The vacuum brake is a braking system employed on trains and introduced in the mid-1860s. A variant, the automatic vacuum brake system, became universal in British train equipment and in countries influenced by British practice. Vacuum brakes enjoyed a brief period of adoption in the United States on narrow-gauge railroads, its limitations caused it to be progressively superseded by compressed air systems starting in the United Kingdom from the 1970s onward. The vacuum brake system is now obsolete. In the earliest days of railways, trains were slowed or stopped by the application of manually applied brakes on the locomotive and in brake vehicles through the train, by steam power brakes on locomotives; this was unsatisfactory, given the slow and unreliable response times and limited braking power that could be exerted, but the existing technology did not offer an improvement. A chain braking system was developed, requiring a chain to be coupled throughout the train, but it was impossible to arrange equal braking effort along the entire train.
A major advance was the adoption of a vacuum braking system, in which flexible pipes were connected between all the vehicles of the train, brakes on each vehicle could be controlled from the locomotive. The earliest scheme was a simple vacuum brake, in which vacuum was created by operation of a valve on the locomotive. Vacuum, rather than compressed air, was preferred because steam locomotives can be fitted with ejectors; the simple vacuum system had the major defect that in the event of one of the hoses connecting the vehicles becoming displaced the vacuum brake on the entire train was useless. In response to this obvious defect, the automatic vacuum brake was subsequently developed, it was designed to apply if the train became divided or if a hose became displaced, but opposition on the grounds of cost, to the fitting of the automatic type of brake, meant that it took a serious accident at Armagh in 1889 before legislation compelled the adoption of the automatic system. In this accident at Armagh, a portion of a train was detached from the locomotive on a steep gradient and ran away, killing 80 people.
The train was fitted with the simple vacuum brake, useless on the disconnected portion of the train. It was clear that if the vehicles had been fitted with an automatic continuous brake, the accident would certainly not have happened, the public concern at the scale of the accident prompted legislation mandating the use of a continuous automatic brake on all passenger trains. In continental Europe, the vacuum brake was sometimes called the Hardy brake, after John George Hardy of the Vacuum Brake Co, 7 Hohenstaufengasse, Vienna. In its simplest form, the automatic vacuum brake consists of a continuous pipe—the train pipe—running throughout the length of the train. In normal running a partial vacuum is maintained in the train pipe, the brakes are released; when air is admitted to the train pipe, the air at atmospheric pressure acts against pistons in cylinders in each vehicle. A vacuum is sustained on the other face of the pistons. A mechanical linkage transmits this force to brake shoes; the fittings to achieve this are: a train pipe: a steel pipe running the length of each vehicle, with flexible vacuum hoses at each end of the vehicles, coupled between adjacent vehicles.
The brake cylinder is contained in a larger housing—this gives a reserve of vacuum as the piston operates. The cylinder rocks in operation to maintain alignment with the brake rigging cranks, so it is supported in trunnion bearings, the vacuum pipe connection to it is flexible; the piston in the brake cylinder has a flexible piston ring that allows air to pass from the upper part of the cylinder to the lower part if necessary. When the vehicles have been at rest, so that the brake is not charged, the brake pistons will have dropped to their lower position in the absence of a pressure differential; when a locomotive is coupled to the vehicles, the driver moves the brake control to the "release" position and air is exhausted from the train pipe, creating a partial vacuum. Air in the upper part of the brake cylinders is exhausted from the train pipe, through a non-return valve. If the driver now moves his
A control car, control trailer or driving trailer is a generic term for a non-powered railroad or railway vehicle that can control operation of a train from the end opposite to the position of the locomotive. They can be used with Diesel or electric motive power, allowing push-pull operation without the use of an additional locomotive, they can be used with a power car or a railcar. In a few cases control cars were used with steam locomotives in Germany and France. In the United States, cab cars are control cars similar to regular passenger car, but with a full driver's compartment built into one or both ends, they can be similar to regular rail cars, to the point of including a gangway between cars so that they could be used in the middle of a passenger train like a regular car if necessary. European railways have used such equipment since the 1920s. In the United States they appeared for the first time in the 1960s. In the United Kingdom, driving trailers may have two driving cabs. Trains operating with a locomotive at one end and a control car at the other do not require the locomotive to run around to the opposite end of the train when reversing direction at a terminus.
Control cars can carry passengers, mail or a combination thereof, may, when used together with Diesel locomotives, contain an engine-generator set to provide head-end power. In addition to the driver's cab, which has all the controls and gauges necessary for remotely operating the locomotive, control cars have a horn, bell, or plough, all of the lights that would be on a locomotive, they must be fitted with all necessary communication and safety systems like GSM-R or European Train Control System. The classic control method was a multiple unit cable with jumpers between cars. In North America and Ireland a standard AAR 27-wire cable is used, in other countries cables with up to 61 wires can be found. A more recent method is to control the train through a Time-Division Multiplexed connection, which works with two wires; some commuter rail agencies in the United States use cab cars in place of regular passenger coaches on trains. However, with commuter agencies such as Metra, these cars make the train less aerodynamic.
The Chicago and North Western Railway had 42 control cabs built by Pullman-Standard in 1960, which eliminated the need for its trains or locomotives to be turned around. It was an outgrowth of multiple-unit operation, common on diesel locomotives of the time; the Canadian transit agency Exo uses control cars on all its trains, except its electric multiple units, which run as double-ended semi-permanently coupled three-car rakes. Amtrak has a number of ex-Budd Metroliner cab cars, which are used for push pull services on the Keystone Service and New Haven–Springfield Shuttle; the Long Island Rail Road uses cab cars on its C3 double deck coaches. During the mid-1990s, as push-pull operations became more common in the United States, cab-cars came under criticism for providing less protection to engine crews during level crossing accidents; this has been addressed by providing additional reinforcing in cab cars. This criticism became stronger after the 2005 Glendale train crash, in which a Metrolink train collided with a Jeep Grand Cherokee at a level crossing in California.
The train was traveling with its cab car in the front, the train jackknifed. Eleven people were killed in the accident, about 180 were injured. In early 2015, another collision occurred in Oxnard, involving one of Metrolink's improved "Rotem" cab cars at the front of the train hitting a truck at a crossing; the truck driver left his vehicle before the impact, but the collision resulted in multiple car derailments, jacknifing and the death of the engineer. From the 1970s until 1999, the Long Island Rail Road used a number of older locomotives converted to "power packs"; the original prime movers were replaced with 600 horsepower engines/generators for supplying HEP with the engineer's control stand left intact. Locomotives converted included Alco FA-1s and FA-2s, EMD F7s and one F9; the railroad has since switched to classic cab cars with a DM30AC locomotive on some trains. Longer trains require one on each end. Ontario's GO Transit had a similar program for EMD FP7s. MARC had a former F unit, #7100 converted into an APCU, or All-Purpose Control Unit.
It was rebuilt with a HEP generator, newer cab controls, fitted with a Nathan Airchime K5LA. Amtrak developed their Non-powered Control Unit by removing the prime mover, main alternator, traction motors from surplus EMD F40PH locomotives; the control stand was left in place, as were equipment allowing horn and headlight operation. A floor and roll-up side-doors were installed to allow for baggage service, leading to the nickname "cab-baggage cars" or "cabbages". Six NPCUs rebuilt for Cascades service in the Pacific Northwest do not have the roll-up side doors, because the Talgo sets on which they operate have a baggage car as part of the trainset, though #90230 was fitted with these doors. Four NPCUs are used on the Downeaster; these units have Downeaster logos applied to the sides of the units. Three NPCUs are designated for use on Amtrak California services, they are painted in a paint scheme similar to the old with blue-and-teal striped livery used by Caltrain between 1985 and 1997. In 2011, Amtrak F40PH 406 was converted to an NPCU to enable push-pull operation of Amtrak's 40th-anniversary exhibit train.
Unlike other NPCUs, the 406 retains its original number (instead of being r
2 ft and 600 mm gauge railways
Two foot and 600 mm gauge railways are narrow gauge railways with track gauges of 2 ft and 600 mm, respectively. Railways with similar, less common track gauges, such as 1 ft 11 3⁄4 in and 1 ft 11 1⁄2 in, are grouped with 2 ft and 600 mm gauge railways. Most of these lines are tourist lines, which are heritage railways or industrial lines, such as the Festiniog Railway in Wales and the Cripple Creek and Victor Narrow Gauge Railroad in Colorado. World War I trench railways produced the greatest concentration of 600 mm gauge railways to date. In preparation for World War II, the French Maginot Line and Alpine Line used 600 mm gauge railways for supply routes to the fixed border defenses. Australia has over 4,000 kilometres of 2 ft gauge sugar cane railway networks in the coastal areas of Queensland, which carry more than 30 million tonnes of sugarcane a year. Many 2 ft gauge and 600 mm gauge railways are used in amusement parks and theme parks worldwide; the interchange of rolling stock between these similar track gauges occurred.
The Otavi Mining and Railway Company in South-West Africa were transferred to the 2 ft gauge railways in South Africa and some surviving locomotives reside in Wales on the 1 ft 11 1⁄2 in gauge Welsh Highland Railway and the 1 ft 11 3⁄4 in gauge Brecon Mountain Railway. Decauville Heritage railway List of track gauges
A hose is a flexible hollow tube designed to carry fluids from one location to another. Hoses are sometimes called pipes, or more tubing; the shape of a hose is cylindrical. Hose design is based on a combination of performance. Common factors are size, pressure rating, length, straight hose or coilhose, chemical compatibility. Applications use nylon, polyethylene, PVC, or synthetic or natural rubbers, based on the environment and pressure rating needed. In recent years, hoses can be manufactured from special grades of polyethylene. Other hose materials include stainless steel and other metals. To achieve a better pressure resistance, hoses can be reinforced with a steel cord. Used reinforcement methods are braiding, spiraling and wrapping of fabric plies; the reinforcement increases the pressure resistance but the stiffness. To obtain flexibility, corrugations or bellows are used. Circumferential or helical reinforcement rings are applied to maintain these corrugated or bellowed structures under internal pressure.
Hoses can be used in water or other liquid environments. Hoses are used to carry fluids through air or fluid environments, they are used with clamps, spigots and nozzles to control fluid flow. Specific applications include the following: A garden hose is used to water plants in a garden or lawn, or to convey water to a sprinkler for the same purpose. A tough hose is used to water crops in agriculture for drip irrigation A fire hose is used by firefighters to convey water to the site of a fire. Air hoses are used in underwater diving to carry air from air tanks. Industrial uses for operating flexible machinery and worktable tooling such as pneumatic screw drivers, staplers, etc. Hoses have been used in air brake systems since the technology was invented by George Westinghouse in 1868; this includes: Railway air brake hoses used between locomotives and railroad cars, Truck air brake hoses used between tractors and semi-trailers Vacuum hoses Vacuum brake hoses have been used in Vacuum brake systems since the technology was invented in the mid-1860s Vacuum cleaners have corrugated flexible vacuum hoses to connect the cleaning head to the motor.
In building services, metal or plastic hoses are used to move water around a building. They can be used to take out vibration, thermal or settlement movement. Automotive hoses are used in automobiles to move fluids around for use in cooling, and/or hydraulics. Hoses are used to convey pressure or vacuum signals to control circuits or gauges, as well as conveying vacuum to heating, brake, and/or locking systems. In chemistry and medicine, hoses are used to move liquid gases around. A fuel hose carries fuel. In the oil industry high pressure hoses are used to move liquids under high pressures. Typical uses are for cement lines and Kelly hose; these are connected to either the choke manifold, cement manifold or standpipe manifold. In some cases, a rubber hose has been used as a weapon with; this is the origin of the term rubber-hose cryptanalysis. Cut-off factor Faucet Hose coupling, for joining one or more hoses or to equipment Pipe Tubing Bell, Sam. "How well do you know hoses?". Motor. No. February 2010.
Buffer (rail transport)
A buffer is a part of the buffers-and-chain coupling system used on the railway systems of many countries, among them most of those in Europe, for attaching railway vehicles to one another. Fitted at the ends of the vehicle frames, one at each corner, the buffers are projecting, shock-absorbing pads which, when vehicles are coupled, are brought into contact with those on the next vehicle; the draw chain used between each pair of vehicles includes a screw, tightened after coupling to shorten the chain and keep the buffers pressed together. Such is known as a'screw coupling'. Coupling chains were no more than that, a short length of heavy chain with no adjustment; these would result in a'loose-coupled train' in which the buffers of adjacent vehicles would only touch when the coupling chain was slack, such as when being pushed or going down hill. Although the buffers in the earliest days of railways were rigid, they soon came to be spring-loaded, while those fitted to modern locomotives and rolling stock incorporate oleo-pneumatic shock absorbers.
The original English buffers were the same on each side, so that there was a small tendency for buffers to slide off each other. German railway buffers are flat on one side and convex on the other to reduce this tendency to slide off. Dead-end sidings are fitted with buffer stops to prevent vehicles running off the end of the track; these may consist of a simple transverse beam fixed at buffer height but the buffer stops at passenger stations can be elaborate hydraulic installations capable of absorbing a considerable amount of energy. Friction buffer stops are clamped'loosely' to the rails, when hit by a train that fails to stop move with the train for 30 m scraping the top of the rails, which absorbs considerable energy. In violent collisions, the buffers of adjacent carriages may become displaced relative to one another, allowing the carriages to telescope, dangerous; the risk of this can be reduced if the buffers have corrugations that grip each other and prevent the buffers becoming displaced and so leading to telescoping
The Janney Coupler is a semi-automatic railway coupler. The earliest commercially successful version of the knuckle coupler, it was patented by Eli H. Janney in 1873. In the United Kingdom, where it is fitted to some rolling stock for passenger trains, it is known as a Buckeye Coupler originating from the coupler's manufacture as early as 1890 by the Buckeye Steel Castings firm in Columbus, Ohio, US; the AAR/APTA Type E, Type F, Type H tightlock couplers are all compatible knuckle couplers, but are employed on specific rail car types. Prior to the formation of the AAR these were known as MCB Couplers. In 1934 the MCB reconstituted itself into the AAR. Early knuckle couplers using a variety of proprietary head designs, but all using the most up-to-date MCB contour when cast, were the MCB, Tower, Climax, Burns, as many as 100 others. In 1913 the American Steel Foundries had developed the new Type "D" coupler, accepted as the standard coupler for the United States, no new equipment could be built using any other coupler.
This standard design ended the market for couplers with a proprietary head design, which were common in the MCB days, to all but those exported from the US to other countries not governed by the AAR standards. The Alliance coupler, named after the ASF-owned foundry in Alliance, was developed as a lighter build than the AAR Type "D" coupler, was marketed by the Amsted Corporation, the parent corporation of ASF, as the "Standard Coupler for the World", it is still the most used knuckle coupler in the world. The modern Alliance coupler still uses the modern AAR-10 and/or -10A contour, as well as others, but cannot be used in the US for "interchange" rolling stock Brand names of the now standard AAR Type "E", "F" and "Tightlock" couplers are ASF, McConway & Torley; the Interlocking contour of knuckle couplers was the first aspect to be standardized. In the MCB years, prior to about 1910, as early as the first Janney in 1873, there were many proprietary "head" designs, many MCB standard contours, which were evolving and changing every few years.
In about 1910 the producers were all using the standardized MCB-10 contour, soon to become the AAR-10. In the 1930s the AAR Type "D" was improved and became the Type "E". A few years the 10 contour was modified into a optional standard called the 10A contour; the most modern contour, for a plain Type "E" knuckle coupler, is still the AAR-10 and -10A, which are indistinguishable from the 1910 era MCB-10 contour. The same MCB-10 contour has been an approved standard for interchange service for over 100 years, with only the slightest dimensional changes; the Type "H" "Tightlock" couplers, which are used on passenger-carrying rolling stock use slight revisions to the old 10A contour. The purpose of couplers is to join rail cars and/or locomotives to each other so they all are securely linked together. Major Eli Janney, a Confederate veteran of the 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, replaced the "link and pin" coupler, a major cause of injuries to railroad workers.
The locking pin that ensures Janney couplers remain fastened together is withdrawn manually by a worker using the "cut lever", 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, the head-end power cables in the case of passenger cars. Janney couplers are attached to draw gear, but sometimes, in the case of locomotives, the Type "E" is bolted directly on the headstock; the Janney coupler is used in Canada, the United States, Japan, New Zealand, South Africa, Saudi Arabia, Chile, China and North Korea, elsewhere. Among its features: Maximum tonnage as high as 32,000 metric tons such as on the Fortescue Railway. Minimum ultimate tensile strength: Grade E knuckles: 650,000 pounds-force Grade C or Grade E knuckles are required for interchange service. Grade E coupler bodies: 900,000 pounds-force Several Janney coupler types exist to accommodate various cars, but all are required to have certain common dimensions allowing for compatibility.
Lighter weight railways, notably narrow gauge lines with no need for interchange, sometimes use smaller versions of the Janney MCB coupler. Such as Victorian narrow gauge lines. Janney couplers are always right-handed, i.e. their shape resembles the human right hand with fingers curled, as viewed from above. Required coupler heights, in North AmericaEmpty cars: 33.5 inches ± 1-inch Loaded cars: 32.5 inches in ± 1-inch Janney couplers are uncoupled by lifting the pin with a lever at the corner of the car. This pin is locked when the coupler is under tension, so the usual uncoupling steps are to compress the coupling with a locomotive and hold up the pin pull the cars apart. Side operated. Janney couplers are Bottom-Operated on Wagons and Top-Operated on Locomotives per AAR standards. Trains fitted with Janney couplers can accommodate heavier loads than any other type of coupler. Thus, the heaviest