply fit Kylchap exhausts. The pressure seems to have further entrenched Mr Cook's position and he maintained a, for me, impossible to understand opposition to the Kylchap system. There was even a suggestion that the Klychap exhausts might be removed from engines fitted with it!

By 1957, the single-chimney 'A4s' blastpipes had been reduced to 5 1/8 in. diameter. This resulted in a lot more noise and less efficiency. Efficiency can be seen in coal consumption and the 'A4s' were the only engines which worked the 'Non-Stop' 'Capitals Limited' - the 'Elizabethan' from 1953. Having sufficient coal to complete the journey was essential and coal consumption was a critical factor.

Interestingly, the solution came from Sir Winston Churchill's Conservative Government and its Transport Act, 1953. This disbanded the Railway Executive and devolved a lot of responsibility to the Regions, which now reported direct to the British Transport Commission. The Regional General Managers were given significantly more power, including an organisational line to the motive power depots.

King's Cross did a series of tests and calculated the saving in coal per mile of the Kylchap engines was 6-7 lbs which would quickly pay for the conversion to Klychap exhausts.

The CME maintained that the conversion would be expensive. Before the War, Kylchap apparatus had cost £400-£500. The patent had expired in 1941 and it would now cost around £200 for an 'A4' and £153 for an 'A3'. Regarding the difficulties posed by the installation, it had been suggested a new inside cylinder casting would be required. To test if this was true, Mr Townend instructed Arthur Taylor to measure up everything inside the smokeboxes of a Kylchap and single-chimney 'A4' and report what would be required to change a single blastpipe locomotive to a Kylchap.

Mr Taylor's conclusion was priceless and made a splendid introduction to this part.

The CME had been outmanoeuvred and the General Manager was keen to see his cost savings.  No. 60017 Siver Fox emerged from Doncaster in May 1957 with a Kylchap exhaust. She had been a very good engine but had lately developed a reputation of being a shy steamer. She was transformed and was now a superb locomotive. All of the class were converted by November 1958. As far as I can ascertain, the last to be converted was No. 60032 Gannet, which emerged from Doncaster Works on 27 November 1958.

As we saw, the 'Swindon' dimensions used on single-chimney engines by 1957 resulted in a single 5 1/8 in. diameter blastpipe. Lots 'N' lots of noise, high back pressure and, unfortunately, potentially dodgy steaming on post-War coal. The Kylchap exhaust fitted to the 'A4s'had two blastpipe tops of 5 in. diameter - much better. 




[Sir Nigel Gresley, as converted with a Kylchap exhaust in December 1957. The Minitrix model depicts her in preserved condition as, of course, she didn't have a double chimney in LNER days.] 


After authority had been given to convert the 'A4s', Mr Townend and his colleagues conducted coal saving tests on 'A3s'. This was a little less than for 'A4s', at 6 lbs per mile, but still made the Kylchap conversion viable. Commencing with No. 60055 Woolwinder in June 1958, the conversion of the 'A3s' was complete by the end of 1959. The transformation of the 'A3s' was remarkable and was proof, if any were really needed, of the excellence of the Kylchap exhaust.

But the SuperSmelly diesels were coming. This led to an interesting development. The 'V2' 2-6-2s, like all Gresley engines, were good steamers but the fitting of spark arrestors in their smokeboxes under BR had caused steaming and performance to decline. The diesels were entering service and failing. Which meant the Peterborough standing pilot was kept busy. And Peterborough's turntable couldn't take a 'Pacific'; the biggest engine it could manage was a 'V2'.

After a straightforward double chimney was fitted to No. 60817, to no special advantage, common sense took over and six 'V2s' were fitted with Kylchap exhausts. They were exceedingly good engines - a couple were at Peterborough for standing pilot duty and 'Top Shed' made good use of the others, especially on fast freights to York. They saw some passenger work as well and an Inspector riding on No. 60881 had to instruct the driver to close the regulator due to the speed at which the train was travelling. 95 mph!

For details on the conversion of the Gresley locomotives to Kylchap exhausts, I have relied heavily on the writings of the late PN Townend, without whose tenacity I doubt whether it would have been achieved. I have included two valuable sources in the footnotes at ² and ³.

**

So ended steam locomotive development for main line railways in Great Britain. As I mentioned before, the air-gas-steam-exhaust circuit was, I believe, the last piece of unfinished business. We have seen various, and sometimes contradictory, developments in the BR era, right up to 1962. Several locomotive engineers furth of Great Britain continued development, but that is beyond the scope of this mini-series.

Let's return to the Kylchap exhaust. As I mentioned earlier, the 'chap' part of the name came from M. André Chapelon, who developed an earlier system, primarily by adding a third stage nozzle or cowl. We noted the second stage is the Kylälä spreader, which was a vital component of the earlier system. Hence the 'Kyl' part of the name.

The earlier system was the creation of a Finnish engineer, Kyösti Kylälä.

I told you we'd Finnish with a Finn!

FINIS


¹ LP Parker was a remarkable railwayman. The late Mr Hardy has written of him with great respect and affection. He retired in 1955 and died a year later, so didn't see the transformation of the Gresley 'Pacifics' by the fitting of the Kylchap exhaust that he had worked hard to bring about.

² PN Townend, Top Shed, Ian Allan, Shepperton, 1975. Mr Taylor's quote is on page 148.

³ PN Townend, East Coast Pacifics at Work, Ian Allan, Shepperton, 1982.

**

As we've reached the end of this staggeringly brief mini-series, I'd like to conclude with acknowledgements and thanks. I wrote it primarily for entertainment, thank you to those kind people who mentioned they found it informative.

@Bealman , @Nbodger and @port perran kindly provided photographs - thank you.

@martyn , @Hailstone and Ted were of enormous help in commenting on drafts and suggesting improvements. Without their kind and patient assistance, the mini-series would have been much less accurate - my profound thanks to all three.

Any remaining errors, omissions and embarrassments are entirely my responsibility.

@Tank must spend lots 'N' lots of time and money on our FabulousForum which gave me a welcoming place to write about steam locomotives from a modeller's perspective. Thank you.

Thank you to everyone who contributed to the discussion or left encouraging 'reactions'.


'N' Gauge is Such Fun!

Many thanks for looking and all best wishes.

Cheerie-bye

John

Well there you go.
What a fabulous series of postingtons from which I have learned so very much about steam locomotives.
Thank you so much John @Train Waiting and everyone else who has contributed.

PS By coincidence this month's copy of Heritage Railway magazine mentions that 71000 Duke of Gloucester was originally to have been fitted with a Kylchap double blastpipe but this never happened until one was retro fitted by the Great Central Railway.

Thanks again John
Best Regards
Martin

Just wunnerful, John
 

Thank you, John for a truly wonderful series which, despite its extreme brevity, taught me a great deal. It is also considerably more lucid than a lot of professionally produced works of this kind.

Thanks again and all the best,

Ali

Ahhh, what now John, an excellent series so what will the sequel be?

Tim

So... Is that the lot???

This "little" series has been absolutely brilliant, and has woken up my totally non-technical artistically trained mind to some vague understanding of a subject that has been a closed book to me for the past 60 years. Thank you for that.

Have you considered the publication of this "little" series in book form? As you have so often called it a "mini series", it would be a very slender volume indeed..!

However, I was hoping that the work of Sam Ell at Swindon, and the fitting of double chimneys to all of the "Kings" and many of the "Castles", would feature within your excellent "mini series"... But this is not a whinge.

Again thanks to you, and your "back-up" team, on a super job, very well done!

Quote from: Moonglum on Yesterday at 05:42:49 PMAhhh, what now John, an excellent series so what will the sequel be?

Tim

No doubt those dirty, smelly diesels   

A tear springs unbidden to the eye...

I've felt the need at various points in this concise treatise to add a word of thanks, but this is the moment to expand the word into a full sentence. Thank you! The BBC remit is to Educate, Inform and Entertain, and you have done all three. Now that you have concluded, my poor overworked brain cell can go back to sleep, at least until your next project. What's it to be, John? Rolling Stock? Track and Infrastructure? Signalling?

In all seriousness, John, this exceptionally brief series has been an absolute eye-opener and I can't thank you enough for all the diligent research and hard work you have put into it, especially at the times when you haven't been in the best of health. I agree with others when they say there is the core of a very fine book here but you may feel that is too much hassle.

Whatever you decide, you have earned a few days with your feet up and a dram in hand.

With very best wishes,

Chris

I had a little more to add about the use of Kylchap chimneys on the LNER/ER, but John has more or less covered my material.

I think the subject has been extremely well explained.

Thank you for the thread, and I hope my additions have also added to the information.

Congratulations.

Martyn