|
Gresley Conjugated Valve Gear
The Gresley conjugated valve gear is a valve gear for steam locomotives designed by Sir Nigel Gresley, chief mechanical engineer of the LNER, assisted by Harold Holcroft. It enables a three-cylinder locomotive to operate with only the two sets of valve gear for the outside cylinders, and derives the valve motion for the inside cylinder from them by means of levers (the "2 to 1 lever" and "equal lever"). The gear is sometimes known as the Gresley-Holcroft gear, acknowledging Holcroft's major contributions to its development. Operation The Gresley conjugated gear is effectively an adding machine, where the position of the valve for the inside cylinder is the sum of the positions of the two outside cylinders, but reversed in direction. It can also be thought of as a rocking lever between one outside cylinder and the inside cylinder, as is common on 4-cylinder steam locomotives, but with the pivot point being moved back and forth by a lever from the other outside cylinder. If w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holcroft Valve Gear
The Holcroft valve gear was a type of conjugated valve gear designed and patented by Harold Holcroft and used on three-cylinder steam locomotives of the South Eastern & Chatham Railway (SECR). It bore many similarities to the Gresley conjugated valve gear, which it predated, as eventually used on all Gresley's three cylinder designs. It varied from the Gresley method of operation by using the combination lever assembly instead of the valve spindles to drive the middle cylinder of a three-cylinder design. This had operational advantages over Gresley's design, namely eliminating the problems of flexure, bush wear and the influence of heat in the valve spindles. Background Whilst working for the Great Western Railway at Swindon Works, Holcroft schemed out and patented (in 1909) a conjugated valve gear for three-cylinder steam locomotives, which allowed for the elimination of the valve gear for the inside cylinder by deriving the motion for the inside valve from that of the outside val ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NZR G Class (1928)
The NZR G class was a type of Garratt steam locomotive used in New Zealand, the only such Garratt type steam locomotives ever used by the New Zealand Railways (NZR). They were ordered to deal with traffic growth over the heavy gradients of the North Island Main Trunk (NIMT) and to do away with the use of banking engines on steep grades. They were one of the few Garratt designs to employ six cylinders. A mechanical stoker was used to feed coal into the locomotive. Introduction About 1913, General Manager E H Hiley considered the importing of 10 articulated Garratt engines and 10 Pacifics; however, with the success of the AB class and WAB class Pacifics no more was heard of Garratts. Then with the retirement in 1925 of the Chief Mechanical Engineer E E Gillon his successor G S Lynde invited Beyer, Peacock & Company of England to suggest a suitable Garrett for the NIMT, and they were then asked to quote for engines with either four or six cylinders. But the three six-cylinder e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rack And Pinion
A rack and pinion is a type of linear actuator that comprises a circular gear (the '' pinion'') engaging a linear gear (the ''rack''). Together, they convert rotational motion into linear motion. Rotating the pinion causes the rack to be driven in a line. Conversely, moving the rack linearly will cause the pinion to rotate. A rack and pinion drive can use both straight and helical gears. Though some suggest helical gears are quieter in operation, no hard evidence supports this theory. Helical racks, while being more affordable, have proven to increase side torque on the datums, increasing operating temperature leading to premature wear. Straight racks require a lower driving force and offer increased torque and speed per percentage of gear ratio which allows lower operating temperature and lessens viscal friction and energy use. The maximum force that can be transmitted in a rack and pinion mechanism is determined by the tooth pitch and the size of the pinion as well as the gear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New South Wales D58 Class Locomotive
The D58 class was a class of steam locomotives built by the New South Wales Government Railways in Australia. They were built with the 4-8-2 wheel arrangement. Design In 1943, approval was given for the New South Wales Government Railways Workshops to build 25 freight locomotives. The design was a modified version of the 57 class. The main alterations were the use of a rack and pinion valve gear in lieu of the Gresley 2:1 conjugated valve gear for the middle cylinder and the use of smaller cylinders to enable the locomotives to run to on the Main North line to Broadmeadow, a route which had a tighter loading gauge. They also used a Woodard divided drive of twin coupling rods between the second and third driving wheels. A valance was fitted over the valve gear on the front platform. Similarly to the earlier D57 class and the later AD60 class, the 58 class were fitted with a mechanical stoker to feed the large firebox Construction Eveleigh Railway Workshops built 11 locomotiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henschel & Son
Henschel & Son (german: Henschel und Sohn) was a German company, located in Kassel, best known during the 20th century as a maker of transportation equipment, including locomotives, trucks, buses and trolleybuses, and armoured fighting vehicles and weapons. Georg Christian Carl Henschel founded the factory in 1810 at Kassel. His son Carl Anton Henschel founded another factory in 1837. In 1848, the company began manufacturing locomotives. The factory became the largest locomotive manufacturer in Germany by the 20th century. Henschel built 10 articulated steam trucks, using Doble steam designs, for Deutsche Reichsbahn railways as delivery trucks. Several cars were built as well, one of which became Hermann Göring's staff car. In 1935 Henschel was able to upgrade its various steam locomotives to a high-speed Streamliner type with a maximum speeds of up to by the addition of a removable shell over the old steam locomotive. In 1918, Henschel began the production of gearboxes a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Victorian Railways H Class
The Victorian Railways H class was an express passenger steam locomotive operated by the Victorian Railways from 1941 to 1958. Intended to eliminate the use of double heading A2 class locomotives on ''The Overland'' services on the steeply graded Western line to Adelaide, wartime restrictions led to only one locomotive being built. Nicknamed ''Heavy Harry'', H220 was the largest locomotive ever built in Australia and the largest non-articulated steam locomotive to run on Australian railways. History By 1923, the A2 class 4-6-0 locomotives, which dated back to 1907, were frequently double-heading on interstate expresses to Serviceton and Albury, because increasing traffic saw loads exceed the eight-car maximum of a single A2. The Victorian Railways Commissioners recommended considerably more powerful locomotives, that could haul trains of up to eleven cars unassisted over the ruling gradients on those lines. The S class 4-6-2 Pacifics displaced the A2s from North East line ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roller Bearing
In mechanical engineering, a rolling-element bearing, also known as a rolling bearing, is a bearing which carries a load by placing rolling elements (such as balls or rollers) between two concentric, grooved rings called races. The relative motion of the races causes the rolling elements to roll with very little rolling resistance and with little sliding. One of the earliest and best-known rolling-element bearings are sets of logs laid on the ground with a large stone block on top. As the stone is pulled, the logs roll along the ground with little sliding friction. As each log comes out the back, it is moved to the front where the block then rolls on to it. It is possible to imitate such a bearing by placing several pens or pencils on a table and placing an item on top of them. See " bearings" for more on the historical development of bearings. A rolling element rotary bearing uses a shaft in a much larger hole, and cylinders called "rollers" tightly fill the space between t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4-8-2
Under the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of four leading wheels, eight powered and coupled driving wheels and two trailing wheels. This type of steam locomotive is commonly known as the Mountain type. Overview The Colony of Natal in South Africa and New Zealand were innovators of the Mountain wheel arrangement. The Natal Government Railways (NGR) placed in service the first tank engines with the 4-8-2 arrangement, and the NGR was also first to modify tender locomotives to use a 4-8-2 wheel arrangement. The New Zealand Railways Department (NZR) introduced the first tender locomotives designed and built as 4-8-2. In 1888, the Natal Government Railways placed the first five of its eventual one hundred Class D tank locomotives in service. The locomotive was designed by William Milne, the locomotive superintendent of the NGR from 1877 to 1896, and was built by Dübs & Company. This was the first known use of the whe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New South Wales D57 Class Locomotive
The D57 class was a class of 4-8-2 steam locomotives built by Clyde Engineering for the New South Wales Government Railways in Australia. The tenders were built by Mort's Dock. Introduction The locomotives were among the heaviest of locomotives in Australia with a axle load and this along with their width restricted their sphere of operation to Thirroul on the Illawarra line, Wallerawang on the Main Western line and Junee on the Main South line. Due to the immense size of the firebox, they could not be hand fired and had to use a mechanical stoker, thus becoming the first New South Wales locomotive class to use a mechanical stoker. They were later followed by the 58 class and the 60 class They were not permitted to operate on the Main Northern line due to load limitations on some bridges and a tighter loading gauge. They had the highest tractive effort of any conventional engines used in Australia and were of approximately equal capability to the modified 60 class Garratt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New South Wales Government Railways
The New South Wales Government Railways (NSWGR) was the agency of the Government of New South Wales that administered rail transport in New South Wales, Australia, between 1855 and 1932. Management The agency was managed by a range of different commission structures between 1857 and 1932, which reported to either the Minister for Public Works or the Minister for Transport. The inaugural Chief Commissioner was Ben Martindale and, following the enactment of the he became Commissioner of Railways. John Rae succeeded Martindale in 1861, and in 1877 Charles Goodchap was appointed Commissioner. The set up a corporate body of three railway commissioners to manage the railways and remove them from political influence, resulting in the resignation of Goodchap. This Board of Railway Commissioners of New South Wales was in place from 22 October 1888 to 4 April 1907, and was replaced by a sole Chief Commissioner of Railways and Tramways until 22 March 1932, when a panel arrangement ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> 4-8-2")
