There have been a vast number of designs of steam boiler, particularly towards the end of the 19th century when the technology was evolving rapidly. A great many of these took the names of their originators or primary manufacturers, rather than a more descriptive name. Some large manufacturers also made boilers of several types. Accordingly, it is difficult to identify their technical aspects from merely their name. This list presents these known, notable names and a brief description of their main characteristics.
See also Glossary of boiler terminology
A Definitions Points of Interest Admiralty three-drum boiler: the Royal Navy's standardised pattern of three-drum boiler. annular fire-tube boiler: a vertical fire-tube boiler with the tubes arranged radially, such as the Robertson. annular water-tube boiler: a vertical water-tube boiler with the tubes arranged radially, such as the Straker with horizontal tubes, or near-vertically and conically as used by Thornycroft for steam wagons. : An auxiliary boiler, on a steam ship, supplies steam that is not used for main propulsion, but is necessary for some part of the essential machinery.See also donkey boiler.A small boiler may be used as an auxiliary boiler when at sea, or a donkey boiler in port. A composite auxiliary boiler does this, using waste heat from the main engines when at sea, or is separately fired when acting as a donkey boiler. Auxiliary boilers were also present in some locomotives, in particular those used in passenger rail service, where steam was used as heating for the cars being pulled. With the advent of head end power, these steam boilers were phased out, often being replaced with concrete weights.
B Definitions Points of Interest Babcock-Johnson boiler: early production Johnson boilers operating at high pressures () and with water-wall ends to their furnace. Babcock & Wilcox boiler Babcock & Wilcox marine boiler Bagnall boiler: a development of the launch boiler, with an enlarged furnace. Also known in agricultural use as the 'colonial' or 'Britannia'. Belleville boiler: an early marine water-tube boiler developed in France by Julien Belleville.
Benson boiler: a monotube "once-through" steam generator. Blake boiler Blechynden boiler: An early naval water-tube boiler. Bolsover Express boiler box boiler: An early marine boiler with flat sides. Owing to the flat sides, even with extensive rod stays, the boilers were only suitable for low pressures. These boilers were physically large and contained a few large flues, each heated by its own furnace. The flues were round, rectangular or arched and usually long and labyrinthine. Brotan boiler: a rarely used boiler for steam locomotives that combined a conventional fire-tube boiler barrel with a water-tube firebox. There is a prominent steam drum above the boiler barrel, making it resemble a Flaman boiler. Brotan-Deffner boiler: a variant of the Brotan boiler. The steam drum was shortened and placed behind the boiler barrel, giving a much more conventional silhouette. Around a thousand of these were used in Hungary. Brotan-Fialovits boiler: a further variant of the Brotan-Deffner boiler. bundled-tube water-tube boiler; early large-tube water-tube boilers where the tubes were grouped into bundles (of 19, for geometrical reasons) that shared a common header, so as to improve shared access for tube cleaning. Butterley boiler: a form of Cornish boiler where the furnace was opened up into a "whistle mouth", enlarging the grate area.
C Definitions Points of Interest Clarke Chapman "Tyne" boiler: a form of vertical water-tube boiler, a development of the cross-tube boiler intended to encourage better water circulation. Clarke Chapman "Victoria" boiler: a form of vertical cross-fire-tube boiler. Clarkson thimble tube boiler: the original thimble-tube boiler, using a great many short closed-ended watertubes. Often used for heat-recovery from the exhaust of large Diesel engines. Climax boiler: A vertical water-tube boiler with many long spiral coils around a central steam-and-water drum. Cochran boiler: a vertical boiler with horizontal fire-tubes. composite boiler: a boiler used for either direct-firing, or as a heat-recovery boiler. Corner tube boiler: a natural circulation water tube boiler in which the pre-separation of steam takes place from the water-steam mixture outside the drum and the preheated downcomers. Cornish boiler: a large horizontal stationary boiler with a single flue. cross-tube boiler: usually a vertical flued boiler with a small number of large water-carrying cross-tubes within the firebox. The term is also applied to vertical boilers with other arrangements of tubes, such as those with horizontal fire-tubes. Crosti boiler:
D Definitions Points of Interest De Poray boiler: patented French designs with a secondary combustion chamber to improve combustion efficiency. A vertical form of this uses field-tubes. Doble steam-car boiler: : A donkey boiler is used to supply non-essential steam to a ship for 'hotel' services such as heating or lighting when the main boilers are not in steam, for example, when in port. Donkey boilers were also used by the last sailing ships for working winches and anchor capstans.See also auxiliary boiler. du Temple boiler: An early naval water-tube boiler, patented in 1876. Dublin "economic" boiler: a vertical multitubular return fire-tube design, for model engineering-scale uses. Dürr boiler An early naval water-tube boiler, developed and mostly used in Germany, but also trialled in the British
E Definitions Points of Interest egg-ended boiler: an early form of tubular wagon boiler, with hemispherical ends to support higher pressures. Elephant boiler: an early multi-cylindered wagon boiler, popular in France. express boiler: another term for small-tube water-tube boilers, on account of their high ratio between heating surface area and water volume, and thus their rapid steam-raising.
F Definitions Points of Interest Fairbairn's five-tube boiler Fairbairn-Beeley boiler, a fire-tube boiler with multiple joined shells of small diameter Fairfield-Johnson boiler: a later form of Johnson boiler operating at lower pressure ( rather than ), but still a high superheat temperature . Fairlie boiler: A double-ended locomotive boiler with a central firebox, used in Fairlie's patent for double-ended articulated steam locomotives. field-tube boiler: fire-tube boiler: A boiler with many narrow fire-tubes inside a water drum. A development of the flued boiler, where the many smaller tubes give a much larger heating surface area for the overall boiler volume. Flaman boiler: an attempt to squeeze the largest possible locomotive boiler into the loading gauge by splitting the boiler into two drums: a fire-tube boiler beneath and a steam drum above. flued boiler: A boiler with only one or two large diameter fire-tubes inside a water drum. These later developed into the fire-tube boiler. forced-circulation boiler: boilers where circulation is forced by a pump, rather than relying on thermosyphon effect. These may use either forced-water-circulation (e.g. La Mont) or forced-steam-circulation (e.g. Löffler). Foster-Wheeler boiler D type controlled-superheat type ESD type (External Superheat, D type) Franco-Crosti boiler:
G Definitions Points of Interest Galloway boiler: a Lancashire boiler fitted with Galloway tubes. Originally these fused the Lancashire boiler's original two flues into a single kidney-shaped flue, with the tubes mounted in the joined section. Later boilers kept the cylindrical flues separate and placed the tubes within them. gothic boiler: an early locomotive boiler, where the outer firebox was particularly large and served as the steam dome, often highly decorated with polished brass. These were popular for early railway locomotives, from 1830 to 1850. This is another form of boiler frequently described as a "haystack". gunboat boiler: similar to the commonly known locomotive boiler, from steam locomotives.A horizontal boiler drum contains multiple fire-tubes and a separate furnace. However, the furnace in a gunboat boiler has no opening at the bottom of the furnace to allow dumping of ash; the furnace is completely water-cooled, similar to a Scotch boiler furnace. These boilers were used in early torpedo boats and gunboats, having low height for protection from enemy gunfire.
H Definitions Points of Interest Harris "Economic" boiler haystack boiler: Early balloon- or haystack-shaped, circular in plan with a domed top and often a flat base. See also Napier and gothic, quite different designs also described as "haystack" boilers. heat-recovery boiler: a boiler without its own furnace, used to recover heat from some earlier process, such as a large marine Diesel engine or an industrial furnace. Hornsby boiler: a form of bundled-tube water-tube boiler. Huber boiler: a return-tube boiler used in the Huber company's traction engines.
I Definitions Points of Interest Illingworth boiler: a water-tube boiler. Inglis: a modified form of the Scotch boiler, with an additional combustion chamber.
J Definitions Points of Interest Johnson boiler: one of the first "modern" classes of high-pressure marine oil-fired water-tube boilers. They have a single steam drum above a single water drum. Their small-diameter water-tubes curve outwards on each side to form a cylindrical furnace. As there is no grate or ashpan beneath, firing must be by oil. Return circulation is by external downcomers. Early versions also used water-walls at each end of the furnace, later ones had plain firebrick walls.
K Definitions Points of Interest Kier: (sometimes Keeve or Kieve) an un-fired boiler, a pressure vessel heated by an external steam supply, used for bleaching in dyeworks and processing paper pulp. In use they were continuously rotated by an engine, steam being supplied through a rotating joint in the axle. They were usually spherical, sometimes cylindrical, and some were recycled from old boiler shells.
Kingdom boiler: an uncommon pattern of water-tube boiler. Kewanee Boiler Corporation: Maker of fire tube boilers
L Definitions Points of Interest La Mont boiler: a forced-water-circulation boiler. They are often used as marine heat-recovery boilers. It was also used, unsuccessfully, for an experimental steam locomotive in East Germany in the 1950s. Lancashire boiler: a development of the Cornish boiler, with two flues. large-tube water-tube boiler: early water-tube boilers with large diameter water-tubes, of 3 inches and above, rather than the later small-tube designs. Larsen & Toubro MHI Boilers: Super Critical Boilers. launch-type boiler: a small fire-tube boiler used in launches and smaller steam yachts. A horizontal cylinder in form, with a cylindrical furnace and multiple fire-tubes. They have some resemblance to a small Scotch boiler or Huber boiler, but with the fire-tubes extending beyond the furnace end, rather than folded back as a return-tube boiler. Sometimes small return-tube boilers of just this form are also described as "launch-type". Lentz boiler A large launch-type boiler with a corrugated furnace, used rarely for some steam locomotives. Of German design. A similar boiler, the Vanderbilt, was used in the USA. Locomobile steam-car boiler locomotive boiler: the commonly known form familiar from steam locomotives.A horizontal boiler drum contains multiple fire-tubes and a separate firebox. Löffler boiler: a forced-steam-circulation boiler. It was used unsuccessfully on a German steam locomotive of the 1930s. Lune Valley boiler
M Definitions Points of Interest Monotube steam generator: A single tube, usually in a multi-layer spiral, that forms a once-through steam generator. The first of these was the Herreshoff steam generator of 1873.