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25-462: The Kylchap exhaust consists of four stacked nozzles, the first exhaust nozzle (UK: blastpipe ) blowing exhaust steam only and known as the primary nozzle, this being a Chapelon design using four triangular jets. This exhausts into the second stage, the Kylälä spreader, which mixes the exhaust steam with some of the smokebox gases; this then exhausts into a third stage, designed by Chapelon, that mixes

50-463: A blastpipe could lift the fire, pulling soot and sparks up the chimney. It was not until the development of the multitubular boiler that a forced draft could be used safely and effectively. The combination of multi-tube boiler and steam blast are often cited as the principal reasons for the high performance of Rocket of 1829 at the Rainhill Trials . Soon after the power of the steam blast

75-484: A simple expansion Pacific of the 3591 class, producing significant improvements in steaming and in one case a 41% reduction in back-pressure. However, it first came into prominence in 1929 when applied to compound Pacific No 3566 which combined enlarged steam circuits, increased superheat, feedwater heater, thermic syphon, Lentz poppet valves with double Kylchap exhaust extractors and chimneys. On test in November 1929,

100-471: Is fired up the middle of the stack bell-mouth. It would also ensure a more even flow through all the firetubes , rather than concentrating the suction on one area. The efficiency of the Kylchap system relied on careful proportioning of its components, and perfect alignment and concentricity. Chapelon developed the Kylchap exhaust in 1926 when it was tested on compound Pacifics of the 4500 and 3500 classes and

125-520: The Kylchap exhaust was popular and used on the Nigel Gresley -designed Mallard . Other designs include Giesl , Lemaître and Lempor blastpipes. Cylinder (engine) In a reciprocating engine , the cylinder is the space in which a piston travels. The inner surface of the cylinder is formed from either a thin metallic liner (also called "sleeve") or a surface coating applied to

150-641: The Lemaître , had some success in France and England. The noted Argentinian engineer, Livio Dante Porta , designed several: the Kylpor , Lempor and Lemprex systems. Several U.S. railroads, including the Norfolk & Western , used a concentric nozzle known as the "waffle iron exhaust". Blastpipe The blastpipe is part of the exhaust system of a steam locomotive that discharges exhaust steam from

175-435: The cylinders into the smokebox beneath the chimney in order to increase the draught through the fire. 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 –

200-525: The Stainmore Railway company industrial 0-4-0st locomotive 'F C Tingey', found at Kirkby Stephen East station. These exhausts were also fitted to some British-built export locomotives, primarily Garratt locomotives for Africa. The only other nation to take them up in quantity was Czechoslovakia , where all late normal gauge steam locomotives used this exhaust design. The Kylchap was not the only advanced steam locomotive exhaust. Another design,

225-489: The blower is often turned on in these situations, to counteract the compression effect. Little development of 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 George Jackson Churchward . A later development

250-437: The cylinder liner is subject to wear from the rubbing action of the piston rings and piston skirt. This wear is minimized by the thin oil film which coats the cylinder walls and also by a layer of glaze which naturally forms as the engine is run-in. On some engines, the cylinder liner is replaceable, in case it becomes worn or damaged. On engines without replaceable sleeves, the cylinder can sometimes be repaired by boring out

275-418: The cylinder. Cylinders were cast in cast iron and later in steel. The cylinder casting can include other features such as valve ports and mounting feet. The cylinder is the space through which the piston travels, propelled by the energy generated from the combustion of the air/fuel mixture in the combustion chamber. In an air-cooled engine , the walls of the cylinders are exposed to the airflow, to provide

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300-420: 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 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

325-403: The engine block. A piston is seated inside each cylinder by several metal piston rings , which also provide seals for compression and the lubricating oil. The piston rings do not actually touch the cylinder walls, instead they ride on a thin layer of lubricating oil. The cylinder in a steam engine is made pressure-tight with end covers and a piston; a valve distributes the steam to the ends of

350-530: The existing liner to produce a new smooth and round surface (although the diameter of the cylinder is slightly increased). Another repair technique is 'sleeving' the cylinder— boring it and then installing a sleeve in the extra space created by the boring. Most engines use 'dry liners', where the liner is surrounded by the engine block and does not make contact with the coolant. However, cylinders with 'wet liners' are used in some water-cooled engines, especially French designs. The wet liners are formed separately from

375-448: The front side of each cylinder, and the exhaust ports are on the rear side of each cylinder. Cylinder liners (also known as sleeves) are thin metal cylinder-shaped parts which are inserted into the engine block to form the inner wall of the cylinder. Alternatively, an engine can be 'sleeveless', where the cylinder walls are formed by the engine block with a wear-resistant coating, such as Nikasil or plasma-sprayed bores. During use,

400-585: The locomotive's indicated power output was found to have increased by over 60%, from 1850 ihp to 3000 ihp while its fuel and water consumption had improved by 25% compared to unrebuilt engines of the same class. These results made Chapelon's name and 3566 became well known both within France and in most countries of the Western world. Sir Nigel Gresley of the LNER became a proponent when he incorporated double Kylchap exhausts into four of his A4 Pacifics, including

425-402: The primary method of cooling to the engine. Most air-cooled engines have cooling fins on the cylinders and each cylinder has a separate case in order to maximise the surface area available for cooling. In engines where the cylinders are removable from the engine block, a removable single cylinder is called a jug. For motorcycle engines, a "reverse cylinder engine" is where the intake ports are on

450-458: The pure manufacturing cost was relatively low. The last steam express passenger locomotive built in Britain, Duke of Gloucester , was not fitted with a Kylchap exhaust in service, despite plans to fit one, but one was fitted in preservation when it was realised that poor draughting had been one of the biggest reasons behind its poor performance in its service days. A Kylchap exhaust is fitted to

475-404: The resulting steam/smokebox gases mixture with yet more smokebox gases. The four nozzles of this then exhaust into the fourth stage, the classic chimney (U.S.: stack) bell-mouth. It was Chapelon's theory that such a multi-stage mixing and suction arrangement would be more efficient than the single stage arrangement hitherto popular in steam locomotive draughting, in which an exhaust nozzle simply

500-417: 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 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

525-429: The world speed record holder Mallard . Arthur Peppercorn 's post-war LNER Pacifics also incorporated them, including preserved A2 532 Blue Peter , and the recreated A1 Tornado . Originally Kylchap exhausts were expensive and rarely used because the design was patented and subject to a licence fee but, after the patent expired, many more locomotives were retrofitted, including all the remaining A3 and A4 class, as

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550-401: Was an independent discovery or a copy of one of the other engineers. Goldsworthy Gurney was another early exponent, whose claim to primacy was energetically advocated by his daughter Anna Jane. 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. Because a single flue had to be wide to let the exhaust through,

575-402: 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, and again it is not clear whether that

600-400: 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 the fire tubes by the draught. The blastpipe, from which steam is emitted, was mounted directly beneath the chimney at the bottom of

625-402: Was the so-called jumper-top blastpipe which controlled the area of the blastpipe at different steaming rates to maximise efficiency. The aim of blastpipe modification is to obtain maximum smokebox vacuum with minimum back pressure on the pistons. The simplest modification is a double chimney with twin blastpipes, but many other arrangements have been tried. Towards the end of the steam era

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