Crewe Works is a British railway engineering facility built in 1840 by the Grand Junction Railway. It is located in Cheshire, it is owned by Bombardier Transportation. The railway built 200 cottages establishing a new community in what had been the rural township of Monks Coppenhall. Among the first workers to arrive were those from the old works at Edge Hill producing an increase in the town's population by some 800 men and children; the first locomotive built at Crewe went into service in 1843. By 1846 the demand for space was such that wagon building was moved, first to Edge Hill and Manchester to a new works at Earlestown. By 1848 the works employed over 1,000 producing one locomotive a week. In 1845 the Liverpool and Manchester Railway was merged with the Grand Junction. These, in turn, merged in 1846, with the London and Birmingham Railway and the Manchester and Birmingham Railway to form the London and North Western Railway. All four had their own workshops but, in time, locomotive building was concentrated at Crewe.
In 1857 John Ramsbottom became Locomotive Superintendent. He had invented the first reliable safety valve and the scoop for picking up water from troughs between the tracks, he went on to improve the interchangeability of tools and components. In 1862 locomotive work was transferred from Wolverton. Wolverton became. In 1853 Crewe had begun to make its own wrought iron and roll its own rails, in 1864 installed a Bessemer converter for manufacturing steel. In 1868 it became the first place to use open-hearth furnaces on an industrial scale, it built its own brickworks. The works was fitted with two electric arc furnaces. Production increased and, with the sale to the Lancashire and Yorkshire Railway of ten 2-4-0 and eighty six 0-6-0 locomotives owned manufacturers took out an injunction in 1876 to restrain the railway from producing anything but its own needs; this remained in force until British Rail Engineering Limited was established in 1969. When the LNWR became part of the London and Scottish Railway in 1923 its passenger locomotives were eclipsed by those of the former Midland Railway, which offered light and frequent services.
As traffic density increased there was a need for longer trains and more powerful locomotives to haul them. In 1932, William Stanier set out to rationalise production. Since Crewe had experience with heavier locomotives and had its own steel making facilities, he chose it as his main production location. There followed the Princesses and Duchesses, along with the Jubilees and the "Black Fives". Crewe produced all the new boilers for the LMS, all heavy drop stampings and forgings, it produced most of the heavy steel components for the track and other structures. During World War II, Crewe produced over 150 Covenanter tanks for the army. After British Railways was formed in 1948, Robert Riddles introduced the BR standard classes, Crewe built Britannia and Clan mixed traffic engines and some of the Class 9 freight locomotives; the last steam locomotive, Class 9 number 92250, was completed in December 1958. Crewe Works built 7.331 steam locomotives. Diesel production commenced with D5030 the first main line example completed in 1959.
The final diesel locomotives built at Crewe Works were the Class 56 with the last completed in 1984, while the final class of electric locomotives were the Class 91 with the last completed in 1991. Much of the site at Crewe was cleared in a major redevelopment in the mid 1980s. Crewe works became a part of British Rail Engineering Limited when the former BR Workshops were set up as a separate business in 1969 and was privatised in 1989; this company was soon sold to ASEA Brown-Boveri, which merged with Daimler Benz in 1996 to form Adtranz. Adtranz was itself taken over by Bombardier in 2001. At its height, Crewe Works employed over 20,000 people. Current work is focused on general maintenance, the inspection of damaged stock. Much of the site once occupied by the works has been sold off and is now occupied by a supermarket, leisure park, a large new health centre. From 1862 until 1932, the works was served by an internal narrow gauge tramway, the Crewe Works Railway. Under the London and North Western Railway, Crewe Works produced many famous locomotives: the Webb 2-4-0 Jumbo class and the compounds, the Whale Experiment and Precursor classes, the Bowen-Cooke Claughtons.
In particular, Whale's 1912 superheated G1 Class 0-8-0 developed from a locomotive introduced by Webb in 1892, lasted, in many cases until 1964, near the end of steam in 1968. Under the London and Scottish Railway, the works was noted for Sir William Stanier's locomotives and in particular the'Jubilee' 4-6-0s, the Class 5 mixed traffic 4-6-0s and the'Princess Royal' and'Princess Coronation' 4-6-2s. Under British Railways, the works built many notable steam designs including the Britannia 4-6-2s and the Franco-Crosti boilered Class 9 freight locomotives. Mitchell, Vic. Stafford to Chester. West Sussex: Middleton Press. Figs. 76-80. ISBN 9781908174345. OCLC 830024480. Kelly, Peter. "This is Crewe". Rail Enthusiast. EMAP National Publications. Pp. 16–19. ISSN 0262-561X. OCLC 49957965. Official website
Severn Valley Railway
The Severn Valley Railway is a heritage railway in Shropshire and Worcestershire, England. The 16-mile heritage line runs along the Severn Valley from Bridgnorth to Kidderminster, crossing the Shropshire/Worcestershire border, following the course of the River Severn for much of its route. Train services are hauled predominantly by steam locomotives, plus one diesel hauled train, making two round trips a day, on most days. Diesel locomotives are used for engineering trains, to replace failed steam locomotives at short notice, during periods of high fire risk; the railway is one of the most popular heritage railways in the country as well as being the sixth-longest standard gauge heritage line in the United Kingdom. It hosts numerous special events throughout the year, including diesel galas; the Severn Valley Railway was built between 1858 and 1862, linked Hartlebury, near Droitwich Spa, with Shrewsbury, a distance of 40 miles. Important stations on the line were Stourport-on-Severn and Arley within Worcestershire, Highley, Hampton Loade, Coalport and Broseley, Buildwas and Berrington in Shropshire.
Although the railway was built by the original Severn Valley Railway Company, it was operated from opening on 1 February 1862 by the West Midland Railway, absorbed into the Great Western Railway on 1 August 1863. As one of the many branch lines on the GWR’s extensive network, it was subsequently referred to in GWR timetables as the Severn Valley Branch. In 1878 the GWR opened a link line between Kidderminster; this meant. Most Kidderminster to Bewdley trains continued through the Wyre Forest line to Tenbury Wells or Woofferton. At Buildwas Junction Severn Valley trains connected with services from Wellington to Much Wenlock and Craven Arms; the line was planned as double-track but was built and operated as a single-track railway. Prior to preservation, the Severn Valley line was never financially successful. Freight traffic agricultural, coal traffic from the collieries of Alveley and Highley were the principal sources of revenue; the line was strategically useful in the Second World War as an alternative diversionary route around the West Midlands.
After nationalisation in 1948, passenger traffic started to dwindle. Although the Severn Valley Branch was closed during the Beeching cuts of the 1960s, it was scheduled for closure prior to the publication of Beeching's report'The Reshaping of British Railways' on 27 March 1963. British Railways had announced in January 1962 that the Severn Valley Branch was under review, the B. T. C. Published closure proposal notices on 1 October 1962 in advance of a meeting of the West Midlands Transport Users Consultative Committee which took place at Bridgnorth Town Hall on 8 November 1962. Objections to the proposed closure were unsuccessful and the line was closed to through passenger services on 9 September 1963 and to through freight services on 30 November 1963. Following closure, the track north of Bridgnorth was dismantled. After 1963, coal traffic survived south of Alveley until 1969, while a sparse passenger service continued to link Bewdley with Kidderminster and Hartlebury, until this too ceased in January 1970.
Freight traffic between the British Sugar Corporation’s Foley Park factory and Kidderminster continued until 1982. For much of its working life the Severn Valley line was operated by the Great Western Railway and subsequently the Western Region of British Railways. Today the Severn Valley Railway operates as a heritage railway; the Severn Valley Railway Society was formed in July 1965 by a group of members who wished to preserve a section of the line which had closed in 1963. To achieve this, a new Severn Valley Railway Company was incorporated in May 1967. At that early date, the objective of the company was to ‘preserve and restore the standard-gauge railway extending from Bridgnorth to Kidderminster via Bewdley’; the SVR acquired 5½ miles of the line between Bridgnorth and Alveley Colliery from BR at a cost of £25,000. In May 1970 a Light Railway Order was granted allowing services to begin between Bridgnorth and Hampton Loade; the end of coal trains from the colliery in 1969 allowed SVR to acquire a further 8½ miles of the line as far as Foley Park in 1972, the purchase price of £74,000 being raised by the flotation of a public company under the chairmanship of Sir Gerald Nabarro.
In 1973 a dispute between Nabarro and the volunteer workforce led to the threat of a strike, resolved when he was succeeded as Chairman by Viscount Garnock in March and resigned from the Board two months later. Services were extended to Bewdley in May 1974. Following the end of freight traffic from BSC at Foley Park in 1982, the SVR purchased the final section of the line to Kidderminster at a cost of £75,000; the SVR rented the former Comberton Hill goods yard at Kidderminster from BR, on which a new station would be built. This was achieved in time for services to Kidderminster to begin on 30 July 1984. Major developments on the SVR since 1984 have included the commissioning of a newly constructed signal box at Kidderminster in 1987, the opening of a new boiler shop at Bridgnorth in 1990, the purchase of the freehold of Kidderminster Town station in 1994, the opening of a new carriage shed at Kidderminster in 2003, the completion of the east wing and canopy of Kidderminster Station in 2006, the opening of the Engine House Museum at Highley in 2008.
2010 marked the Severn Valley railway's 40th anniversary since opening in 1970 and the 175th anniversary of
A safety valve is a valve that acts as a fail-safe. An example of safety valve is a pressure relief valve, which automatically releases a substance from a boiler, pressure vessel, or other system, when the pressure or temperature exceeds preset limits. Pilot-operated relief valves are a specialized type of pressure safety valve. A leak tight, lower cost, single emergency use option would be a rupture disk. Safety valves were first developed for use on steam boilers during the Industrial Revolution. Early boilers operating without them were prone to explosion unless operated. Vacuum safety valves are used to prevent a tank from collapsing while it is being emptied, or when cold rinse water is used after hot CIP or SIP procedures; when sizing a vacuum safety valve, the calculation method is not defined in any norm in the hot CIP / cold water scenario, but some manufacturers have developed sizing simulations. The earliest and simplest safety valve was used on a 1679 steam digester and utilized a weight to retain the steam pressure.
On the Stockton and Darlington Railway, the safety valve tended to go off when the engine hit a bump in the track. A valve less sensitive to sudden accelerations used a spring to contain the steam pressure, but these could still be screwed down to increase the pressure beyond design limits; this dangerous practice was sometimes used to marginally increase the performance of a steam engine. In 1856, John Ramsbottom invented a tamper-proof spring safety valve that became universal on railways; the Ramsbottom valve consisted of two plug-type valves connected to each other by a spring-laden pivoting arm, with one valve element on either side of the pivot. Any adjustment made to one of valves in an attempt to increase its operating pressure would cause the other valve to be lifted off its seat, regardless of how the adjustment was attempted; the pivot point on the arm was not symmetrically between the valves, so any tightening of the spring would cause one of the valves to lift. Only by removing and diassembling the entire valve assembly could its operating pressure be adjusted, making impromptu'tying down' of the valve by locomotive crews in search of more power impossible.
The pivoting arm was extended into a handle shape and fed back into the locomotive cab, allowing crews to'rock' both valves off their seats to confirm they were set and operating correctly. Safety valves evolved to protect equipment such as pressure vessels and heat exchangers; the term safety valve should be limited to compressible fluid applications. The two general types of protection encountered in industry are thermal protection and flow protection. For liquid-packed vessels, thermal relief valves are characterized by the small size of the valve necessary to provide protection from excess pressure caused by thermal expansion. In this case a small valve is adequate because most liquids are nearly incompressible, so a small amount of fluid discharged through the relief valve will produce a substantial reduction in pressure. Flow protection is characterized by safety valves that are larger than those mounted for thermal protection, they are sized for use in situations where significant quantities of gas or high volumes of liquid must be discharged in order to protect the integrity of the vessel or pipeline.
This protection can alternatively be achieved by installing a high integrity pressure protection system. In the petroleum refining, chemical manufacturing, natural gas processing, power generation, drinks and pharmaceuticals industries, the term safety valve is associated with the terms pressure relief valve, pressure safety valve and relief valve; the generic term is pressure safety valve. PRVs and PSVs are not the same thing, despite. Relief valve: an automatic system, actuated by the static pressure in a liquid-filled vessel, it opens proportionally with increasing pressure. Safety valve: an automatic system that relieves the static pressure on a gas, it opens accompanied by a popping sound. Safety relief valve: an automatic system that relieves by static pressure on both gas and liquid. Pilot-operated safety relief valve: an automatic system that relieves on remote command from a pilot, to which the static pressure is connected. Low pressure safety valve: an automatic system that relieves static pressure on a gas.
Used when the difference between the vessel pressure and the ambient atmospheric pressure is small. Vacuum pressure safety valve: an automatic system that relieves static pressure on a gas. Used when the pressure difference between the vessel pressure and the ambient pressure is small and near to atmospheric pressure. Low and vacuum pressure safety valve: an automatic system that relieves static pressure on a gas. Used when the pressure difference is small, negative or positive and near to atmospheric pressure. RV, SV and SRV are spring-operated. LPSV and VPSV are weight-loaded. In most countries, industries are required to protect pressure vessels and other equipment by using relief valves. In most countries, equipment design codes such as those provided by the ASME, API and other organizations like ISO mus
The Whyte notation for classifying steam locomotives by wheel arrangement was devised by Frederick Methvan Whyte, came into use in the early twentieth century following a December 1900 editorial in American Engineer and Railroad Journal. The notation counts the number of leading wheels the number of driving wheels, the number of trailing wheels, numbers being separated by dashes. Other classification schemes, like UIC classification and the French and Swiss systems for steam locomotives, count axles rather than wheels. In the notation a locomotive with two leading axles in front three driving axles and one trailing axle is classified as 4-6-2, is known as a Pacific. Articulated locomotives such as Garratts, which are two locomotives joined by a common boiler, have a + between the arrangements of each engine, thus a "double Pacific" type Garratt is a 4-6-2+2-6-4. For Garratt locomotives the + sign is used when there are no intermediate unpowered wheels, e.g. the LMS Garratt 2-6-0+0-6-2. This is because the two engine units are more than just power bogies.
They are complete engines, carrying fuel and water tanks. The + sign represents the bridge that links the two engines. Simpler articulated types such as Mallets have a jointed frame under a common boiler where there are no unpowered wheels between the sets of powered wheels; the forward frame is free to swing, whereas the rear frame is rigid with the boiler. Thus a Union Pacific Big Boy is a 4-8-8-4; this numbering system is shared by duplex locomotives, which have powered wheel sets sharing a rigid frame. No suffix means a tender locomotive. T indicates a tank locomotive: in European practice, this is sometimes extended to indicate the type of tank locomotive: T means side tank, PT pannier tank, ST saddle tank, WT well tank. T+T means a tank locomotive that has a tender. In Europe, the suffix R can signify rack or reversible, the latter being Bi-cabine locomotives used in France; the suffix F indicates a fireless locomotive. This locomotive has no tender. Other suffixes have been used, including ng for narrow-gauge and CA or ca for compressed air.
In Britain, small diesel and petrol locomotives are classified in the same way as steam locomotives, e.g. 0-4-0, 0-6-0, 0-8-0. This may be followed by D for diesel or P for petrol, another letter describing the transmission: E for electric, H hydraulic, M mechanical. Thus, 0-6-0DE denotes a six-wheel diesel locomotive with electric transmission. Where the axles are coupled by chains or shafts or are individually driven, the terms 4w, 6w or 8w are used. Thus, 4wPE indicates a four-wheel petrol locomotive with electric transmission. For large diesel locomotives the UIC classification is used; the main limitation of Whyte Notation is that it does not cover non-standard types such as Shay locomotives, which use geared trucks rather than driving wheels. The most used system in Europe outside the United Kingdom is UIC classification, based on German practice, which can define the exact layout of a locomotive. In American practice, most wheel arrangements in common use were given names, sometimes from the name of the first such locomotive built.
For example, the 2-2-0 type arrangement is named Planet, after the 1830 locomotive on which it was first used. The most common wheel arrangements are listed below. In the diagrams, the front of the locomotive is to the left. AAR wheel arrangement Swiss locomotive and railcar classification UIC classification Wheel arrangement Boylan, Richard. "American Steam Locomotive Wheel Arrangements". SteamLocomotive.com. Retrieved 2008-02-08. Media related to Whyte notation at Wikimedia Commons
Novelty was an early steam locomotive built by John Ericsson and John Braithwaite to take part in the Rainhill Trials in 1829. It is now regarded as the first tank engine, it had a number of other novel design features. Several of the major components had significant design weaknesses which resulted in its failure at the Trials. During the late 1820s Ericsson and Braithwaite were working together building horse drawn fire engines with steam pumps; these were built in the London works of John Braithwaite. These fire engines were known for their ability to raise steam and looked similar to Novelty. Charles Vignoles has been associated with Novelty, but his practical involvement is not known, he may have aligned himself with the engine because of a continuing feud with George Stephenson. It is said that Ericsson and Braithwaite only found out about the Rainhill Trials seven weeks before the event was due to take place, when Ericsson received a letter from a friend referring to a "Steam Race"; this short space of time has led people to suggest that Novelty is in fact a converted fire engine.
It is more that it used many of the same parts as their fire engines and these parts may have been built for an existing order and diverted to Novelty. Novelty was constructed in the London Workshop belonging to Braithwaite and transported to Liverpool by boat. There was no time to test Novelty in London before transportation, following test runs at Rainhill before the trials, modifications were carried out with the help of Timothy Hackworth; the boiler used on Novelty was designed by John Ericsson. The design was scientific for the era but proved to be hard to build and maintain compared with the boiler design adopted for Rocket and most steam locomotives since; the most prominent feature for the boiler is the vertical copper firebox. Within the vertical vessel was the inner firebox and the space between the two was filled with water. Fuel was added from the top; this firebox construction was not dissimilar to some types of vertical boiler, but this was only part of Ericsson’s design. Like George Stephenson, Ericsson understood that a large area was needed to extract heat from the hot gases.
This he did in a long horizontal tube filled with water which ran under the full length of the engine. It can be seen in the illustration on top of this page, sticking out to the right, with the vertical chimney attached to it. Within the horizontal section was a tube carrying the hot gases, this formed an ‘S’ shape so the gases made three passes through the water; this ‘S’ shaped tube was tapered causing the gases to speed up as they cooled down. In practice this tube is impossible to clean; the resulting boiler was the shape of a hammer and was required to be fitted to the frame before the footplate, cylinders or blower could be added. The boiler used; this forced air into the sealed ashpan. Few steam locomotives have used a forced draught like this, the main reason is that in order to add fuel either the draft must be stopped or some form of airlock fitted. Novelty used an airlock to feed the fuel in, but there was still a chance of flame and hot gases being blown into the face of the fireman.
The blower was driven from the rods linking the cylinders to the wheels, thus the draught was proportional to the speed of the engine, not to how hard it is working as with a blastpipe. It is assumed that either the blower was worked by hand when the engine was standing or the drive wheels were lifted off the rails. Details of the blower design are not known for certain. Water was forced into the boiler using a pump driven off one of the cylinders. At this time, engineers were worried about uneven wear on pistons and cylinders when they were mounted horizontally, so most were mounted vertically, but vertical cylinders driving directly on the wheels caused problems with poor riding and did not work well with the springs. On Novelty, the cylinders were mounted vertically towards the rear of the engine. Directly below were bell cranks. Connecting rods linked the bell cranks to the crank axle; the valve gear took a similar route to the drive. One effect of this was it had links, resulting in lost motion.
The wheels themselves were of the suspension type. It is easy to think that Novelty is an 0-4-0 locomotive as it had equal sized wheels, however is an 0-2-2WT. Only the wheels under the firebox were driven, the other wheels were not connected to the drive, although they could be coupled by a chain'when necessary'. Novelty was the first tank locomotive; as one of the rules for the Rainhill Trials related to the weight of the engine without a tender, a special allowance had to be made for Novelty. Novelty was the crowd’s favourite to win the Trials; this may be because it looked like a steam carriage or it may be because it did not look like a typical colliery engine of the time. In the demonstration runs that took place on the first day of the trials, Novelty did no
The cylinder is the power-producing element of the steam engine powering a steam locomotive. The cylinder is made pressure-tight with a piston. Cylinders were cast in cast iron and in steel; the cylinder casting includes other features such as mounting feet. The last big American locomotives incorporated the cylinders as part of huge one-piece steel castings that were the main frame of the locomotive. Renewable wearing surfaces were provided by cast-iron bushings; the way the valve controlled the steam entering and leaving the cylinder was known as steam distribution and shown by the shape of the indicator diagram. What happened to the steam inside the cylinder was assessed separately from what happened in the boiler and how much friction the moving machinery had to cope with; this assessment was known as "engine performance" or "cylinder performance". The cylinder performance, together with the boiler and machinery performance, established the efficiency of the complete locomotive; the pressure of the steam in the cylinder was measured as the piston moved and the power moving the piston was calculated and known as cylinder power.
The forces produced in the cylinder moved the train but were damaging to the structure which held the cylinders in place. Bolted joints came loose, cylinder castings and frames cracked and reduced the availability of the locomotive. Cylinders may be arranged in several different ways. On early locomotives, such as Puffing Billy, the cylinders were set vertically and the motion was transmitted through beams, as in a beam engine; the next stage, for example Stephenson's Rocket, was to drive the wheels directly from steeply inclined cylinders placed at the back of the locomotive. Direct drive became the standard arrangement, but the cylinders were moved to the front and placed either horizontal or nearly horizontal; the front-mounted cylinders could be placed either outside. Examples: Inside cylinders, Planet locomotive Outside cylinders, GNR Stirling 4-2-2In the 19th and early 20th centuries, inside cylinders were used in the UK, but outside cylinders were more common in Continental Europe and the United States.
The reason for this difference is unclear. From about 1920, outside cylinders became more common in the UK but many inside-cylinder engines continued to be built. Inside cylinders give a more stable ride with less yaw or "nosing" but access for maintenance is more difficult; some designers used inside cylinders for aesthetic reasons. The demand for more power led to the development of engines with four cylinders. Examples: Three cylinders, SR Class V, LNER Class A4, Merchant Navy class Four Cylinders, LMS Princess Royal Class, LMS Coronation Class, GWR Castle Class On a two-cylinder engine the cranks, whether inside or outside, are set at 90 degrees; as the cylinders are double-acting this gives four impulses per revolution and ensures that there are no dead centres. On a three-cylinder engine, two arrangements are possible: cranks set to give six spaced impulses per revolution – the usual arrangement. If the three cylinder axes are parallel, the cranks will be 120 degrees apart, but if the centre cylinder does not drive the leading driving axle, it will be inclined, the inside crank will be correspondingly shifted from 120 degrees.
For a given tractive effort and adhesion factor, a three-cylinder locomotive of this design will be less prone to wheelslip when starting than a 2-cylinder locomotive. Outside cranks set at 90 degrees, inside crank set at 135 degrees, giving six unequally spaced impulses per revolution; this arrangement was sometimes used on three-cylinder compound locomotives which used the outside cylinders for starting. This will give evenly spaced exhausts. Two arrangements are possible on a four-cylinder engine: all four cranks set at 90 degrees. With this arrangement the cylinders act in pairs, so there are four impulses per revolution, as with a two-cylinder engine. Most four-cylinder engines are of this type, it is cheaper and simpler to use only one set of valve gear on each side of the locomotive and to operate the second cylinder on that side by means of a rocking shaft from the first cylinder's valve spindle since the required valve events at the second cylinder are a mirror image of the first cylinder.
Pairs of cranks set at 90 degrees with the inside pair set at 45 degrees to the outside pair. This gives eight impulses per revolution, it increases weight and complexity, by requiring four sets of valve gear, but gives smoother torque and reduces the risk of slipping. This was unusual in British practice but was used on the SR Lord Nelson class; such locomotives are distinguished by their exhaust beats, which occur at twice the frequency of a normal 2- or 4-cylinder engine. The valve chests or steam chests which contain the slide valves or piston valves may be located in various positions. If the cylinders are small, the valve chests may be located between the cylinders. For larger cylinders the valve chests are on top of the cylinders but, in early locomotives, they were sometimes underneath the cylinders; the valve chests are on top of the cylinders but, in older locomotives, the valve chests were sometimes located alongside the cylinders and inserted through slots in the frames. This meant that, while the cylinders were outside, the valves were inside a
Under the Whyte notation for the classification of steam locomotives by wheel arrangement, 4-6-0 represents the configuration of four leading wheels on two axles in a leading bogie, six powered and coupled driving wheels on three axles and no trailing wheels. In the mid 19th century, this wheel arrangement became the second most popular configuration for new steam locomotives in the United States of America, where this type is referred to as a Ten-wheeler; as a locomotive pulling trains of lightweight all wood passenger cars in the 1890-1920s, it was exceptionally stable at near 100 mph speeds on the New York Central's New York to Chicago Water Level Route and on the Reading Railroad's Camden to Atlantic City, NJ, line. As passenger equipment grew heavier with all steel construction, heavier locomotives replaced the Ten Wheeler. During the second half of the nineteenth and first half of the twentieth centuries, the 4-6-0 was constructed in large numbers for passenger and mixed traffic service.
A natural extension of the 4-4-0 American wheel arrangement, the four-wheel leading bogie gave good stability at speed and allowed a longer boiler to be supported, while the lack of trailing wheels gave a high adhesive weight. The primary limitation of the type was the small size of the firebox. In passenger service, it was superseded by the 4-6-2 Pacific type whose trailing truck allowed it to carry a enlarged firebox. Prussia and Saxonia however went directly to the 2-8-2 Mikado type. For freight service, the addition of a fourth driving axle created the 4-8-0 Mastodon type, rare in North America, but became popular on Cape gauge in Southern Africa; the 4-6-0T locomotive version was a far less common type. It was used for passenger duties during the first decade of the twentieth century, but was soon superseded by the 4-6-2T Pacific, 4-6-4T Baltic and 2-6-4T Adriatic types, on which larger fire grates were possible. During the First World War, the type was used on narrow gauge military railways.
In 1907, five 6th Class locomotives of the Cape Government Railways were sold to the 3 ft 6 in Benguela Railway. These included one of the Dübs-built locomotives of 1897 and two each of the Neilson and Company and Neilson and Company-built locomotives of 1897 and 1898. In the mid-1930s, in order to ease maintenance, modifications were made to the running boards and brake gear of the CFB locomotives; the former involved mounting the running boards higher, thereby getting rid of the driving wheel fairings. This gave the locomotives a much more American rather than British appearance. In April 1951, three Class NG9 locomotives were purchased from the South African Railways for the Caminhos de Ferro de Moçâmedes, they were placed in service on the Ramal da Chibía, a 600 mm gauge branch line across 116 kilometres from Sá da Bandeira to Chiange. The locomotives were observed dumped at the Sá da Bandeira shops by 1969 and the branch line itself was closed in 1970. In 1897, three Class 6 4-6-0 locomotives were ordered by the Cape Government Railways from Neilson and Company for use on the new Vryburg to Bulawayo line of the fledgling Bechuanaland Railway Company.
The line through Bechuanaland Protectorate was still under construction and was operated by the CGR on behalf of the BR at the time. The locomotives were returned to the CGR; the Finnish State Railways operated the Classes Hk1, Hk2, Hk3, Hk5, Hv1, Hv2, Hv3, Hv4, Hr2 and Hr3 locomotives with a 4-6-0 wheel arrangement. The Class Hk1, numbers 232 to 241, was built by Baldwin Locomotive Works in 1898; the ten Baldwin locomotives were designated H1 class. Numbers 291 to 300 and 322 to 333 were built by the Richmond Locomotive Works in 1900 and 1901; the 22 Richmond locomotives were designated H2 class and were nicknamed Big-Wheel Kaanari. One of them, no. 293, the locomotive that brought Lenin from exile in August–September 1917 prior to the Russian Revolution, was presented by Finland to the Soviet Union on 13 June 1957 and is preserved at the Finland Station in St. Petersburg, Russia. Another 100 of these locomotives were manufactured in Finland from 1903 to 1916, numbered in the range from 437 to 574 and designated H3 to H8 classes.
The Class Hk5 was numbered from 439 to 515. One, no. 497, is preserved at Haapamäki. The Class Hv1 was built from 1915 by Lokomo, they were nicknamed Heikki and were numbered 545 to 578 and 648 to 655. The class remained in service until 1967. One, no. 555 named Princess, is preserved at the Finnish Railway Museum. The Class Hv2 was built by Berliner Maschinenbau and Lokomo in the years between 1919 and 1926, they were numbered 579 to 593, 671 to 684 and 777 to 780. One, no. 680, is preserved at Haapamäki. The Class Hv3 was built by Berliner and Lokomo in the years from 1921 to 1941, they were numbered 638 to 647, 781 to 785 and 991 to 999. Three Class Hv3 locomotives were preserved, no. 781 at Kerava, no. 995 at Suolahti and no. 998 at Haapamäki. The Class Hv4 was built by Tampella and Lokomo in the years from 1912 to 1933 and were numbered 516 to 529, 742 to 751 and 757 to 760. Two, numbers 742 and 751, are preserved at Haapamäki; the Swedish State Railways sold its Class Ta and Tb locomotives to Finland in 1942.
At the time, they were not in traffic in Sweden and, since they were purchased by Finland, they were not considered as war assistance. The Class Ta was designat