Horsepower is a unit of measurement of power, or the rate at which work is done. There are many different types of horsepower. Two common definitions being used today are the mechanical horsepower, about 745.7 watts, the metric horsepower, 735.5 watts. The term was adopted in the late 18th century by Scottish engineer James Watt to compare the output of steam engines with the power of draft horses, it was expanded to include the output power of other types of piston engines, as well as turbines, electric motors and other machinery. The definition of the unit varied among geographical regions. Most countries now use the SI unit watt for measurement of power. With the implementation of the EU Directive 80/181/EEC on January 1, 2010, the use of horsepower in the EU is permitted only as a supplementary unit; the development of the steam engine provided a reason to compare the output of horses with that of the engines that could replace them. In 1702, Thomas Savery wrote in The Miner's Friend: So that an engine which will raise as much water as two horses, working together at one time in such a work, can do, for which there must be kept ten or twelve horses for doing the same.
I say, such an engine may be made large enough to do the work required in employing eight, fifteen, or twenty horses to be maintained and kept for doing such a work… The idea was used by James Watt to help market his improved steam engine. He had agreed to take royalties of one third of the savings in coal from the older Newcomen steam engines; this royalty scheme did not work with customers who did not have existing steam engines but used horses instead. Watt determined; the wheel was 12 feet in radius. Watt judged. So: P = W t = F d t = 180 l b f × 2.4 × 2 π × 12 f t 1 m i n = 32, 572 f t ⋅ l b f m i n. Watt defined and calculated the horsepower as 32,572 ft⋅lbf/min, rounded to an 33,000 ft⋅lbf/min. Watt determined that a pony could lift an average 220 lbf 100 ft per minute over a four-hour working shift. Watt judged a horse was 50% more powerful than a pony and thus arrived at the 33,000 ft⋅lbf/min figure. Engineering in History recounts that John Smeaton estimated that a horse could produce 22,916 foot-pounds per minute.
John Desaguliers had suggested 44,000 foot-pounds per minute and Tredgold 27,500 foot-pounds per minute. "Watt found by experiment in 1782 that a'brewery horse' could produce 32,400 foot-pounds per minute." James Watt and Matthew Boulton standardized that figure at 33,000 foot-pounds per minute the next year. A common legend states that the unit was created when one of Watt's first customers, a brewer demanded an engine that would match a horse, chose the strongest horse he had and driving it to the limit. Watt, while aware of the trick, accepted the challenge and built a machine, even stronger than the figure achieved by the brewer, it was the output of that machine which became the horsepower. In 1993, R. D. Stevenson and R. J. Wassersug published correspondence in Nature summarizing measurements and calculations of peak and sustained work rates of a horse. Citing measurements made at the 1926 Iowa State Fair, they reported that the peak power over a few seconds has been measured to be as high as 14.9 hp and observed that for sustained activity, a work rate of about 1 hp per horse is consistent with agricultural advice from both the 19th and 20th centuries and consistent with a work rate of about 4 times the basal rate expended by other vertebrates for sustained activity.
When considering human-powered equipment, a healthy human can produce about 1.2 hp and sustain about 0.1 hp indefinitely. The Jamaican sprinter Usain Bolt produced a maximum of 3.5 hp 0.89 seconds into his 9.58 second 100-metre dash world record in 2009. When torque T is in pound-foot units, rotational speed is in rpm and power is required in horsepower: P / hp = T / × N / rpm 5252 The constant 5252 is the rounded value of /; when torque T is in inch pounds: P
Railway electrification system
A railway electrification system supplies electric power to railway trains and trams without an on-board prime mover or local fuel supply. Electric railways use electric locomotives to haul passengers or freight in separate cars or electric multiple units, passenger cars with their own motors. Electricity is generated in large and efficient generating stations, transmitted to the railway network and distributed to the trains; some electric railways have their own dedicated generating stations and transmission lines but most purchase power from an electric utility. The railway provides its own distribution lines and transformers. Power is supplied to moving trains with a continuous conductor running along the track that takes one of two forms: overhead line, suspended from poles or towers along the track or from structure or tunnel ceilings. Both overhead wire and third-rail systems use the running rails as the return conductor but some systems use a separate fourth rail for this purpose. In comparison to the principal alternative, the diesel engine, electric railways offer better energy efficiency, lower emissions and lower operating costs.
Electric locomotives are usually quieter, more powerful, more responsive and reliable than diesels. They have an important advantage in tunnels and urban areas; some electric traction systems provide regenerative braking that turns the train's kinetic energy back into electricity and returns it to the supply system to be used by other trains or the general utility grid. While diesel locomotives burn petroleum, electricity can be generated from diverse sources including renewable energy. Disadvantages of electric traction include high capital costs that may be uneconomic on trafficked routes. Different regions may use different supply voltages and frequencies, complicating through service and requiring greater complexity of locomotive power; the limited clearances available under overhead lines may preclude efficient double-stack container service. Railway electrification has increased in the past decades, as of 2012, electrified tracks account for nearly one third of total tracks globally. Electrification systems are classified by three main parameters: Voltage Current Direct current Alternating current Frequency Contact system Third rail Fourth rail Overhead lines Overhead lines plus linear motor Four rail system Five rail systemSelection of an electrification system is based on economics of energy supply and capital cost compared to the revenue obtained for freight and passenger traffic.
Different systems are used for intercity areas. Six of the most used voltages have been selected for European and international standardisation; some of these are independent of the contact system used, so that, for example, 750 V DC may be used with either third rail or overhead lines. There are many other voltage systems used for railway electrification systems around the world, the list of railway electrification systems covers both standard voltage and non-standard voltage systems; the permissible range of voltages allowed for the standardised voltages is as stated in standards BS EN 50163 and IEC 60850. These take into account the number of trains drawing their distance from the substation. Increasing availability of high-voltage semiconductors may allow the use of higher and more efficient DC voltages that heretofore have only been practical with AC. 1,500 V DC is used in Japan, Hong Kong, Republic of Ireland, France, New Zealand, the United States. In Slovakia, there are two narrow-gauge lines in the High Tatras.
In the Netherlands it is used on the main system, alongside 25 kV on the HSL-Zuid and Betuwelijn, 3000 V south of Maastricht. In Portugal, it is used in Denmark on the suburban S-train system. In the United Kingdom, 1,500 V DC was used in 1954 for the Woodhead trans-Pennine route; the system was used for suburban electrification in East London and Manchester, now converted to 25 kV AC. It is now only used for the Wear Metro. In India, 1,500 V DC was the first electrification system launched in 1925 in Mumbai area. Between 2012-2016, the electrification was converted to 25 kV 50 Hz AC, the countrywide system. 3 kV DC is used in Belgium, Spain, the northern Czech Republic, Slovenia, South Africa, former Soviet Union countries and the Netherlands. It was used by the Milwaukee Road from Harlowton, Montana to Seattle-Tacoma, across the Continental Divide and including extensive branch and loop lines in Montana, by the Delaware, Lackawanna & Western Railroad in the United States, the Kolkata suburban railway in India, before it was converted to 25 kV 50 Hz AC. DC volt
The volt is the derived unit for electric potential, electric potential difference, electromotive force. It is named after the Italian physicist Alessandro Volta. One volt is defined as the difference in electric potential between two points of a conducting wire when an electric current of one ampere dissipates one watt of power between those points, it is equal to the potential difference between two parallel, infinite planes spaced 1 meter apart that create an electric field of 1 newton per coulomb. Additionally, it is the potential difference between two points that will impart one joule of energy per coulomb of charge that passes through it, it can be expressed in terms of SI base units as V = potential energy charge = J C = kg ⋅ m 2 A ⋅ s 3. It can be expressed as amperes times ohms, watts per ampere, or joules per coulomb, equivalent to electronvolts per elementary charge: V = A ⋅ Ω = W A = J C = eV e; the "conventional" volt, V90, defined in 1987 by the 18th General Conference on Weights and Measures and in use from 1990, is implemented using the Josephson effect for exact frequency-to-voltage conversion, combined with the caesium frequency standard.
For the Josephson constant, KJ = 2e/h, the "conventional" value KJ-90 is used: K J-90 = 0.4835979 GHz μ V. This standard is realized using a series-connected array of several thousand or tens of thousands of junctions, excited by microwave signals between 10 and 80 GHz. Empirically, several experiments have shown that the method is independent of device design, measurement setup, etc. and no correction terms are required in a practical implementation. In the water-flow analogy, sometimes used to explain electric circuits by comparing them with water-filled pipes, voltage is likened to difference in water pressure. Current is proportional to the amount of water flowing at that pressure. A resistor would be a reduced diameter somewhere in the piping and a capacitor/inductor could be likened to a "U" shaped pipe where a higher water level on one side could store energy temporarily; the relationship between voltage and current is defined by Ohm's law. Ohm's Law is analogous to the Hagen–Poiseuille equation, as both are linear models relating flux and potential in their respective systems.
The voltage produced by each electrochemical cell in a battery is determined by the chemistry of that cell. See Galvanic cell § Cell voltage. Cells can be combined in series for multiples of that voltage, or additional circuitry added to adjust the voltage to a different level. Mechanical generators can be constructed to any voltage in a range of feasibility. Nominal voltages of familiar sources: Nerve cell resting potential: ~75 mV Single-cell, rechargeable NiMH or NiCd battery: 1.2 V Single-cell, non-rechargeable: alkaline battery: 1.5 V. Some antique vehicles use 6.3 volts. Electric vehicle battery: 400 V when charged Household mains electricity AC: 100 V in Japan 120 V in North America, 230 V in Europe, Asia and Australia Rapid transit third rail: 600–750 V High-speed train overhead power lines: 25 kV at 50 Hz, but see the List of railway electrification systems and 25 kV at 60 Hz for exceptions. High-voltage electric power transmission lines: 110 kV and up Lightning: Varies often around 100 MV.
In 1800, as the result of a professional disagreement over the galvanic response advocated by Luigi Galvani, Alessandro Volta developed the so-called voltaic pile, a forerunner of the battery, which produced a steady electric current. Volta had determined that the most effective pair of dissimilar metals to produce electricity was zinc and silver. In 1861, Latimer Clark and Sir Charles Bright coined the name "volt" for the unit of resistance. By 1873, the British Association for the Advancement of Science had defined the volt and farad. In 1881, the International Electrical Congress, now the International Electrotechnical Commission, approved the volt as the unit for electromotive force, they made the volt equal to 108 cgs units of voltage
GCR Class 9N
The Great Central Railway Class 9N, classified A5 by the LNER, was a class of 4-6-2 tank locomotives designed by John G. Robinson for suburban passenger services, they were fitted with piston valves and Stephenson valve gear. The GCR built 21 locomotives at Gorton Works in three batches between 1911 and 1917, they ordered a fourth batch of ten from Gorton, but this was not built until after the 1923 Grouping, under which GCR became part of the newly formed London and North Eastern Railway. The LNER ordered a fifth batch of 13 to a modified design, incorporating reduced boiler mountings and detail differences, these were built by the outside contractors Hawthorn, Leslie & Co. during 1925–26. No. 5447 was withdrawn in 1942. In 1943, the others were allocated new numbers in the 9800–42 block, but these were not applied until 1946. Forty-three locomotives passed to British Railways in 1948, between 1948 and 1951 their numbers were increased by 60000; the class was divided into two parts in December 1948 as follows: A5/1, 69800-69829: Built at Gorton to Robinson's design A5/2, 69830-69842: Built by Hawthorn, Leslie with modifications by GresleyNone have been preserved.
A 7mm scale kit is available from MSC models. Fry, E. V. ed.. Locomotives of the L. N. E. R. Part 7: Tank Engines - Classes A5 to H2. Kenilworth: RCTS. ISBN 0-901115-13-4. Ian Allan ABC of British Railways Locomotives, 1948 edition, part 4, page 55; the Robinson A5 Pacific Tank Locomotives Steam Loco Class Information: LNER 4-6-2T Steam Loco Class Information: LNER 4-6-2T
Shildon is a town in County Durham, in England. The population taken at the 2011 Census was 9,976, it is situated 2 miles south east of Bishop Auckland, 11 miles north of Darlington, 13 miles from Durham, 23 miles from Sunderland and 30 miles from Newcastle upon Tyne. Shildon is part of the Bishop Auckland parliamentary constituency, represented since 2005 by Helen Goodman MP for the Labour Party; the name Shildon comes from the Old English word sceld, This translates as'shelf shaped hill' or'shield/refuge'. Another possibility is the Old English word syclfe meaning'shelf' and the suffix duri meaning'hill'; this refers to the town's location on a limestone escarpment. The earliest inhabitants of the area were most present from the Mesolithic period some 6,000 years ago. Although no evidence of settlement has been found in Shildon itself a small flint tool discovered in the nearby Brusselton area may be from this period. Roman expansion reached County Durham in the first century AD. Possible evidence of Roman infrastructure has been uncovered in the area such as Hagg's Lane which passes through Brusselton Wood.
Hagg's Lane formed part of the Roman road known as Dere Street. The first recorded reference to Shildon came during the Anglo-Saxon period in 821 AD when lands were granted to the church. At the dawn of the 19th century Shildon was a few houses on a cross road; the Industrial Revolution and the coming of the railways saw. In 1801 the population was recorded at being 100 people, their occupations were noted as being in coal mining and the growing textiles industry. In 1818 notice was given in the London Gazette'...that application is intended to be made to Parliament in the next session, for an Act for making and maintaining a'rail-way or tram-road from the River Tees, at or near Stockton, in the county of Durham', with Shildon listed as one of the towns on the planned route. John Dixon, assistant to George Stephenson recalled the town. ‘I have known Shildon for fifty years when there was not a house of any sort at New Shildon, much less a Mechanics Institute. When I surveyed the lines of the projected railway in 1821, the site of this New Shildon Works was a wet, swampy field – a place to find a snipe, or a flock of peewits.
Dan Adamson’s was the nearest house. A part of Old Shildon existed, but ‘Chapel Row’, a row of miner’s houses, was unbuilt or unthought of.’ The volume of coal being produced by coal mining outstripped the capacity of the traditional method of transporting coal, on horse-drawn wagon ways. Steam power was introduced through the use of static steam engines; these were, in turn. Coal would be pulled by static engines over Brusselton Incline into Shildon where the wagons would be attached to a locomotive; the population grew with this industrial expansion, the population rising from 115 in 1821, to 2,631 in 1841 up to 11,759 by the end of the century. Records show in 1851 the town had 26 uninhabited. Two years the value of property in the town was assessed at £11,269 and 10 shillings. Demand led to a passenger service beginning from the town on 27 September 1825; the first train, Locomotion No.1 began its journey outside the Mason's Arms public house. There is an argument. In the early stages of the Stockton and Darlington Railway, tickets were sold at the bar.
Between 1833 and 1841 the company hired a room in the pub for use as a booking office. The railway ran from its northern terminus at Shildon along 27 miles of track to its terminus at Stockton. Recruited to the railway by George Stephenson in 1824, Timothy Hackworth went on to become superintendent in 1825, he was charged with building locomotives for the company. Timothy Hackworth moved into Hackworth House with his family in 1831. There he supervised the construction of. In 1833 Hackworth renegotiated his contract with the Stockton and Darlington Railway to take over the works himself; this became the Soho Locomotive Building Company. Hackworth was in a partnership with Nicholas Downing in Shildon however the partnership was formally dissolved on 25 March 1837; the oldest part still surviving is the Soho Shed. The grade II listed building was built in 1826 as a warehouse for an iron merchant; the North Eastern Railway were the occupant from 1863 before becoming a paint shop for trains in the 1870s.
In the 20th century it was used as a boxing gym and rehearsal space for the Shildon Works Silver Band. The shed still has the remnants of a 19th-century heating system; the engine shed along with Hackworth House was refurbished in 1975. Near the Soho Shed, 110 metres to the east, are the grade. Constructed circa 1846/47 or circa 1856 depending on source; the system was used for the refuelling of locomotive tenders. Coal wagons would be hauled to the top of the coal drops where their bottom would open and the coal would fall down a chute into the engine waiting below. In this area stand the Black Boy Stables and out buildings; the grade II listed stables were built in the early 19th century at the point where the branch lines met from the Black Boy Colliery and Surtees Railway. Restored in the 1970s the stables were damaged by fire in 1985. However, a 2016 report disputes their being stables, it states that while they are "clearly not stables", it believes one was a plate layer's cabin. The use of the other "adjacent structures is still in some doubt".
Furthermore, the area has the Goods Shed and Parcel Office. It handled local freight distribution in Shildon from 1857; the Parcels Office looked after the move
GCR Class 1A
The Great Central Railway Class 1A, classified B8 by the LNER, was a class of 4-6-0 mixed traffic locomotives designed by John G. Robinson for fast goods, relief passenger and excursion services, they were known as the ‘Glenalmond Class’ and were a smaller wheeled version of Robinson’s earlier Sir Sam Fay express passenger class, which they resembled. The prototype was built at Gorton locomotive works, during 1913 and the remaining ten, one year later, they had the same design problems associated with the Sir Sam Fay class and were used on secondary passenger and freight services. None have been preserved. Boddy, M. G.. Fry, E. V. ed. Locomotives of the L. N. E. R. Part 2B: Tender Engines—Classes B1 to B19. Lincoln: RCTS. ISBN 0-901115-73-8
Electric current collectors are used by trolleybuses, electric locomotives or EMUs to carry electrical power from overhead lines or electrical third rails to the electrical equipment of the vehicles. Those for overhead wires are roof-mounted devices, those for third rails are mounted on the bogies, they have one or more spring-loaded arms that press a collector or contact shoe against the rail or overhead wire. As the vehicle moves, the contact shoe slides along the wire or rail to draw the electricity needed to run the vehicle's motor; the current collector arms are electrically conductive but mounted insulated on the vehicle's roof, side or base. An insulated cable connects the collector with the transformer or motor; the steel rails of the tracks act as the electrical return. Electric vehicles that collect their current from an overhead line system use different forms of one- or two-arm pantograph collectors, bow collectors or trolley poles; the current collection device presses against the underside of the lowest wire of an overhead line system, called a contact wire.
Most overhead supply systems are either DC or single phase AC, using a single wire with return through the grounded running rails. Three phase AC systems use a pair of overhead wires, paired trolley poles. Electric railways with third rails, or fourth rails, in tunnels carry collector shoes projecting laterally, or vertically, from their bogies; the contact shoe may slide on the bottom or on the side. The side running contact shoe is used against the guide bars on rubber-tired metros. A vertical contact shoe is used on ground-level power supply systems, stud contact systems and fourth rail systems. A pair of contact shoes was used on underground current collection systems; the contact shoe on a stud contact system is called a ski collector. The ski collector moves vertically to accommodate slight variations in the height of the studs. Contact shoes may be used on overhead conductor rails, on guide bars or on trolley wires. Most railways use three rails. TRUCK