Harp Switch Stand | |
---|---|
Classification | Railroad Switch |
Industry | Transportation |
Application | Intentional Path Deviation |
Components | Axle Pin |
Invented | 19th Century |
A harp switch stand is a type of railroad switch stand that was most common during the 19th century in the United States. The name derives from the characteristic shape of the stand. The harp stand was typically used in conjunction with the stub switch. It remained in use longest among narrow gauge railroads such as the Denver & Rio Grande well into the 20th century.
The harp mechanism was a simple lever which pivoted on an axle pin located midway up the main body (the "frame") of the stand. The upper part of the lever passed through a slot atop the stand. A signal target was usually attached at the top of the lever. The lower end of the lever extended below the main body of the stand where it attached to a bar. Pulling on the lever would pull this bar which in turn would move the rail into the desired position. The lever was sometimes secured by notches along the slot at the top of the stand. [1] [2] [3] Variations of this basic design were common.
Harp stands were of two types: a two-position and a three-position, for use with two-way and three-way turnouts, respectively.
A railroad switch (AE), turnout, or [set of] points (BE) is a mechanical installation enabling railway trains to be guided from one track to another, such as at a railway junction or where a spur or siding branches off.
A bicycle brake reduces the speed of a bicycle or prevents it from moving. The three main types are: rim brakes, disc brakes, and drum brakes.
A railway signal is a visual display device that conveys instructions or provides warning of instructions regarding the driver’s authority to proceed. The driver interprets the signal's indication and acts accordingly. Typically, a signal might inform the driver of the speed at which the train may safely proceed or it may instruct the driver to stop.
On a rail transport system, signalling control is the process by which control is exercised over train movements by way of railway signals and block systems to ensure that trains operate safely, over the correct route and to the proper timetable. Signalling control was originally exercised via a decentralised network of control points that were known by a variety of names including signal box, interlocking tower and signal cabin. Currently these decentralised systems are being consolidated into wide scale signalling centres or dispatch offices. Whatever the form, signalling control provides an interface between the human signal operator and the lineside signalling equipment. The technical apparatus used to control switches (points), signals and block systems is called interlocking.
A railway track or railroad track, also known as a train track, permanent way or simply track, is the structure on a railway or railroad consisting of the rails, fasteners, railroad ties and ballast, plus the underlying subgrade. It enables trains to move by providing a dependable surface for their wheels to roll upon. Early tracks were constructed with wooden or cast iron rails, and wooden or stone sleepers; since the 1870s, rails have almost universally been made from steel.
A railroad tie, crosstie, railway tie or railway sleeper is a rectangular support for the rails in railroad tracks. Generally laid perpendicular to the rails, ties transfer loads to the track ballast and subgrade, hold the rails upright and keep them spaced to the correct gauge.
Rail terminology is a form of technical terminology. The difference between the American term railroad and the international term railway is the most significant difference in rail terminology. These and other terms have often originated from the parallel development of rail transport systems in different parts of the world. In English-speaking countries outside the United Kingdom, a mixture of US and UK terms may exist.
This article is a glossary of the main components found on a typical steam locomotive.
In railway signalling, an interlocking is an arrangement of signal apparatus that prevents conflicting movements through an arrangement of tracks such as junctions or crossings. The signalling appliances and tracks are sometimes collectively referred to as an interlocking plant. An interlocking is designed so that it is impossible to display a signal to proceed unless the route to be used is proven safe.
A siding, in rail terminology, is a low-speed track section distinct from a running line or through route such as a main line, branch line, or spur. It may connect to through track or to other sidings at either end. Sidings often have lighter rails, meant for lower speed or less heavy traffic, and few, if any, signals. Sidings connected at both ends to a running line are commonly known as loops; those not so connected may be referred to as single-ended or dead-end sidings, or stubs.
The Walschaerts valve gear is a type of valve gear used to regulate the flow of steam to the pistons in steam locomotives, invented by Belgian railway engineer Egide Walschaerts in 1844. The gear is sometimes named without the final "s", since it was incorrectly patented under that name. It was extensively used in steam locomotives from the late 19th century until the end of the steam era.
Centralized traffic control (CTC) is a form of railway signalling that originated in North America. CTC consolidates train routing decisions that were previously carried out by local signal operators or the train crews themselves. The system consists of a centralized train dispatcher's office that controls railroad interlockings and traffic flows in portions of the rail system designated as CTC territory. One hallmark of CTC is a control panel with a graphical depiction of the railroad. On this panel, the dispatcher can keep track of trains' locations across the territory that the dispatcher controls. Larger railroads may have multiple dispatcher's offices and even multiple dispatchers for each operating division. These offices are usually located near the busiest yards or stations, and their operational qualities can be compared to air traffic towers.
Catch points and trap points are types of turnout which act as railway safety devices. Both work by guiding railway carriages and trucks from a dangerous route onto a separate, safer track. Catch points are used to derail vehicles which are out of control on steep slopes. Trap points are used to protect main railway lines from unauthorised vehicles moving onto them from sidings or branch lines. Either of these track arrangements may lead the vehicles into a sand drag or safety siding, track arrangements which are used to safely stop them after they have left the main tracks.
A railway detonator is a coin-sized device that is used as a loud warning signal to train drivers. It is placed on the top of the rail, usually secured with two lead straps, one on each side. When the wheel of the train passes over, it explodes, emitting a loud bang. It was invented in 1841 by English inventor Edward Alfred Cowper.
A derail or derailer is a device used to prevent fouling of a rail track by unauthorized movements of trains or unattended rolling stock. The device works by derailing the equipment as it rolls over or through it.
Mechanical railway signalling installations rely on lever frames for their operation to interlock the signals, track locks and points to allow the safe operation of trains in the area the signals control. Usually located in the signal box, the levers are operated either by the signalman or the pointsman.
The American Railway Engineering and Maintenance-of-Way Association (AREMA) is a North American railway industry group. It publishes recommended practices for the design, construction and maintenance of railway infrastructure, which are used in the United States and Canada.
Railway semaphore signal is one of the earliest forms of fixed railway signals. This semaphore system involves signals that display their different indications to train drivers by changing the angle of inclination of a pivoted 'arm'. Semaphore signals were patented in the early 1840s by Joseph James Stevens, and soon became the most widely used form of mechanical signal. Designs have altered over the intervening years, and colour light signals have replaced semaphore signals in most countries, but in a few they remain in use.
A rail fastening system is a means of fixing rails to railroad ties or sleepers. The terms rail anchors, tie plates, chairs and track fasteners are used to refer to parts or all of a rail fastening system. The components of a rail fastening system may also be known collectively as other track material, or OTM for short. Various types of fastening have been used over the years.
The Signals, Crane and Subway are heritage-listed railway infrastructure at Charters Towers railway station, Enterprise Road, Charters Towers, Charters Towers Region, Queensland, Australia. They were added to the Queensland Heritage Register on 30 October 2008.