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
North London Railway
The North London Railway company had lines connecting the north of London to the East and West India Docks in the east of the city. The main east to west route is now part of London Overground's North London Line. Other NLR lines fell into disuse but were revived as part of the Docklands Light Railway, the Overground's East London Line; the company was called the East & West India Docks & Birmingham Junction Railway from its inception in 1850, until 1853. It ceased operations in 1922; the East & West India Docks & Birmingham Junction Railway was incorporated by Act of Parliament on 26 August 1846. It was empowered to construct a railway from the district of Poplar and the docks to Camden Town in north London; the railway's headquarters and locomotive works were located in Bow. At first, it ran trains from Bow Junction on the London and Blackwall Railway to Islington, commencing on 26 September 1850; the line was extended to Camden Town railway station from 7 December 1850 and to Hampstead Road railway station from 9 June 1851.
Another extension via the L&BR was inaugurated on 1 January 1852, extending from Bow Junction to Poplar railway station, from there to Blackwall and the East India Docks. This arrangement lasted until 1865, when an extension from Dalston Junction to Broad Street was opened. In 1858 the line was extended along the North and South Western Junction Railway from Willesden Junction to a London and South Western Railway branch to Richmond. A bypass line from Camden to Willesden Junction via Gospel Oak and West Hampstead opened in 1860. Meanwhile, at the eastern end, a spur line connecting the NLR to Stratford from Victoria Park opened in 1854 but was not used by passenger services; the line between Camden Town and Dalston Junction was quadrupled in 1871. The LNWR took over the working of the railway on 1 February 1909; the company remained in existence until 1922, with its own board of directors and shareholders, when it was absorbed by the LNWR under The Railways Act, 1921. The last board meeting and last shareholders meeting were both held on 23 November 1922, the latter giving the shareholders' approval to the absorption.
The board minutes were signed by A Holland-Hibbert, the chairman, who added "Goodbye!". Beneath this was typed, "This was the last Board Meeting of the North London Railway Company, the Undertaking being absorbed under “The London and North Western Railway Preliminary Absorption Scheme 1922” by the London and North Western Railway Company as from 1 January 1922."The LNWR, which half-owned Broad Street station, was responsible for fourth-rail electrification of the Broad Street to Richmond and Kew Bridge services in 1916. The latter was cut as a wartime economy measure in 1940 and not resumed; the line from Dalston Junction to Poplar was damaged during the Blitz of World War II. Passenger services from Broad Street to Poplar via Victoria Park and Bow were suspended on 15 April 1944 and closed on 14 May 1944. A substitute bus service was provided until 23 April 1945 but the service was withdrawn at the end of the war. Passenger services from Dalston Junction to Victoria Park Junction resumed from 12 May 1980 during the gradual run-down of the line from Dalston Junction to Broad Street, which closed on 30 June 1986.
The line from Victoria Park Junction to Poplar Docks via Bow Junction closed on 3 October 1983. In 1979 the line between Richmond and Dalston via Gospel Oak and the extension to Stratford was joined with the former Eastern Counties and Thames Junction Railway to form the North London Line; the line between Willesden Junction and Camden via Primrose Hill is now used for empty coaching stock movements between the North London Line and Willesden Depot, freight trains and, during engineering work, diverted passenger services to and from the Watford DC Line. Primrose Hill station has been closed. Since 31 August 1987, Docklands Light Railway has followed the path of the North London Railway from Bow Church to Poplar; the northern section of the East Cross Route built in the late 1960s ran parallel to the rail line between Old Ford and Victoria Park stations, both of which were demolished for the road's construction. The East London Line Extension took over the abandoned stretch between Dalston Junction and Shoreditch from April 2010, incorporating it into the London Overground network.
Among the first locomotives bought by the railway from outside contractors were five 0-4-2ST saddle tanks. After that, all were constructed at London. List of locomotives LNWR electric units Bow railway works was built in 1853 and had a sizeable wagon repair shop; when the railway was merged into the LMS it was the smallest of 15 workshops. It repaired NLR locomotives and from 1927 those from the former London and Southend Railway. In the 1930s the works developed and manufactured the Hudd automatic control system for the LTSR, which led to a British Rail team from the national headquarters setting up in Bow to develop BR's standard Automatic Warning System; the workshop was badly damaged during the wagon workshop destroyed. In 1956 the workshop repaired diesel-electric locomotives for the motive power depot at Devons Road. After a while it was receiving locos in the morning and turning them round by the evening, which confused the statistical returns since locos were entering and leaving the works on the same day.
The works closed in 1960. Richmond to Willesden Junction
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, 0-6-0 represents the wheel arrangement of no leading wheels, six powered and coupled driving wheels on three axles and no trailing wheels. This was the most common wheel arrangement used on both tender and tank locomotives in versions with both inside and outside cylinders. In the United Kingdom, the Whyte notation of wheel arrangement was often used for the classification of electric and diesel-electric locomotives with side-rod coupled driving wheels. Under the UIC classification, popular in Europe, this wheel arrangement is written as C if the wheels are coupled with rods or gears, or Co if they are independently driven, the latter being electric and diesel-electric locomotives; the 0-6-0 configuration was the most used wheel arrangement for both tender and tank steam locomotives. The type was widely used for diesel switchers; because they lack leading and trailing wheels, locomotives of this type have all their weight pressing down on their driving wheels and have a high tractive effort and factor of adhesion, making them comparatively strong engines for their size and fuel consumption.
On the other hand, the lack of unpowered leading wheels have the result that 0-6-0 locomotives are less stable at speed. They are therefore used on trains where high speed is unnecessary. Since 0-6-0 tender engines can pull heavy trains, albeit the type was used to pull short and medium distance freight trains such as pickup goods trains along both main and branch lines; the tank engine versions were used as switching locomotives since the smaller 0-4-0 types were not large enough to be versatile in this job. 0-8-0 and larger switching locomotives, on the other hand, were too big to be economical or usable on built railways such as dockyards and goods yards the sorts of places where switching locomotives were most needed. The earliest 0-6-0 locomotives had outside cylinders, as these were simpler to construct and maintain. However, once designers began to overcome the problem of the breakage of the crank axles, inside cylinder versions were found to be more stable. Thereafter this pattern was adopted in the United Kingdom, although outside cylinder versions were widely used.
Tank engine versions of the type began to be built in quantity in the mid-1850s and had become common by the mid-1860s. 0-6-0 locomotives were amongst the first types to be used. The earliest recorded example was the Royal George, built by Timothy Hackworth for the Stockton and Darlington Railway in 1827. Other early examples included the Vulcan, the first inside-cylinder type, built by Charles Tayleur and Company in 1835 for the Leicester and Swannington Railway, Hector, a Long Boiler locomotive, built by Kitson and Company in 1845 for the York and North Midland Railway. Derwent, a two-tender locomotive built in 1845 by William and Alfred Kitching for the Stockton and Darlington Railway, is preserved at Darlington Railway Centre and Museum. For a steam tank locomotive, the suffix indicates the type of tank or tanks: 0-6-0T - side tanks 0-6-0ST - saddle tank 0-6-0PT - pannier tanks 0-6-0WT - well tankOther steam locomotive suffixes include 0-6-0VB - vertical boiler 0-6-0F - fireless locomotive 0-6-0G - geared steam locomotiveFor a diesel locomotive, the suffix indicates the transmission type: 0-6-0DM - mechanical transmission 0-6-0DH - hydraulic transmission 0-6-0DE - electric transmission All the major continental European railways used 0-6-0s of one sort or another, though not in the proportions used in the United Kingdom.
As in the United States, European 0-6-0 locomotives were restricted to switching and station pilot duties, though they were widely used on short branch lines to haul passenger and freight trains. On most branch lines, though and more powerful tank engines tended to be favoured. In New South Wales, the Z19 class was a tender type with this wheel arrangement, as was the Victorian Railways Y class; the Dorrigo Railway Museum collection includes seven Locomotives of the 0-6-0 wheel arrangement, including two Z19 class, three 0-6-0 saddle tanks and two 0-6-0 side tanks. Tank locomotives used by Finland were the VR Class Vr1 and VR Class Vr4; the VR Class Vr1s were numbered 530 to 544, 656 to 670 and 787 to 799. They had outside cylinders and were operational from 1913 to 1975. Built by Tampella and Hanomag, they were nicknamed Chicken. Number 669 is preserved at the Finnish Railway Museum; the Vr4s were a class of only four locomotives, numbered 1400 to 1423 built as 0-6-0s by Vulcan Iron Works, United States, but modified to 0-6-2s in 1951-1955, re-classified as Vr5.
Finland’s tender locomotives were the classes C1, C2, C3, C4, C5 and C6. The Finnish Steam Locomotive Class C1s were a class of ten locomotives numbered 21 to 30, they were operational from 1869 to 1926. They were nicknamed Bristollari. Number 21, preserved at the Finnish Railway Museum, is the second oldest preserved locomotive in Finland; the eighteen Class C2s were numbered 31 to 43 and 48 to 52. They were nicknamed Bristollari; the C3 was a class of only two locomotives, numbered 74 and 75. The thirteen Class C4s were numbered 62 and 78 to 89; the fourteen Finnish Steam Locomotive Class C5s were numbered 101 to 114. They were operational from 1881 to 1930, they were nicknamed Bliksti. No 110 is preserved at the Finnish Railway Museum; the C6 was a solitary class of one locomotive, numbered 100. In New Zealand the 0-6-0 design was restricted to tank engines; the Hunslet-built M class of 1874 and Y class of 1923 provided 7 examples
Stephenson valve gear
The Stephenson valve gear or Stephenson link or shifting link is a simple design of valve gear, used throughout the world for all kinds of steam engines. It was invented by his employees. During the 1830s the most popular valve drive for locomotives was known as gab motion in the U. K. and V-hook motion in the U. S. A; the gab motion incorporated two sets of rods for each cylinder. It was a clumsy mechanism, difficult to operate, only gave fixed valve events. In 1841 two employees in Stephenson’s locomotive works, draughtsman William Howe and pattern-maker William Williams, suggested the simple expedient of replacing the gabs with a vertical slotted link, pivoted at both ends to the tips of the eccentric rods. To change direction, the link and rod ends were bodily raised or lowered by means of a counterbalanced bell crank worked by a reach rod that connected it to the reversing lever; this not only simplified reversing but it was realised that the gear could be raised or lowered in small increments, thus the combined motion from the “forward” and “back” eccentrics in differing proportions would impart shorter travel to the valve, cutting off admission steam earlier in the stroke and using a smaller amount steam expansively in the cylinder, using its own energy rather than continuing to draw from the boiler.
It became the practice to start the engine or climb gradients at long cutoff about 70-80% maximum of the power stroke and to shorten the cutoff as momentum was gained to benefit from the economy of expansive working and the effect of increased lead and higher compression at the end of each stroke. This process was popularly known as "linking up" or “notching up”, the latter because the reversing lever could be held in precise positions by means of a catch on the lever engaging notches in a quadrant. A further intrinsic advantage of the Stephenson gear not found in most other types was variable lead. Depending on how the gear was laid out, it was possible to reduce compression and back pressure at the end of each piston stroke when working at low speed in full gear. American locomotives universally employed inside Stephenson valve gear placed between the frames until around 1900 when it gave way to outside Walschaerts motion. In Europe, Stephenson gear could be placed either outside the driving wheels and driven by either eccentrics or return cranks or else between the frames driven from the axle through eccentrics, as was the case in Great Britain.
Abner Doble considered Stephenson valve gear: " the most universally suitable valve gear of all, for it can be worked out for a long engine structure or a short one. It can be a simple valve gear and still be accurate, but its great advantage is that its accuracy is self-contained, for the exact relationship between its points of support have but little effect on the motion of the valve, its use on engines in which all the cylinders lie in one plane, represents, in the belief of the writer, the best choice." Another benefit of the Stephenson gear, intrinsic to the system, is variable lead: zero in full gear and increasing as cutoff is shortened. One consequent disadvantage of the Stephenson gear is that it has a tendency to over-compression at the end of the stroke when short cut-offs are used, therefore the minimum cut-off cannot be as low as on a locomotive with Walschaerts gear. Longer eccentric rods and a shorter link reduce this effect. Stephenson valve gear is a convenient arrangement for any engine that needs to reverse and was applied to railway locomotives, traction engines, steam car engines and to stationary engines that needed to reverse, such as rolling-mill engines.
It was used on the overwhelming majority of marine engines. The Great Western Railway used Stephenson gear on most of its locomotives, although the four-cylinder engines used inside Walschaerts gear. Details of the gear differ principally in the arrangement of the expansion link. In early locomotive practice, the eccentric rod ends were pivoted at the ends of the link while, in marine engines, the eccentric rod pivots were set behind the link slot; these became known as the'locomotive link' and the'launch link'. The launch link superseded the locomotive type as it allows more direct linear drive to the piston rod in full gear and permits a longer valve travel within a given space by reducing the size of eccentric required for a given travel. Launch-type links were pretty well universal for American locomotives right from the 1850s but, in Europe, although occurring as early as 1846, they did not become widespread until around 1900. Larger marine engines used the bulkier and more expensive marine double-bar link, which has greater wearing surfaces and which improved valve events by minimising geometric compromises inherent in the launch link.
In the United Kingdom, locomotives having Stephenson valve gear had this mounted in between the locomotive frames. In 1947, the London and Scottish Railway built a series of their Stanier Cl
Birkenhead Mollington Street TMD
Birkenhead Mollington Street was a former Traction Maintenance Depot located at Mollington Street in Birkenhead, England, on the Birkenhead Dock Branch railway. Although never directly connected by rail, the depot was situated less than 200 m from Birkenhead Central railway station; the depot serviced steam and subsequently diesel locomotives until 1985, when it was closed and demolished. As of 2018, the site of the depot is still disused; the Birkenhead Railway was formed on 1 August 1859 as a result of the Birkenhead and Cheshire Railway merging with the Chester and Birkenhead Railway. The new company was called the Birkenhead and Cheshire Junction Railway, but in 1859 shortened its name to The Birkenhead Railway. Taken over on 1 January 1860, it became a joint railway owned and operated by the London and North Western Railway and the Great Western Railway, becoming a joint railway; the new partners need new and better servicing facilities for their fleets, so built the new joint-depot in 1878.
The shed consisted of two separate but conjoined 8-road straight sheds: LNWR: to the north, an 8-road pitched-roof shed. Coaling stage to the west, turntable at the shed throat GWR: to the south and closest to the running lines, an 8-road north light pattern roofed shed. Coaling stage to the west, turntable to the south on an entrance siding. Coded BHD, it became 24 On nationalisation, the entire depot came under the control of British Railways London Midland Region, allocated code 6C. Steam locomotives stabled at the depot included: GWR 6800 Class. In 1951, the ex-LNWR shed was reduced in scale by half its width, to allow the construction of a new 2-road straight diesel shed in its place; the LNWR coal stage was removed. A new diesel fuelling stage was built on the entrance throat to the new diesel depot. Common sights in the 1950s were WD Austerity 2-8-0s and Stanier'Crab's, with six of the latter at the shed at any one time. Allocated shunters included Dock Tanks 47160, 47164 and 47166. In 1963 as the Beeching cuts were felt, the entire ex-GWR allocation of locos was removed and sent south to Swindon Works for reallocation or scrapping.
Nonetheless, up to ninety locomotives on shed could still be seen, on occasion. About half of these would be BR Standard Class 9F 2-10-0s, which worked the heavy iron ore trains from Bidston Dock to the John Summers steelworks in Shotton; the final day of steam operations at the shed was 5 November 1967. The depot code was 8H, between September 1963 and May 1973 and BC between May 1973 and closure, in 1985. After closure to steam, 9F duties were taken over by Brush Type 4s. During the final years of the depot, locomotives stabled included Class 03, Class 25, Class 40 and Class 47 traction. Class 03s were allocated to the depot. In the early 1980s, circa. 1984, during the Merseyrail changeover from Class 503 to Class 508 electric multiple units, those units were stored at the depot. The depot was closed on 25 November 1985, demolished in July 1987. Casserley, H. C.. Britain's Joint Lines. Littlehampton Book Services Ltd. ISBN 0711000247. OCLC 462185. Pearce, Kenn. Shed Side on Merseyside: The Last Days Of Steam.
Stroud: The History Press. ISBN 9780752460482. OCLC 751525501. Mitchell, Vic. Chester to Birkenhead. Middleton Press. Figs. 73-79. ISBN 9781908174215. OCLC 811323335. Photographic collection of steam locomotives at the shed