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Mastodon was the unofficial name of the Central Pacific Railroad's number 229, the world's first successful 4-8-0 steam locomotive.
The engine was designed and built by the road's master mechanic, Andrew Jackson "A.J" Stevens at Sacramento Locomotive Works in 1882. The locomotive had two highly unusual features: the firebox shape and the steam distribution.
The rear end of the firebox was depressed so that the outer shell was below the water level, leaving no clear steam space. The roof was sloped down towards the back so that steam bubbles would flow forward till they reached the upper vertical part of the backplate which was in two pieces. The fire-hole door was in the lower backplate. The firebox was very long, 13 ft 4+3⁄4 in (4.08 m) to the tubeplate, the grate being 9 ft (2.74 m) long. It is not clear what object Stevens had in mind when having this abnormal construction, which must have been costly to build and maintain: it did give more room in the cab. The special valve gear operated four slide valves for each cylinder, two of which were worked by Stephenson valve gear, but used for reversing only, and two more, on top of the first two, for controlling the cutoff, these being operated by a third eccentric through a rocking lever with a sliding block on one arm. The use of a double valve gear is reminiscent of Centipede, but separate valves for each end of the cylinder were novel on a locomotive. This valve gear gave very good steam distribution even at short cut-offs; short as understood for a saturated-steam engine with a boiler pressure low by modern standards. At long cut-off and a speed of 8 miles per hour (13 km/h) the indicated mean effective pressure was 124 lb/sq in (8.5 bar), which is over 91 per cent of the boiler pressure of 135 lb/sq in (9.3 bar), that is to say more than the 85 per cent normally used to calculate the tractive effort at starting. [1]
The only other locomotives to use such a valve gear were the 20 copies of Mastodon (see below) and CPR #237 El Gobernador. All other steam locomotives with slide valves had just a single valve in the center.
After being readied for its initial shakedown run, the engine met with a minor mishap in which its large "balloon" stack was knocked away from the boiler. During all the careful preparations, apparently nobody noticed that the stack was nearly one foot (30 cm) taller than the doors to the roundhouse. The problem was fixed and an impressive series of trials on the steep grades of the Sierra Nevada soon followed, in which it easily outperformed the smaller 4-4-0 and 4-6-0 engines used by the railroad in those days. Later, Mastodon was sent east to the Cooke Locomotive and Machine Works, along with blueprints and men who had built the engine, where more than 20 copies were produced; these were identical except for having their cylinder bore increased to 20 inches (508 mm) (from Mastodon's 19 inches or 483 millimeters). The success of this engine inspired railroad president Leland Stanford to instruct Stevens to build an even larger locomotive, which would be the largest the world had ever seen up until that time. This engine, a 4-10-0 named El Gobernador (CPRR #237), looked virtually identical to Mastodon, with the exception of being longer and having an additional pair of driving wheels. Unfortunately, this engine, unlike its predecessor, was doomed to failure and was scrapped in 1894.
Sometime in the early 20th century, No. 229 (now renumbered as Southern Pacific 2925) was converted from wood to oil-firing and was later assigned to the Oregon lines. Despite its historical significance, the engine was broken up for scrap at the Brooklyn Shops in Portland, Oregon, in June 1935 after a working life of 53 years.
A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material to heat water in the locomotive's boiler to the point when it becomes gaseous and its volume increases 1,700 times. Functionally, it is a steam engine on wheels.
Under the Whyte notation for the classification of steam locomotives, 4-6-2 represents the wheel arrangement of four leading wheels on two axles, six powered and coupled driving wheels on three axles and two trailing wheels on one axle. The 4-6-2 locomotive became almost globally known as a Pacific type.
Rail terminology is a form of technical terminology. The difference between the American term railroad and the international term railway is the most significant difference in rail terminology. There are also others, due to the parallel development of rail transport systems in different parts of the world.
The M1 was a class of steam locomotive of the Pennsylvania Railroad (PRR). It was a class of heavy mixed-traffic locomotives of the 4-8-2 "Mountain" arrangement, which uses four pairs of driving wheels with a four-wheel guiding truck in front for stability at speed and a two-wheel trailing truck to support the large firebox needed for sustained power. Although built for both passenger and freight work, they spent most of their service lives hauling heavy high-speed freight trains. Many PRR men counted the M1 class locomotives as the best steam locomotives the railroad ever owned.
Under the Whyte notation for the classification of steam locomotives, 4-8-0 represents the wheel arrangement of four leading wheels on two axles, usually in a leading truck or bogie, eight powered and coupled driving wheels on four axles and no trailing wheels. In North America and in some other countries the type was usually known as the Twelve-wheeler.
The GWR 4100 Class was a class of steam locomotives in the Great Western Railway (GWR) of the United Kingdom.
The Great Western Railway 3252 or Duke Class were 4-4-0 steam locomotives with outside frames and parallel domed boilers. They were built in five batches between 1895 and 1899 for express passenger train work in Devon and Cornwall. William Dean was their designer, possibly with the collaboration of his assistant, George Jackson Churchward. Four prototype 4-4-0s, of the Armstrong Class, had already been built in 1894.
Under the Whyte notation for the classification of steam locomotives by wheel arrangement, 2-6-6-0 is a locomotive with one pair of unpowered leading wheels, followed by two sets of three pairs of powered driving wheels and no trailing wheels. The wheel arrangement was principally used on Mallet-type articulated locomotives. Some tank locomotive examples were also built, for which various suffixes to indicate the type of tank would be added to the wheel arrangement, for example 2-6-6-0T for an engine with side-tanks.
The Belpaire firebox is a type of firebox used on steam locomotives. It was invented by Alfred Belpaire of Belgium in 1864. Today it generally refers to the shape of the outer shell of the firebox which is approximately flat at the top and square in cross-section, indicated by the longitudinal ridges on the top sides. However, it is the similar square cross-section inner firebox which provides the main advantages of this design i.e. it has a greater surface area at the top of the firebox where the heat is greatest, improving heat transfer and steam production, compared with a round-top shape.
The London and North Eastern Railway LNER Gresley Classes A1 and A3 locomotives represented two distinct stages in the history of the British 4-6-2 "Pacific" steam locomotives designed by Nigel Gresley. They were designed for main line passenger services and later express passenger services, initially on the Great Northern Railway (GNR), a constituent company of the London and North Eastern Railway after the amalgamation of 1923, for which they became a standard design. The change in class designation to A3 reflected the fitting to the same chassis of a higher pressure boiler with a greater superheating surface and a small reduction in cylinder diameter, leading to an increase in locomotive weight. Eventually all of the A1 locomotives were rebuilt, most to A3 specifications, but no. 4470 was completely rebuilt as Class A1/1.
The New York Central Railroad's Niagara was a 4-8-4 "Northern" type steam locomotive named after the Niagara River and Falls. It had a 4-8-4 wheel arrangement and is considered as one of the most efficient 4-8-4 locomotives ever built.
El Gobernador was a 4-10-0 steam locomotive built by Central Pacific Railroad at the railroad's Sacramento, California shops. It was the last of Central Pacific's locomotives to receive an official name and was also the only locomotive of this wheel arrangement to operate on United States rails. At the time it was built, El Gobernador was the largest railroad locomotive ever built. Its name is reminiscent of the railroad's first locomotive, Gov. Stanford, as El Gobernador is Spanish for The Governor. This locomotive is a Mastodon type. Confusingly, this was the unofficial name for an earlier engine, "Mastodon" No. 229, the first successful 4-8-0 ever built. Both engines looked nearly identical, except that El Gobernador was longer and had an additional pair of drivers.
The Norfolk and Western Railway's M, M1 and M2 classes were a series of 4-8-0 steam locomotives owned and operated by the Norfolk and Western Railway.
The South African Railways Class 16E 4-6-2 of 1935 was a steam locomotive.
The South African Railways Class 16 4-6-2 of 1914 was a steam locomotive.
The South African Railways Class 8X 2-8-0 of 1901 was a steam locomotive from the pre-Union era in the Cape of Good Hope.
The South African Railways Class 1A 4-8-0 of 1910 was a steam locomotive from the pre-Union era in the Colony of Natal.
The South African Railways Class 3 4-8-2 of 1909 was a steam locomotive from the pre-Union era in the Colony of Natal.
The South African Railways Class MD 2-6-6-2 of 1910 was a steam locomotive from the pre-Union era in Transvaal.
The L&YR 2-10-0 was a prospective design for a class of 2-10-0 steam locomotives on the Lancashire and Yorkshire Railway. Initial designs were made by George Hughes between 1913–1914, but none of the class were built. If they had been, these would have been the UK's first 10-coupled locomotives in regular service.