A coupling or coupler is a mechanism, typically located at each end of a rail vehicle , that connects them together to form a train. The equipment that connects the couplers to the vehicles is the draft gear or draw gear , which must absorb the stresses of the coupling and the acceleration of the train.
98-532: Throughout the history of rail vehicles, a variety of coupler designs and types have been developed worldwide. Key design considerations include strength, reliability, easy and efficient handling, and operator safety. Automatic couplers engage automatically when the cars are pushed together. Modern versions not only provide a mechanical connection, but can also couple brake lines and data lines. Different countries use different types of couplers. While North American railroads and China use Janney couplers , railroads in
196-513: A lock system that lifts ships up 85 feet (26 metres) to the main elevation of the Panama Canal and down again. The original canal had a total of six steps (three up, three down) for a ship's passage. The total length of the lock structures, including the approach walls, is over 1.9 miles (3 km). The locks were one of the greatest engineering works ever to be undertaken when they opened in 1914. No other concrete construction of comparable size
294-460: A Confederate veteran of the American Civil War , invented the semi-automatic knuckle coupler in 1868. It automatically locks the couplers on cars or locomotives together without a rail worker having to get between the cars, and replaced the link and pin coupler , which was a major cause of railroad worker injuries and deaths. The locking pin that ensures Janney couplers remain fastened together
392-439: A bridle, above the coupler pocket. Usual practice was to have a drawhook fitted to only one of the mating couplers and train crews therefore carried spare drawhooks and drawhook pins on the locomotive. While automatic coupling is possible, this rarely happens and manual assistance is required during coupling. Uncoupling is done manually by lifting the drawhook by hand to release it. The coupler could be adapted to be compatible with
490-530: A construction locomotive named Little Bess . The Natal Government Railways (NGR), established in the Colony of Natal in 1875, followed suit and all locomotives and rolling stock acquired by that railway were equipped with Johnston couplers, beginning with the NGR Class K 2-6-0T in 1877. Likewise, in 1889, when the first locomotives were obtained by the newly established Netherlands-South African Railway Company in
588-408: A form that could be reliably coupled when the train was stationary. The Panama Canal mules , the locomotives used to guide the ships through the locks of the Panama Canal , have link and pin couplers and side buffers. This design was chosen so that these normally solo operating locomotives could be coupled to another locomotive in the event of a breakdown. On straight track, the link and pin coupler
686-501: A greater cargo capacity than the previous locks were capable of handling. There are twelve locks (six pairs) in total. A two-step flight at Miraflores and a single pair at Pedro Miguel lift ships from the Pacific up to Gatun Lake ; then a triple flight at Gatun lowers them to the Atlantic side. All three sets of locks are paired; that is, there are two parallel flights of locks at each of
784-501: A high risk of serious injury or death to crew members, who had to go between moving vehicles to guide the link into the coupler pocket during coupling. Johnston couplers gradually began to be replaced on the South African Railways from 1927, but not on narrow gauge rolling stock. All new Cape gauge locomotives and rolling stock acquired from that year were equipped with AAR knuckle couplers. Conversion of all older rolling stock
882-542: A horizontal gap and a vertical hole in the knuckle itself to accommodate, respectively, a link and a pin, to enable it to couple to vehicles which were still equipped with the older link-and-pin couplers. The knuckle coupler has withstood the test of time since its invention, with only minor changes: Bazeley Coupler 1905-1918 M.C.B. D Type established as the Universal M.C.B. Standard, Adopted 1915 Arthur James Bazeley (1872-1937), railway couplings inventor/design engineer;
980-706: A lighter build than the "Type D", and was marketed by the Amsted Corporation, parent of ASF, as the "Standard for the World". It is still the most-used knuckle coupler in the world. The modern Alliance coupler still uses the modern AAR-10 or 10A contour, but has a shorter thus weaker head length, and thus cannot be used on North American interchanged rolling stock. Manufacturers of modern "Type E", "Type F Interlock" and "Type H Tightlock" couplers include McConway & Torley , ASF , and Buckeye, also known as Columbus Castings . The external contour of Janney knuckle couplers
1078-503: A patent search under "Bazeley, railway couplings" or "Arthur James Bazeley, railway couplings patents" which have been drawn/filed and provided by Roger Bazeley-USA, MSTM, MSID, CHSRM Mineta Transportation Institute , Transportation Industrial Designer. A.J. Bazeley Railway Coupling, Construction/Design Improvements and Draft Rigging related patents include: US 1193222, US 124622, US 1932719, US 1518299, US 1932503, US 2235194, US 1932440 and others. National Malleable Castings in 1891 absorbed
SECTION 10
#17328549138511176-582: A possible replacement of the buffers and chain coupling on European railways. Unicoupler was developed by Knorr from West Germany in the 1970s, in parallel with a compatible counterpart, the Intermat coupler, by VEB Waggonbau Bautzen from East Germany. The Unicoupler/Intermat coupler can automatically couple two pneumatic lines and up to six electrical connections. This coupler is mechanically compatible with SA-3 and Willison couplers (but pneumatic and electrical connections must be done manually). The Unicoupler
1274-510: A rather finicky coupler; reportedly annoying to make open and close. Castle: an improvement on the Janney design, and a step towards the modern knuckle. Split Knuckle: a rarer type, which replaces the finger of the Knuckle (the little flap that actually links two knuckles together, one of the few moving parts) with one that has a cut out in the middle of it and a hole bored through it; this modification
1372-419: A right-hand thread on the other. In the center of the screw is the handle housing with a hinged ball handle attached. This turnbuckle style arrangement allows the vehicles to be pulled together by tightening the screw with the attached handle. Typically, the screw is tightened until there are two threads left next to the handle housing. A support is attached to the trunnion nut on the coupling link side to rest
1470-402: A ship of up to 10,000 tons to be safely stopped. However, given the precise control of ships made possible by the mules, it was very unlikely that these chains would ever be required. With many modern canal users weighing over 60,000 tons, and given the expense of maintaining them, the fender chains were reduced in number in 1976 and finally removed in 1980. Beyond this, the original design of
1568-523: A time. The traction force limit is typically 350 kN. Sometimes the Norwegian coupler is supplemented with auxiliary chains. The Norwegian coupler is also known as the Lloyd coupler named after its British manufacturer F.H. Lloyd & Co. Ltd near Wednesbury or as the meat chopper coupler named after the shape of the movable hook. The Norwegian coupler allows sharper curves than the buffer and chain coupler, which
1666-401: A train. Cross culverts branch off from these main culverts, running under the lock chambers to openings in the floors. There are fourteen cross culverts in each chamber, each with five openings; seven cross culverts from the sidewall main culverts alternate with seven from the center wall culvert. The water is moved by gravity and is controlled by huge valves in the culverts. Each cross culvert
1764-525: A usable length of 1,000 ft (305 m). These dimensions determine the maximum size of ships that can use the canal; this size is known as Panamax. The total lift (the amount by which a ship is raised or lowered) in the three steps of the Gatun locks is 85 ft (25.9 m); the lift of the two-step Miraflores locks is 54 ft (16 m). The single-step Pedro Miguel locks have a lift of 31 ft (9.4 m). The lift at Miraflores actually varies due to
1862-436: Is a coupler commonly used on narrow gauge railroads with tight curves. By swapping the pulling and pushing devices, the standard screw coupling used on standard gauge railroads became a center buffer coupling with one screw coupling on each side of the buffer. The screw couplers are connected to a compensating lever that pivots on a vertical trunnion on the center buffer rod, allowing an even distribution of tractive forces between
1960-628: Is a variation on the Janney coupler, introduced by Belgian engineer and entrepreneur Émile Henricot [ fr ] of Court-Saint-Étienne . It is used on certain EMUs of the National Railway Company of Belgium , including the Class 75 [ fr ] ). The Willison coupler was developed in the US in 1916 to address issues present in the Janney coupling. The Russian SA3 coupler works according to
2058-521: Is also known as AK69e. Maximum tonnage of a train that uses this type of coupler is about 6000 t. AK69e and Intermat adoption failure has been attributed to economic performance. Janney coupler Knuckle couplers are a semi-automatic form of railway coupling that allow rail cars and locomotives to be securely linked together without rail workers having to get between the vehicles. Originally known as Janney couplers (the original patent name) they are almost always referred to as Knuckles in
SECTION 20
#17328549138512156-479: Is also known as a buckeye coupler , notably in the United Kingdom, where some rolling stock (mostly for passenger trains) is fitted with it. Janney was a dry goods clerk and former Confederate Army officer from Alexandria, Virginia , who used his lunch hours to whittle from wood an alternative to the link and pin coupler. The term buckeye comes from the nickname of the US state of Ohio , the "Buckeye State" and
2254-605: Is also used on the 1,435 mm ( 4 ft 8 + 1 ⁄ 2 in ) standard gauge networks of Iran and on Malmbanan in Sweden for ore trains. Some 2 ft ( 610 mm ) gauge cane tramway vehicles in Queensland have been fitted with miniature Willison couplers. It was introduced on the 2 ft ( 610 mm ) narrow-gauge Avontuur Railway of the South African Railways in 1973. The SA3 coupler
2352-688: Is an advantage on narrow gauge railways where low speeds and reduced train loads allow a simpler system. The Norwegian coupler is found only on narrow gauge railways of 1,067 mm ( 3 ft 6 in ), 1,000 mm ( 3 ft 3 + 3 ⁄ 8 in ) or less in Great Britain and its former colonies. For example, it is used on the Isle of Man Railway , the Western Australian Government Railways , in Tanzania , on
2450-437: Is flipped over the top of the hook to secure it. The safety device may also be a chain with a ball-shaped weight at the end that is thrown over the hook to hold it in place. On railways where the rolling stock always face the same direction, the mechanical hook can be on one end of the wagon only. Not all Norwegian couplers are compatible with one another as they vary in height and width, and may or may not be limited to one hook at
2548-509: Is independently controlled. A lock chamber can be filled in as little as ten minutes. The gates separating the chambers in each flight of locks must hold back a considerable weight of water, and must be both reliable and strong enough to withstand accidents, as the failure of a gate could unleash a flood of water downstream. These gates range from 47 to 82 ft (14.33 to 24.99 m) high, depending on position, and are 7 ft (2.13 m) thick. The tallest gates are at Miraflores , due to
2646-478: Is much safer than the links before it. Janney coupler is like two curved human hand. With gooseneck couplers or offset shank couplers , the horizontal centerline of the coupler head is above the horizontal centerline of the coupler shank, or shaft, and the draw gear . This arrangement is designed for use with low-floor freight cars , to lift the coupler head high enough to match the couplers on other rolling stock. The large bogie boxvans for car parts , used on
2744-420: Is one of the strongest couplers in the world – maximum tonnage of a train that uses this type of coupler is about 8000 t – but provides only mechanical coupling. Adding automatic electrical and pneumatic connectivity is a complex challenge. There are many variations and brand names for these couplers. As of 2020 Construcciones y Auxiliar de Ferrocarriles is working on an automatic coupler based on SA3,
2842-537: Is still widespread in Western and Central Europe and in parts of Northern Africa, the Middle East and South Asia. The link-and-pin coupling was the original style of coupling used on North American railways. After most railroads converted to semi-automatic Janney couplers , the link-and-pin survived on forest railways . While simple in principle, the system suffered from a lack of standardisation regarding size and height of
2940-418: Is used to return the mules to their starting point and does not have racks except on the steep inclines between lock chambers. Traction is by electric power, supplied through a third rail laid below surface level on the land side. Each mule has a powerful winch ; these are used to take cables in or pay them out to keep the ship centered in the lock while moving it from chamber to chamber. A failure of
3038-489: Is used. Since the vertical curve between the straight track sections and the ramp between the lock chambers has a very small radius, the difference in height would be too great for a link and pin coupler, so the locomotives must be pushed through these sections uncoupled by using the side buffers. They have an extra high buffer plate to prevent the buffers from buffer-locking in tight vertical curves. The balance lever coupling, also central buffer coupling with two screw coupling,
Railway coupling - Misplaced Pages Continue
3136-660: Is withdrawn manually by a worker using the "cut lever", which is operated from either side of the railroad car and does not require the person to go between the cars. The only time the worker has to go between cars is after they have been securely coupled, to hook up the air lines for the pneumatic brakes , and the head-end power cables in the case of passenger cars . Modern Janney couplers typically mount to rail cars and locomotives via draw gear ; early Janney couplers often had transitional shanks which mounted into legacy link and pin coupler pockets, or bolted directly to steam locomotive headstocks . Knuckle couplers are used in
3234-646: The Zuid-Afrikaansche Republiek , they were fitted with Johnston couplers. Unlike the 2 ft ( 610 mm ) narrow gauge railways of the CGR, those of the NGR also made use of Johnston couplers. The first of these narrow gauge lines came into operation in 1906, when the first NGR Class N 4-6-2T locomotives entered service on the Weenen branch out of Estcourt . Coupling and uncoupling were done manually, which posed
3332-496: The Association of American Railroads (AAR) coupler, is also commonly known as a buckeye , knuckle , or Alliance coupler. The AAR/APTA TypeE, TypeF, and TypeH couplers are all compatible Janney couplers, but used for different rail cars (general freight, tank cars, rotary hoppers, passenger, etc.). The knuckle coupler or Janney coupler was invented by Eli H. Janney , who received a patent in 1873 ( U.S. patent 138,405 ). It
3430-698: The Ffestiniog Railway , on the Lynton and Barnstaple Railway , and on the Welsh Highland Railway , Two versions of radial coupler were used in South Africa. One, the Johnston coupler, commonly known as a bell link-and-pin coupler, was introduced in 1873 and is similar in operation to and compatible with link-and-pin couplers, but bell-shaped with a circular coupler face. The other, the bell-and-hook coupler,
3528-415: The Norwegian coupler . It is a radial coupler with a coupler pocket which is open at the top of the coupling face. Instead of a link and pins, it makes use of a drawhook which, upon coupling, slides over the drawhook pin in the coupler of the next vehicle in the train. To prevent the drawhook of the mating coupler from accidental uncoupling, the coupler bell is equipped with a drawhook guard, commonly known as
3626-713: The Victorian Railways , were fitted with gooseneck couplers for that reason. The Henricot coupler, a variation on the Janney coupler, was introduced by Belgian engineer and entrepreneur Émile Henricot [ fr ] of Court-Saint-Étienne . It is used on certain electric multiple units of the Belgian State Railways , including the NMBS/SNCB class 75. Janney was a dry goods clerk and former Confederate Army officer from Alexandria, Virginia , who used his lunch hours to whittle from wood an alternative to
3724-609: The link and pin coupler. The term Buckeye comes from the nickname of the US state of Ohio , the "Buckeye state" and the Ohio Brass Company which originally marketed the coupling. In 1893, satisfied that an automatic coupler could meet the demands of commercial railroad operations and, at the same time, be manipulated safely, the US Congress passed the Safety Appliance Act . Its success in promoting switch-yard safety
3822-485: The "Sharon Coupler" PAT APP Nov. 10, 1910, 1911,1913, 1914, the "Simplex Coupler" PAT APP May 3, 1903, the "Climax Coupler", the "Latrobe Coupler", the "Tower Coupler", the "Major Coupler", the " Gould Coupler ", the "Pitt Coupler", the "R.E. Janney Coupler", the "Kelso Coupler" and others. A.J. Bazeley related railway inventions, U.S. patents and railway coupler mechanical drawings and illustrations filed and assigned to National Malleable Castings Company can be referenced by
3920-490: The 1932 contour, though tolerances, metallurgy and machining techniques have improved, resulting in notable reductions in coupler slack. Type H tightlock couplings used on passenger stock have a variation of the 10A contour that nearly eliminates slack during normal operation and minimizes the possibility of " telescoping " during a derailment. The purpose of couplers is to join rail cars and locomotives to each other so they all are securely linked together. Major Eli Janney ,
4018-568: The 19th century by the assemblage known as the Miller platform , which included a new coupler called the Miller hook. The Miller platform (and hook coupler) was used for several decades before being replaced by the Janney coupler . The Norwegian coupler consists of a central buffer with a movable hook that drops into a slot in the central buffer. There may also be a U-shaped safety catch on the opposite buffer that
Railway coupling - Misplaced Pages Continue
4116-549: The Americas, Africa, Asia-Pacific, UK, Belgium and Spain (narrow gauge railway only). Among its features: Janney Type E double-shelf couplers are yet another variety, typical on North American hazardous material tank cars . The Janney coupler is commonly used on railway couplings, as it is strong and locks automatically. Janney coupler was patented by Eli Janney after the US Civil War . The Janney interlocking coupling system
4214-527: The Chicago Malleable Iron which was founded in 1873 by Alfred A. Pope and John C. Coonley, who operated similar companies in Ohio and Indiana. By the late 1880s, the company employed nearly 1,000 men at its 26th and Western Chicago works, which manufactured various railroad couplers and steel products for the railroad industries. In 1891, Chicago Malleable became part of the new National Malleable Castings Co.,
4312-621: The Cleveland-based company, where Arthur J. Bazeley was employed as a senior design engineer, had additional manufacturing plants across the Midwest. National Malleable purchased the Latrobe Steel & Coupler's plant in Melrose Park, Illinois , in 1909. In 1923, when it had begun to supply the automobile industry, the company changed its name to National Malleable & Steel Castings. Its stock
4410-563: The Janney "Type D" coupler, that was then made the MCB standard coupler for North America; new and rebuilt rolling stock had to be fitted with that coupler. That ended the market for knuckle couplers with proprietary components, excepting those exported from the US to other countries not complying with MCB standards. The Alliance coupler, named after the ASF-owned foundry in Alliance, Ohio , was developed as
4508-525: The Johnston coupler by replacing the drawhook with a U-shaped adapter link, which was attached using the same drawhook pin. Bell-and-hook couplers began to be replaced on the Avontuur Railway upon the introduction of Class 91-000 diesel-electric locomotives on the narrow gauge system in 1973. All new narrow gauge rolling stock acquired for that line from that year were equipped with Willison couplers . Older rolling stock were not converted and an adapter
4606-641: The M.C.B. The two couplers accepted were the Malleable Castings Company Bazeley Coupler , and the American Steel Foundries No.3 modified Alliance Coupler, out of nine couplers submitted to the committee as embodying the joint specification of design, The TYPE D coupler design based on The National Malleable Castings Bazeley Coupler patented designs and improvements was selected as the standard M.C.B Association's standard from 1918., after M.C.B. performance tested it along with
4704-875: The North American standard, there were 8,000 patented alternatives to choose from. Many AAR coupler designs exist to accommodate requirements of various car designs, but all are required to have certain dimensions in common which allow for one design to couple to any other. The Janney coupler is used in the United States , Canada , Mexico , Japan , India , Taiwan , Australia , New Zealand , South Africa , Saudi Arabia , Cuba , Chile , Brazil , Portugal , China and many countries in Africa both standard gauge and narrow gauges. The Janney coupler generally provides only mechanical coupling, only Type H adds automatic connections of pneumatic and electrical lines. The Henricot coupler
4802-570: The Ohio Brass Company which originally marketed the coupling. In 1893, satisfied that an automatic coupler could meet the demands of commercial railroad operations and, at the same time, be manipulated safely, the United States Congress passed the Safety Appliance Act . Its success in promoting switchyard safety was stunning. Between 1877 and 1887, approximately 38% of all railworker accidents involved coupling. That percentage fell as
4900-597: The Type C designs. The Type “D” Experimental Standard M.C.B. Coupler was unanimously recommended by the Master Car Builders Association and its Coupler Committee for adoption as the National/International (United States/Canadian) standard for coupler design and manufacturing specification uniformity by the M.C.B. Master Car Builders’ Association on June 15, 1916 after its 1915 Convention. This resulted in
4998-557: The US and Canada (regardless of their actual official model name, nowadays generally various AAR types in North America), but are also known as American , AAR , APT , ARA , MCB , Buckeye , tightlock (in the UK) or Centre Buffer Couplers . There are many variations of knuckle coupler in use today, and even more from the past, some variants of knuckle include: Janney: the American original,
SECTION 50
#17328549138515096-407: The bottom of the lock chambers, either hydraulically or by compressed air. The new dams were retired in the late 1980s, and today, no emergency dams are in place. Since all the lock equipment is operated electrically, the process of locking a ship up or down can be controlled from a central control room, which is located on the center wall of the upper flight of locks. The controls were designed from
5194-419: The chambers is 60 ft (18 m) thick and houses three galleries that run its full length. The lowest of these is a drainage tunnel; above this is a gallery for electrical cabling; and toward the top is a passageway that allows operators to gain access to the lock machinery. Each lock chamber requires 26,700,000 US gal (101,000 m ) of water to fill it from the lowered to the raised position;
5292-463: The consist (one or more cars coupled together) of cars is in compression; opposite of tension. The basic type of coupling on railways following the British tradition is the buffer and chain coupling. A large chain of three links connects hooks on the adjoining wagons. These couplings followed earlier tramway practice but were made more regular. Buffers on the frame of the wagon absorbed impact loads, as
5390-519: The coupler and its moving parts. In order to govern uniform standards for the interchangeability and the proper relation between fitting parts, the A.R.A. Committee on Couplers and draft gears designed and distributed templates, gauges, and master guides to assure the proper interchangeability and fitting of parts to maintain the proper operation of various multi-source manufactured railway couplers. Panama Canal locks#Mules The Panama Canal locks ( Spanish : Esclusas del Canal de Panamá ) are
5488-512: The decision by the Cape government to expand the railways into the interior and to convert the existing tracks from 4 ft 8 + 1 ⁄ 2 in ( 1,435 mm ) standard gauge to 3 ft 6 in ( 1,067 mm ) Cape gauge. All new Cape gauge locomotives and rolling stock acquired from 1873 were equipped with these or similar couplers, beginning with the CGR 0-4-0ST of 1873 ,
5586-645: The drain and filling the valves of a lock chamber simultaneously. The construction of the locks began with the first concrete laid at Gatun, on August 24, 1909, by the Philadelphia-based company Day & Zimmermann (formerly known as Dodge & Day). The Gatun locks are built into a cut made in a hill bordering the lake, which required the excavation of 5,000,000 cubic yards (3,800,000 cubic metres) of material, mostly rock. The locks themselves were made of 2,046,100 cu yd (1,564,000 m ) of concrete. The quantity of material needed to construct
5684-455: The early 1900s were less than 600 ft (183 m) long and therefore did not need the full length of the lock chamber. From the outset, it was considered an important safety feature that ships be guided through the lock chambers by electric locomotives, known as mulas ( mules , named after the animals traditionally used to cross the isthmus of Panama), running on the lock walls. These mules are used for side-to-side and braking control in
5782-411: The evolving heavier demands by US railways, as well as, National Malleable Castings' international customers in the United Kingdom, India, and many other countries building and expanding their railway systems. A.J. Bazeley was directly responsible for over 90 registered U.S. patents for railway automatic coupler improvements through design, under the coupler type names which included the "Buckeye coupler",
5880-555: The extreme tides on the Pacific side, between 43 ft (13 m) at extreme high tide and 64.5 ft (20 m) at extreme low tide; tidal differences on the Atlantic side are very small. The lock chambers are massive concrete structures. The side walls are from 45 to 55 ft (14 to 17 m) thick at the bases; toward the top, where less strength is required, they taper down in steps to 8 ft (2.4 m). The center wall between
5978-559: The formation of the Association of American Railroads (AAR) these were known as Master Car Builder (MCB) couplers. In 1934, the MCB was renamed as the AAR. Knuckle couplers of the 1880s and 1890s had a chaotic mixture of proprietary internal components, but all had the standard MCB external contour, making them compatible. There was a multitude of makes and models — Burns, Climax, Gould, Miller, Sharon and Tower. Some worked better than others. In 1913, American Steel Foundries (ASF) developed
SECTION 60
#17328549138516076-767: The former Soviet Union use SA3 couplers and the European countries use Scharfenberg and screw couplers . Challenges and complications arise when coupling vehicles with different couplers. Barrier cars , also called match cars , cars with dual couplers , or adapters are used to accomplish this task. Compatible and similar couplings or couplers are frequently referred to using widely differing make, brand, or regional names, or nicknames, which can make describing standard or typical designs confusing. Dimensions and ratings noted in these articles are usually of nominal or typical components and systems, though standards and practices also vary widely with railway, region, and era. Buff: when
6174-526: The handle of the screw to prevent loosening of the screw while the coupling is in use. The official name of this type of coupling is screw coupling or UIC coupling according to the European standard EN 15566 Draw gear and screw coupling . A simplified version of this, quicker to attach and detach, still used three links but with the centre link given a T-shaped slot. This could be turned lengthwise to lengthen it, allowing coupling, then turned vertically to
6272-429: The higher level of water to pass downstream. The additional gates are 70 ft (21 m) away from the operating gates. Originally the locks also featured chain barriers, which were stretched across the lock chambers to prevent a ship from running out of control and ramming a gate, and which were lowered into the lock floor to allow the ship to pass. These fender chains featured elaborate braking mechanisms to allow
6370-432: The large tidal range there. The heaviest leaves weigh 662 t (730 short tons; 652 long tons); the hinges themselves each weigh 16.7 t (36,817 lb). Each gate has two leaves, 65 ft (19.81 m) wide, which close to a "V" shape with the point upstream. This arrangement has the effect that the force of water from the higher side pushes the ends of the gates together firmly. The gates can be opened only when, in
6468-411: The links, and the size and height of the pockets. The link-and-pin coupler consisted of a tube-like body that received an oblong link. During coupling, a rail worker had to stand between the cars as they came together and guide the link into the coupler pocket. Once the cars were joined, the employee inserted a pin into a hole a few inches from the end of the tube to hold the link in place. This procedure
6566-447: The lock gates—for example, caused by a runaway ship hitting a gate—could unleash a flood on the lands downstream of the locks, as the lake above the locks ( Gatun Lake or Miraflores Lake ) drains through the lock system. Extra precaution against this is provided by doubling the gates at both ends of the upper chamber in each flight of locks; hence, there are always at least two gates in each flight of locks that would have to fail to allow
6664-445: The locks had yet another safety feature, emergency dams that could be swung across the locks at the upper end of every flight. These consisted of swinging bridges, from which girders were lowered to the lock floor; steel shutters could then be run down these girders to block the flow of water. Never used, they were removed in the 1950s. In the late 1930s, the original dams were replaced by new dams, which were raised out of slots in
6762-466: The locks required extensive measures to be put in place to handle the stone and cement. Stone was brought from Portobelo to the Gatun locks, while the work on the Pacific side used stone quarried from Ancon Hill. Huge overhead cableways were constructed to transport concrete into the construction at Gatun. 85 ft (26 m) high towers were built on the banks of the canal, and cables of 2.5 in (6 cm) steel wire were strung between them to span
6860-429: The locks, which are narrow relative to modern-day ships. Forward motion into and through the locks is actually provided by the ship's engines and not the mules. A ship approaching the locks first pulls up to the guide wall, which is an extension of the center wall of the locks, where it is taken under control by the mules on the wall before proceeding into the lock. As it moves forward, additional lines are taken to mules on
6958-405: The locks. Buckets running on these cables carried up to six tons of concrete at a time into the locks. Electric railways were constructed to take stone, sand, and cement from the docks to the concrete mixing machines, from where another electric railway carried two 6-ton buckets at a time to the cableways. The smaller constructions at Pedro Miguel and Miraflores used cranes and steam locomotives in
7056-423: The number of railroad employees steadily increased during that decade. When the Janney coupling was chosen to be the American standard, there were 8,000 patented alternatives to choose from. The only significant disadvantage of using the AAR (Janney) design is that sometimes the drawheads need to be manually aligned. During the transition period from link-and-pin couplers, knuckle couplers on many locomotives had
7154-429: The operating cycle, the water level on both sides is equal. The original gate machinery consisted of a huge drive wheel, powered by an electric motor, to which was attached a connecting rod, which in turn attached to the middle of the gate. The gates are hollow and buoyant, much like the hull of a ship, and are so well balanced that two 19 kW (25 hp) motors are enough to move each gate leaf. If one motor fails,
7252-418: The other can still operate the gate at reduced speed. All but one chamber contains a pair of auxiliary gates, which can be used to divide the chamber in two. This design allows for the transit of smaller vessels less than 600 ft (183 m) long, such as canal tugs, without using the full quantity of water. The auxiliary gates were originally incorporated because the overwhelming majority of all ships of
7350-429: The other wall. With large ships, there are two mules on each side at the bow, and two each side at the stern—eight in total, allowing for precise control of the ship. Mules are not used on the new expansion locks. The mules themselves run on paired 5 ft ( 1,524 mm ) broad gauge railway tracks. The track closest to the canal is used for towing and has rack tracks for geared operation . The track inland
7448-416: The outset to minimize the chance of operator error and include a complete model of the locks, with moving components that mirror the state of the real lock gates and valves. In this way, the operator can see exactly what state the locks and water valves are in. Mechanical interlocks are built into the controls to make sure that no component can be moved while another is in an incorrect state—for example, opening
7546-461: The railroads began to replace link and pin couplers with automatic couplers. By 1902, only two years after the SAA's effective date, coupling accidents constituted only 4% of all employee accidents. Coupler-related accidents dropped from nearly 11,000 in 1892 to just over 2,000 in 1902, even though the number of railroad employees steadily increased during that decade. When the Janney coupler was chosen to be
7644-437: The same amount of water must be drained from the chamber to lower it again. Embedded in the side and center walls are three large water culverts that are used to carry water from the lake into the chambers to raise them, and from each chamber down to the next, or to the sea, to lower them. These culverts start at a diameter of 22 ft (6.71 m) and reduce to 18 ft (5.49 m) in diameter, large enough to accommodate
7742-583: The same principles as the AAR coupler, but the two types are incompatible. It was introduced in the Soviet Union in 1932 based on a British patent and has since been used on the whole 1,520 mm ( 4 ft 11 + 27 ⁄ 32 in ) network, including Mongolia . Finnish locomotives have Unilink couplers that can couple to UIC couplers used in Finnish stock and SA3 couplers used in Russian stock. It
7840-564: The sharing of U.S. Patent improvements and agreed to by The National Malleable Castings Company, Henry Pope President; The Buckeye Steel Castings Company, The Gould Coupler Company , American Steel Foundries and The Monarch Steel Castings Company, and to be the active standard M.C.B. D Type forward from January 1, 1918. Buckeye Steel Castings Company was founded in 1881 as the Murray-Hayden Foundry before changing to The Buckeye Automatic Car Coupler Company and in 2002 after filing bankruptcy
7938-421: The shorter slot position, holding the wagons more tightly together. Higher speeds associated with fully-fitted freight made the screw-tensioned form a necessity. The earliest ' dumb buffers ' were fixed extensions of the wooden wagon frames, but later spring buffers were introduced. The first of these were stiff cushions of leather-covered horsehair, later steel springs and then hydraulic damping. This coupling
8036-407: The single-piece design, only minimal slack was possible. The system became quite popular with tram systems and narrow gauge lines. During the 1960s most cities replaced them with automatic couplers. But even in modern vehicles, Albert couplers get installed as emergency couplers for towing a faulty vehicle. The link and pin was replaced in North American passenger car usage during the latter part of
8134-572: The three lock sites. This, in principle, allows ships to pass in opposite directions simultaneously; however, large ships cannot cross safely at speed in the Culebra Cut , so in practice ships pass in one direction for a time, then in the other, using both "lanes" of the locks in one direction at a time. In this usage pattern, the paired locks offer redundancy during maintenance or in the event of mechanical issues. The lock chambers are 110 ft (33.53 m) wide by 1,050 ft (320 m) long, with
8232-430: The train overran a slowing locomotive. The simple chain could not be tensioned, and this loose coupling allowed a great deal of back and forth movement and bumping between cars, as well as jarring when trains started. While acceptable for mineral cars, this coupling made for an uncomfortable ride in passenger coaches, so the chain was improved by replacing the center link with a screw with a left-hand thread on one side and
8330-567: The two screw couplers. To avoid safety issues, Karl Albert, then director at the Krefeld Tramway , developed the Albert coupler during 1921. The Albert coupler was created as a key and slot coupler with two pins. Vehicles to be coupled were pushed together, both couplings moving to the same side. One pin was inserted, then the vehicles were pulled to straighten the coupling and the other pin inserted. This operation required less exact shunting. Due to
8428-585: Was amongst various inventors that made a multitude of improvements to the knuckle coupler; Beard's patents were U.S. patent 594,059 granted 23 November 1897, which then sold for approximately $ 50,000, and U.S. patent 624,901 granted 16 May 1899. In the UK, several versions of Janney couplers are fitted to a limited number of coaches, multiple units, wagons and locomotives. Janney Type E, Type F Interlock, and Type H tightlock couplings are compatible subtypes, each intended for specific rail car types. Prior to
8526-527: Was born in Bristol, England , in 1872, and worked for the Great Western Railway until the age of 34 when he immigrated to Cleveland, Ohio , in 1906, where he worked as a mechanical engineer for National Malleable Castings, Co., inventing and designing improvements in the function, strength, and durability of the (MCB/ARA/AAR/APTA) Janney, Knuckle, Alliance couplers and other coupling devices/ draw gear for
8624-477: Was designed to work with the older Link and Pin couplers in widespread use before, though could reasonably work with European style chain couplers too. AAR: AAR, the modern American knuckle, they have several variants of their own; ranging from the standard knuckle, to long drawbar ones, to passenger models, to a type designed specifically for tank cars. Janney couplers were first patented in 1873 by Eli H. Janney ( U.S. patent 138,405 ). Andrew Jackson Beard
8722-596: Was exceptionally dangerous and many brakemen lost fingers or entire hands when they did not get them out of the way of the coupler pockets in time. Many more were killed as a result of being crushed between cars or dragged under cars that were coupled too quickly. Brakemen were issued with heavy clubs that could be used to hold the link in position, but many brakemen would not use the club, and risked injury. The link-and-pin coupler proved unsatisfactory because: In Britain link-and-pin couplers were common on narrow gauge industrial and military railways, and eventually evolved into
8820-461: Was first introduced in the Cape of Good Hope in 1902, when two CGR Type A 2-6-4T locomotives were acquired as construction engines on the new 2 ft ( 610 mm ) narrow gauge Avontuur Railway which was being constructed out of Port Elizabeth through the Langkloof . In South Africa, these couplers were used on only the narrow gauge lines in the Cape of Good Hope. The coupler is similar to
8918-543: Was introduced in 1902 and is similar to the Norwegian coupler , but also with a circular coupler face and with a coupler pocket which is open at the top of the coupler face to accommodate the drawhook. The Johnston coupler, commonly known as a bell link-and-pin coupler from its bell shape, was first introduced in the Cape of Good Hope in 1873, following the establishment of the Cape Government Railways (CGR) in 1872 and
9016-507: Was listed on the New York Stock Exchange beginning in 1936 The National Malleable Castings Bazeley Coupler 1905-1918 M.C.B. D Type as Universal M.C.B. Standard Adopted 1915 At a joint M.C.B. Coupler Committee meeting on July 15, 1913, out of numerous studied competing railway coupler manufacturers and designs two couplers were selected for the new proposed universal U.S./Canadian coupler design standard, adopted, June 15, 1916 by
9114-596: Was reformed as Columbus Castings. Railway couplers were manufactured in accordance with the Standard Specifications of the AAR covering the purchase and acceptance of couplers, knuckles, locks and other working parts as shown in their "Mechanical Division Manual of Standards and Recommended Practice". Specifications as of March 1939 required that the fabrication casting material be of open hearth or electric furnace grade "B" steel with specific metallurgic requirements to insure proper tensile strength and reliability of
9212-409: Was stunning. Between 1877 and 1887, approximately 38% of all railworker accidents involved coupling. That percentage fell as the railroads began to replace link and pin couplers with automatic couplers. By 1902, only two years after the SAA's effective date, coupling accidents constituted only 4% of all employee accidents. Coupler-related accidents dropped from 11,710 in 1893 to 2,256 in 1902, even though
9310-630: Was the first aspect to be standardized by the MCB in the 1880s. Prior to this, there was a chaotic variety of constantly evolving and proprietary external contours and internal components. In 1893, manufacturers standardized on the MCB-5 or Type C contour, then in 1915 on the improved MCB-10 or Type D contour, and again in 1932 on the AAR-10A or Type E contour. The 1893, 1915, and 1932 contours are measurably different with slight dimensional changes that improved performance, yet remain compatible. Janney couplers still use
9408-434: Was to take several years and both coupler types could still be seen on some vehicles into the late 1950s. During the transition period, knuckle couplers on many locomotives had a horizontal gap and a vertical hole in the knuckle itself to accommodate, respectively, a link and a pin, to enable it to couple to vehicles which were still equipped with the older Johnston couplers. [REDACTED] The bell-and-hook coupling system
9506-615: Was undertaken until the Hoover Dam , in the 1930s. There are two independent transit lanes, since each lock is built double. The size of the original locks limits the maximum size of ships that can transit the canal; this size is known as Panamax . Construction on the Panama Canal expansion project , which included a third set of locks, began in September 2007, finished by May 2016 and began commercial operation on June 26, 2016. The new locks allow transit of larger, New Panamax ships, which have
9604-418: Was used to enable coupling between the two types. The drawhook on the bell-and-hook coupler would be replaced with the adapter, which was attached using the same drawhook pin. There are a number of automatic train couplings, most of which are mutually incompatible. The level of automation varies and can be divided into categories: The Janney coupler, later the Master Car Builders Association (MCB) coupler, now
#850149