High pressure locomotive

High-pressure locomotive SLM Eb 3/5 with a boiler pressure of 60 bar

High- pressure locomotives , also called high-pressure steam locomotives , are steam locomotives that were operated with a boiler pressure of over 25 bar. Of this special design, 24 locomotives were built between 1925 and 1954 worldwide for test purposes. The complicated technology promised better efficiency, but was only developed slowly because of the Great Depression and the Second World War , until it was overtaken by the introduction of electric and diesel locomotives .

technology

Locomotives with classic steam locomotive boilers according to Stephenson have technical and economic limits because the boiler pressure cannot be increased above 21 bar without disadvantages. Because as the boiler pressure increases, so do the demands on the boiler building material, so that manufacturing and maintenance costs rise. The overall efficiency of such a locomotive is 10%. It was known from ship steam engines and stationary systems that higher steam pressures save both fuel and water. In addition, smaller cylinders can be used and the steam can be expanded not only in two, but also in three stages, as in the case of conventional composite steam locomotives . However, these advantages had to be bought at the cost of a different type of boiler, the water tube boiler , which was more complicated in construction than the Stephenson boiler and had not yet proven itself in rail operations. In addition, an induced draft system usually had to be used to fan the combustion.

Boiler types

Schmidt-Henschel boiler

Longitudinal section of the Schmidt-Henschel boiler of the PLM 241 B 1

The two-pressure boiler or Schmidt-Hartmann boiler developed by the Schmidtsche Superheated Steam Company consists of a closed high-pressure circuit that heats an open low-pressure circuit via a heat exchanger. The evaporation thus takes place outside the furnace, where the pipes are not directly exposed to the radiant heat. This prevented unclean water from forming scale in the pipes. The only deposits were on the outside of the tubes of the primary circuit in the evaporator drum, where they were easy to clean. The primary circuit was filled with purified water so that no deposits could arise there.

In collaboration with Henschel, the Schmidt boiler was adapted for installation in locomotives. The primary circuit of the Schmidt boiler had the highest pressure of 95 bar, the high-pressure steam generated in the secondary circuit had a pressure of 60 bar. Preheater and heating pipes of the primary circuit formed the walls of the fire box . This was followed by a conventional long boiler in which superheated steam was generated at a pressure of 17 bar. The steam from the Schmidt boiler was fed to the individual high-pressure cylinder in the frame. The exhaust steam from this cylinder got into the two outer low-pressure cylinders together with live steam from the long boiler.

Several locomotives were equipped according to the Schmidt-Henschel system, including the H 17 206 . The locomotive was used on test drives with a measuring car. A theoretical fuel saving of 47 percent was hoped for. However, the actual values ​​were much lower and did not justify the high development costs. In addition, there were safety concerns due to the high steam pressure when driving. The necessary maintenance work and the associated costs were not clarified.

Mill field water tube fire tube boiler

Muhlfeld boiler on the Delaware and Hudson Railway locomotive No. 1400

The German-born engineer John Erhardt Mühlfeld designed a boiler that consisted of a water pipe fire-gun and an adjoining Stephenson long boiler. On both long sides of the fire box, drums were attached above and below, in which the side tube walls of the fire box ended. The upper drums formed the steam chamber of the boiler and were extended forward beyond the fire box.

Winterthur boiler

The boiler developed by the Swiss Locomotive and Machine Works in Winterthur , also known as the SLM water tube boiler , consisted of a fire box with water tube side walls and roof and water-filled double walls on the front and back. At the bottom of the fire box, two drums were attached along the length to hold the pipes, and in the middle above the fire box an upper drum was arranged as a steam collector. The combustion air was not sucked in through the ash box as usual , but instead entered the two air preheaters through two openings in the front of the smoke chamber and was directed along the boiler to the fire box. The feed water was pressed through an exhaust steam and a flue gas preheater into the upper drum of the boiler. It almost reached the evaporation temperature when it entered the boiler. This prevented the scale from forming in the tubular boiler, which is difficult to clean, but from depositing in the two preheaters that were optimized for cleaning. The SLM boiler had a high power density thanks to the thermally optimized utilization of the flue gases. The heat of the flue gases was used by the front double wall of the fire box to evaporate the water in the boiler, the superheater, the feed water preheater and the combustion air preheater in the smoke chamber.

Executed locomotives

The technology of the high-pressure steam locomotive was tested in Germany , Great Britain , France , Switzerland , Canada and the USA .

The implemented locomotives can be divided into four groups according to the technology used:

1. Locomotives with pure water tube boilers
2. Locomotives with a water pipe fire box and a classic long boiler
3. Locomotives with two-pressure boilers according to Schmidt-Hartmann , where a closed primary steam circuit generates process steam in a heat exchanger
4. Locomotives with forced circulation boilers

Germany

In Germany , three attempts with high-pressure locomotives are known; These are the H 17 206 (version according to group 3), the H 02 1001 (version according to group 4 with Löffler kettle ) and the H 45 024 (version according to group 4 with Velox kettle ). All locomotives did not get beyond the test status.

Switzerland

In Switzerland, the Schweizerische Lokomotiv- und Maschinenfabrik manufactured a locomotive with a tubular boiler and 60 atm boiler pressure in 1927 . This type Eb 3/5 tank locomotive was extensively tested between 1928 and 1931 and, compared to the SBB B 3/4 superheated steam passenger locomotive, saved up to 50 percent water and up to 40 percent less coal. This remained a test locomotive.

Table of all executed high-pressure locomotives

country	train	model series	number	boiler	pressure	Construction year	Manufacturer	design type	execution	group	image
UK	LNER	Class w	10,000	Yarrow cauldron with 5 drums	31 bar	1929	Darlington Works	2'C11 'h4v + 4	Piston steam locomotive	1
United States	D&H		1400 Horatio Allen A)	Mühlfeld boiler	28 bar	1924	Alco	1'D h2v	Piston steam locomotive	2
United States	D&H		1401 John B. Jervis B)	Mühlfeld boiler	28 bar	1927	Alco	1'D h2v	Piston steam locomotive	2
United States	D&H		1402 James Archibald C)	Mühlfeld boiler	34 bar	1930	Alco	1'D h2v	Piston steam locomotive	2
United States	D&H		1403 LF Loree D)	Mühlfeld boiler	35 bar	1933	Alco	2'D h4v	Piston steam locomotive	2
United States	NYC	HS-1a	800	Schmidt-Henschel boiler	108 bar	1931	Alco	2'D2 'h3v + 3	Piston steam locomotive	3
UK	LMS		6399 Fury	Schmidt-Henschel boiler	110 bar	1929	North British	2'D h3v	Piston steam locomotive	3
Canada	CPR	T4a	8000	Schmidt-Henschel boiler	93 bar	1930	CPR Angus Shop	1'E2 'h3v + 3'3'	Piston steam locomotive	3
France	PLM	241 B	1	Schmidt-Henschel boiler	108 bar	1929	Henschel	2'D1 'h4v + 2'2'	Piston steam locomotive	3
Germany	DRG	H 17	206	Schmidt-Henschel boiler	90 bar	1925	Henschel	2'C h3v	Piston steam locomotive	2
Germany	DRG	H 02	1001	Löffler kettle	120 bar	1945	Schwartzkopff	2'C1 'h3v + 2'2'	Piston steam locomotive	4th
Switzerland	SLM	Eb 3/5	no	Winterthur boiler	60 bar	1927	SLM	1'C1 'h3	Steam engine	1
France	SNCF	232 P	1	Winterthur boiler	60 bar	1936	SACM Fives-Lille cutter SLM	2'Co2 'h18 + 2'2'	Steam engine	1
Germany	LBE	I.	DM 22	Doble kettle	120 bar	1934	Henschel	B.	Shunter	4th
UK	LMS		7192	Doble kettle	unknown	1934	Sentinel	B.	Shunter	4th
France	PLM	230 E	93	Velox boiler	20 bar	1937	CEM	2'C h4v + 3	Piston steam locomotive	4th
Russia	RZD	В5	01	Ramsin cauldron	80 bar	1937	Kolomna	Bo'2 '	Steam engine	4th
Germany	DR	H 45	024	La Mont cauldron	42 bar	1951	VEB Lokomotivbau Karl Marx Babelsberg VEB Meeraner steam boiler construction	1'E1 'h3v + 2'2'	Piston steam locomotive	4th
Colombia	FCN		(3 pieces)	Woolnough cauldron	38.5	1933	Sentinel	Co'Co 'h12v	Steam engine	1

Explanation of the names of the D&H locomotives:

^A. Horatio Allen : Chief Engineer of D&H who imported the first locomotive on the railway, the Stourbridge Lion, from England

^B. John B Jervis : D & H's first chief engineer who designed rail operations. Engineer of the first steam locomotive built in the USA

^C. James Archibald : D & H's chief engineer in the 1830s

^D. LF Loree : President of D&H from 1907 to 1938

literature

• Wolfgang Stoffels: Locomotive construction and steam technology: Tests and results with high pressure steam locomotives, steam engine locomotives, steam turbine locomotives . Springer-Verlag, 2013, ISBN 978-3-0348-5877-9 ( books.google.com ).
• Hans-Dieter Häuber, Dierk Lawrenz: Schwartzkopff locomotives 1867-1945 , Steiger-Verlag Moers, ISBN 3-921564-75-1 .

Individual evidence

1. ^ Wolfgang Stoffels: Lokomotivbau und Dampftechnik: Tests and results with high pressure steam locomotives, steam engine locomotives, steam turbine locomotives. Pp. 37-38.
2. ^ P. Ransome-Wallis: Illustrated Encyclopedia of World Railway Locomotives . Courier Corporation, 2013, ISBN 978-0-486-14276-0 , Steam locomotives using very high pressure, pp. 464 (English, google.com [accessed October 14, 2018]).
3. ↑ Railway teaching library of the Deutsche Bundesbahn Volume 134 Steam Locomotive Knowledge 2nd revised edition 1959 2nd reprint 1983 page 287
4. ↑ Stoffel, p. 25
5. ^ P. Ransome-Wallis: Illustrated Encyclopedia of World Railway Locomotives . Courier Corporation, 2013, ISBN 978-0-486-14276-0 , Steam locomotives using very high pressure, pp. 464 (English, google.com [accessed October 14, 2018]).
6. ^ Wolfgang Stoffels: Lokomotivbau und Dampftechnik: Tests and results with high pressure steam locomotives, steam engine locomotives, steam turbine locomotives. Pp. 71-72.
7. ^ Wolfgang Stoffels: Lokomotivbau und Dampftechnik: Tests and results with high pressure steam locomotives, steam engine locomotives, steam turbine locomotives. Pp. 47-48.
8. ^ P. Ransome-Wallis: Illustrated Encyclopedia of World Railway Locomotives . Courier Corporation, 2013, ISBN 978-0-486-14276-0 , Steam locomotives using very high pressure, pp. 464 (English, play.google.com [accessed October 14, 2018]).
9. ^ Alfred Moser The steam operation of the Swiss Railways 1847–1966 4th edition, pp. 266–267
10. ↑ Schweizerische Bauzeitung Volume 91 (1928), Issue 22, p. 265 e-periodica.ch and Volume 97 (1931), Issue 24, p. 297 e-periodica.ch