There were several reasons for strange chimney designs. Here are some:
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- SMOKE DISPERSAL To disperse smoke & steam which obscured the driver's view.
- THERMAL EFFICIENCY To increase efficiency by extracting more heat from the combustion gases.
- STEALTH To make the locomotive exhaust less conspicuous- the Stealth Steam-engine.
- SPARK CONTROL To control the emission of sparks and cinders.
- FOR REASONS UNKNOWN Sometimes it is hard to guess what the designer was aiming at.
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SMOKE DISPERSAL
Left: Square chimneys like this were unique to Belgian locomotives.
The flat chimney front (which would not have caused that much air resistance at the modest speeds of these locos) was designed to clear smoke from the boiler to improve visibility. The front lip at the top of the chimney, known as a visière or "visor" was supposed to improve the draught.
This is a type 25 locomotive built in 1895 by the maker Franco-Belge. Photo date unknown.
Square chimneys were fitted in the period 1884 - 98.
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SMOKE DISPERSAL
Left: Scottish louvred chimneys
This design, intended once again to lift the smoke clear of the boiler, was typical of Highland Railway practice in the 1890's.
It did not work.
When No 14393 Loch Laoghal was photographed it was owned by the LMS Northern Division.
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SMOKE DISPERSAL
Left: Prussian S3 No 237 with two "stove pipes" either side of the steam dome.
This modification followed complaints from the crew about smoke obscuration.
This photo appears to have been retouched in a less than subtle manner, hence the black background. Even in well-regulated Prussia, it would be hard to get the coal in the tender quite that flat...
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Above: Prussian S3 No 237 again, showing more clearly that there were two "stove pipes", running each side of the steam dome.
Presumably this arrangement did not help the draught, for there appears to be some sort of valvebox over the normal chimney position that would allow the exhaust to be sent straight out in the usual way when maximum steam generation was needed. A horizontal control rod appears to lead back to the cab.
Since locomotive aesthetics seem to matter, the stove-pipe solution did not find favour. R P Wagner's deflector plates were preferred.
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SMOKE DISPERSAL
Left: A Hungarian MAV328 501 with special chimney: 1920
The idea being, no doubt, that air would enter the openings at the front of the cowl and be deflected to blow the chimney smoke upwards. The 2C h2 locomotive was built by Henschel of Germany; the MAV number indicates that the locomotive operated in Hungary.
No further facts known, but it looks as though the amount of air that would be so deflected would be completely inadequate for the job.
From Dampflokomotiven und ihre Bauteile by Franz P Flury
ie Steam locomotives and their Components
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SMOKE DISPERSAL
Left: A German DR57 with special chimney: 1910
It's not wholly clear what is going on here, but the pipes running into the chimney make me suspect that steam jets were intended to raise the smoke clear of the boiler; presumably it was only intended for occasional use, such as when dealing with adverse wind directions, or a lot of steam would have been wasted. Anybody know anything about this?
From Dampflokomotiven und ihre Bauteile by Franz P Flury
ie Steam locomotives and their Components
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SMOKE DISPERSAL
Left: A German DR01 with a ramp deflector behind the chimney: 1926
Locomotive built by AEG.
From Dampflokomotiven und ihre Bauteile by Franz P Flury
ie Steam locomotives and their Components
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SMOKE DISPERSAL
Left: A German DR43 with air-deflecting ramp in front of the chimney: 1928
Locomotive built by Schwarzkopf.
From Dampflokomotiven und ihre Bauteile by Franz P Flury
ie Steam locomotives and their Components
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SMOKE DISPERSAL
Left: A Norwegian C27 with vertical deflectors each side of the chimney: 1912
This reminds me irresistibly of an alarmed Dogbert.
Locomotive built by Thunes. (?)
From Dampflokomotiven und ihre Bauteile by Franz P Flury
ie Steam locomotives and their Components
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Left: This engine, with its exceedingly lofty chimney, is the Anglet, built by Anatole Mallet in 1876.
The Bayonne-Anglet-Biarritz line in France used double-decker coaches, and so a very tall chimney was required to lift the smoke clear of the upper deck. The Anglet was the first French compound locomotive.
This photo was taken at Bayonne, home of the Bayonet.
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Left: Another view of Anatole Mallet's compound.
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THERMAL EFFICIENCY
Left: The "double-chimney" locomotives of Joseph Beattie. LSWR, 1855
This design was a fast goods engine for the London & South Western Railway, designed and built by Joseph Beattie at Nine Elms in London. They were the first engines to use coal- rather than coke- on the LSWR.
What appears to be a small secondary chimney in front was actually a vertical jet condenser that formed part of Beattie's first type of feedwater heating apparatus.
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Beattie produced a number of engines with feedheaters, and it is not known which of them is portrayed above. No 135 "Canute" had a single feedheater column, while No 167 "Atalanta" had two, disposed symmetrically in front of the actual chimney. The column technology was later replaced by more conventional heat exchangers at the side of the boiler. These engines were reputed to have the highest thermal efficiency of any in the country, though on what tests this claim was based is obscure.
Joseph Hamilton Beattie, (1808-71) was Locomotive Superintendant of the LSWR from 1850 to 1871.
Above: Detail from a painting by Cuthbert Hamilton Ellis of Beattie's locomotives at Nine Elms depot.
The "Medusa" at the front has one extra "chimney" that is really a feedheater, but the unnamed locomotive behind it appears to have two columns in front of the real chimney. Note extra pipework at the sides of the smokeboxes.
For more information, see: The Beattie Feed-Heater Locomotives
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THERMAL EFFICIENCY
Left: M Petiet of the Nord strikes again. 186?
A duplex-drive locomotive on the French Nord network. The hot gases passed through the boiler tubes as usual and then turned back to pass through the steam-dryer on top of the boiler.
For some reason I always think of elephants when examining Petiet's designs.
For more strange chimneys prompted by a desire for thermal efficiency, see also: Petiet's Experiment and Franco-Crosti Boilers.
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STEALTH
Left: Chinese stealth chimney
This is an armoured train used by the Chinese army, photographed near Ho-Nan. Photo date unknown. The chimney has been redirected to ground level in an attempt to dissipate the smoke and make the approach of the train less obvious.
The dustbin-like thing at the left is a rotating machine-gun turret.
See also Polish armoured trains, some of which had similiar stealth chimneys. Others had even stranger versions... see below.
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STEALTH
Left: The locomotive of the Polish armoured train "Saper"
A kkStB series 97 locomotive armoured in late 1918 by the Zieleniewski factory in Cracov. This locomotive was used in 1919 as part of the Polish armoured train P.P.17 "Saper".
The chimney opening seems to be facing forwards, which not have helped the draught. Unless the loco was designed to normally travel backwards?
Reproduced, by permission, from Michal Derela's superb armoured-train website:
http://derela.republika.pl/armtrain.htm
Do not miss!
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Left: Triple stealth chimneys
This was a stealth experiment by Bullied; the idea was to disperse the exhaust quickly to make the train less visible to enemy aircraft. There was no significant improvement and it was quickly removed.
The loco is 4-6-0 No 783 Sir Gillimere of the "King Arthur" class, on the Southern Railway in Great Britain.
Photographed in the mid 1930's.
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SPARK SUPPRESSION.
Above: The Adler locomotive of 1854 had a conventional chimney- unconventionally placed halfway along the boiler.
The Adler was one of the Eagle Class on the Baden State Railway, one of the pre-unification German state railways. It is a Crampton locomotive; ie it has a single pair of drivers at the rear. This was a popular configuration in Europe until heavier trains made its lack of adhesive weight too obvious.
The Adler had what was called a 're-entrant smokebox'. The firetubes ran to the front of the boiler as usual, but the combustion gases then doubled back over the top of the boiler to the base of the chimney. This apparently gave good spark-suppression at the expense of good steaming.
The Crampton layout, with the driving axle at the rear, allowed the cylinders to be halfway along the boiler and therefore conveniently placed for directing the exhaust up the chimney in the usual way.
