The steam locomotive exhaust system consists of those parts of a steam locomotive which together discharge exhaust steam from the cylinders in order to increase the draught through the fire. It usually consists of the blastpipe (or first stage nozzle), smokebox , and chimney , although later designs also include second and third stage nozzles.
31-509: A Kylpor ejector is a type of steam locomotive exhaust system developed by noted Argentine locomotive engineer Livio Dante Porta . In a steam locomotive , draft is produced in the firebox by exhausting the steam coming from the cylinders out the chimney. The Kylpor exhaust delivers improved draughting capacity over traditional exhaust systems, and is a later development of the Kylchap exhaust. This rail-transport related article
62-496: A result of this, three further series of Pacifics were similarly modified. This was followed by a more comprehensive rebuild of Pacific 4521 as a 4-8-0 , which was completed in August 1932. The success of that work led to eleven more rebuilds to locomotives numbered 4701-4712 (later 240 701 - 240 712). Those locomotives produced almost 40 indicated horsepower (ihp) continuous per metric ton locomotive weight, which probably still
93-402: A triple Kylchap exhaust, double high-pressure valves and Willoteaux valves on the low-pressure cylinders. Completed in 1946, and with a continuous power output of 5500 ihp, the locomotive was rather more powerful than contemporary French electric locomotives, resulting in a hasty redesign of subsequent electric locos, increasing their power by another 1,000 horsepower (750 kW). However,
124-655: A visit to the American Locomotive Company (ALCO) works in Schenectady, New York , and after experience with the operating characteristics of 242A1 became known. They were planned to be 3-cylinder Sauvage compound locomotives , with a large, 6m (65 sq. ft) grate area, for duties that required high horsepower, and were to be complemented by 2-cylinder simple expansion 2-8-0 and 2-10-0 designs for less-demanding duties. The 152 ( 2-10-4 ) locomotive design had two frames partially constructed, before
155-420: Is a stub . You can help Misplaced Pages by expanding it . Steam locomotive exhaust system The primacy of discovery of the effect of directing the exhaust steam up the chimney as a means of providing draft through the fire is the matter of some controversy, Ahrons (1927) devoting significant attention to this matter. The exhaust from the cylinders on the first steam locomotive – built by Richard Trevithick –
186-403: Is a device that releases steam directly into the smokebox for use when a greater draught is needed without a greater volume of steam passing through the cylinders. An example of such situation is when the regulator is closed suddenly, or the train passes through a tunnel. If a single line tunnel is poorly ventilated, a locomotive entering at high speed can cause a rapid compression of the air within
217-418: Is a world record. In 1936, Chapelon began the rebuild of a PO 6000 class 2-10-0 as a 2-12-0 , with two high-pressure cylinders between the 2nd and 3rd coupled axles mounted behind four low-pressure cylinders. That unusual cylinder arrangement was required due to the loading gauge being too narrow to accommodate two low-pressure cylinders with the required volume to fully expand the low-pressure steam. There
248-456: The Chemin de Fer de Paris à Orléans (PO) and, along with Finnish Engineer Kyösti Kylälä , jointly designed the Kylchap exhaust system. While his principles met with scepticism, No. 3566, the first locomotive rebuilt to Chapelon's design, was an outstanding success, and from 1929 to 1936 several other locomotives were rebuilt to Chapelon's designs. In 1934, Chapelon was appointed Chevalier of
279-613: The École centrale Paris in 1919, from which he graduated as Ingénieur des Arts et Manufactures in 1921. He joined the Chemins de fer de Paris à Lyon et à la Méditerranée (PLM) as a probationer in the Rolling Stock and Motive Power section at Lyon-Mouche depot. However, foreseeing poor prospects, he left in 1924 and joined the Société Industrielle des Telephones, soon becoming as assistant manager. In 1925, he joined
310-882: The Legion of Honour and awarded both the Plumey Prize of the Académie des Sciences and the Gold Medal of the Société d'Encouragement pour l'Industrie Nationale . From 1938 he published the book for which he is most noted La locomotive à vapeur . On 13 September 1971 Chapelon was made Vice-President of the Stephenson Locomotive Society in a ceremony in Paris . He tested his experimental designs thoroughly to understand how they actually behaved, using
341-529: The basic principles of smokebox design took place until 1908, when the first comprehensive examination of steam-raising performance was carried out by W.F.M. Goss of Purdue University . These principles were adopted on the Great Western Railway by Churchward , and later developed by Samuel Ell in the 1950s using the GWR (then nationalised under BR) stationary testing plant. Ell was able to double
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#1732787636533372-511: The demise of commercial steam operations on mainline railways worldwide, there has been little funding for further development of steam locomotive technology, despite advances in materials technology and computer modelling techniques which might have enabled further improvements to efficiency. Andre Chapelon André Chapelon (26 October 1892 – 22 July 1978) was a French mechanical engineer and designer of advanced steam locomotives . A graduate engineer of Ecole Centrale Paris , he
403-404: The fire tubes by the draught. The blastpipe, from which steam is emitted, was mounted directly beneath the chimney at the bottom of the smokebox. The steam blast is largely self-regulating: an increase in the rate of steam consumption by the cylinders increases the blast, which increases the draught and hence the temperature of the fire. Modern locomotives are also fitted with a blower , which
434-497: The last compound locomotive of Czech origin. They consulted Chapelon during construction, and he visited Czechoslovakia. Chapelon published numerous works on steam locomotive design, although only his most famous work ( La locomotive a vapeur , described above) has been translated into English. The first locomotive rebuilt to incorporate Chapelon's work was PO 4-6-2 3566, which was released from Tours works in November 1929. As
465-597: The locomotive was scrapped in 1960. The SNCF 240P class is considered by some to be among Chapelon's best designs, and was the most thermally-efficient locomotive in the world at its time. According to some, it was equal in efficiency to early diesel locomotives of its time. The only locomotives Chapelon designed for use outside France were some metre gauge 2-8-4 and 4-8-4 locomotives for GELSA (Groupement d'Exportation de Locomotives S.A.) for export to Brazil . They were highly advanced locomotives with many modern American appliances, as well as Chapelon's innovations. He
496-459: The maximum steaming rate of the GWR Manor class by apparently minor alterations to the front end design, and more than doubled the rate for an LNER V2. Andre Chapelon made a significant improvement with his Kylchap exhaust which incorporated a Kylälä spreader (second stage nozzle) and third stage cowl between the blastpipe (first stage nozzle) and chimney. This became popular at the end of
527-494: The most accurate and complete testing and sensing equipment available, such as high-speed stroboscopic photography to watch steam flow. Before Chapelon, few engineers and designers tried to understand why a certain design worked better than another—they merely worked by trial and error , trying to replicate the attributes of previous locomotives by rule of thumb, by guesswork, and from empirical theories and design rules that had rarely been given adequate testing. Efficiency
558-415: The poor performance of the officially-approved locomotives. Chapelon's work lived on in the work of his friend and protégé Livio Dante Porta of Argentina , and others, and he was accorded the rare honour for a foreign railwayman of having a British Rail Class 86 electric locomotive named for him. Although many of Chapelon's contemporaries did not adopt his methods, a few did. One notable such designer
589-467: The principal reasons for the high performance of Rocket of 1829 at the Rainhill Trials . Soon after the power of the steam blast was discovered it became apparent that a smokebox was needed beneath the chimney, to provide a space in which the exhaust gases emerging from the boiler tubes can mix with the steam. This had the added advantage of allowing access to collect the ash drawn through
620-410: The steam circuit, including improving the steam flow by widening steam passages and paths, improving the flow through valve gear, and improved exhaust systems such as his Kylchap exhaust. Chapelon realised that in order to produce an efficient, powerful locomotive, every aspect of it had to be improved and dealt with scientifically. He studied locomotive behaviour at speed and the riding properties of
651-631: The steam era (early-mid 20th century) and was used on Sir Nigel Gresley 's Mallard which holds the official world speed record for steam locomotives. Other contemporary designs include the Giesl and Lemaître exhausts which achieve the same aim by different means. Further development was carried on by Chapelon's friend Livio Dante Porta , who developed the Kylpor , Lempor and Lemprex exhausts systems. He also developed sophisticated mathematical models to optimise their use for specific locomotives. With
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#1732787636533682-514: The steel wheel on steel rail; his knowledge was put to use much later on the French TGV high speed trains. Despite his abilities and track record, he was never presented the opportunity to design a class of entirely-new locomotives that were produced in any numbers. He was continually stymied by railway management and politicians, and often his superbly performing locomotives were treated as embarrassments by his superiors, because they showed up
713-401: The tunnel. This compressed air may enter the chimney with substantial force. This can be extremely dangerous if the firebox door is open at the time. For this reason the blower is often turned on in these situations, to counteract the compression effect. The aim of exhaust system development is to obtain maximum smokebox vacuum with minimum back pressure on the pistons. Little development of
744-595: Was Nigel Gresley of the British London and North Eastern Railway , who experimentally used Chapelon's Kylchap exhaust system on a small number of LNER Class A4 locomotives, including the LNER Class A4 4468 Mallard , which set what most historians accept as the world record for speed for steam locomotives in 1938. Czech locomotive designers at the Škoda Works watched Chapelon's work, especially when construction commenced on ČSD class 476.0 locomotive,
775-602: Was a great admirer of American industrial capacities and the resulting high quality of its engineering, even though his work tended to be ignored in the USA. One standard Gauge 4-4-2 was owned by the Pennsylvania Railroad Numbered 2512 which gained a Nickname De Glehn. Chapelon had several designs of standardised locomotive on the drawing board, starting with his time at P.O.Midi . Entirely new designs were drawn following his exposure to American ideas, with
806-473: Was also an additional level of "superheat" between the high- and low-pressure cylinders, allowing the loco to achieve a tractive effort of 83,700 pounds-force (372 kN)83700 lb. The 242 A 1 was perhaps the pinnacle of Chapelon's development of the steam locomotive. The 4-8-4 was a rebuild of Etat 4-8-2 241.101, which retained the 3-cylinder layout, changed it into a 3-cylinder compound system, and introduced more of Chapelon's improvements, including
837-542: Was an independent discovery or a copy of a design from one of the other engineers. The locomotives at the time employed either a single flue boiler or a single return flue , with the fire grate at one end of the flue. For boilers of this design the blast of a contracted orifice blastpipe was too strong, and would lift the fire. It was not until the development of the multi-tube boiler that the centrally positioned, contracted orifice blastpipe became standard. The combination of multi-tube boiler and steam blast are often cited as
868-480: Was born in Saint-Paul-en-Cornillon , Loire , France on 26 October 1892. According to family relatives, his great-grandfather James Jackson immigrated to France from England in 1812, one of many who came to France in the 19th century to teach steel production methods. He achieved a distinction in mathematics and science, and served as an artillery officer during World War I before returning to
899-401: Was directed up the chimney, and he noted its effect on increasing the draft through the fire at the time. At Wylam, Timothy Hackworth also employed a blastpipe on his earliest locomotives, but it is not clear whether this was an independent discovery or a copy of Trevithick's design. Shortly after Hackworth, George Stephenson also employed the same method but again it is not clear whether it
930-526: Was one of Chapelon's primary concerns in design. Some of his locomotives exceeded 12% efficiency, which for a steam locomotive was exceptional. With greater efficiency, Chapelon could achieve greater power in a smaller locomotive that burned less coal, rather than simply enlarging a locomotive for more power. He was a major proponent of the compound locomotive , and from 1929 on he rebuilt many de Glehn compounds, designed by Alfred de Glehn , with his system of compounding. His other major work included optimising
961-427: Was one of very few locomotive designers who brought a rigorous scientific method to their design, and he sought to apply up-to-date theories and knowledge in subjects such as thermodynamics , and gas and fluid flow. Chapelon's work was an early example of what would later be called modern steam , and influenced the work of many later designers of those locomotives, such as Livio Dante Porta . André Xavier Chapelon