A sandbox is a container on most locomotives, multiple units and trams that holds sand, which is dropped on the rail in front of the driving wheels in wet and slippery conditions and on steep grades to improve traction.
A sandbox is a container on most locomotives, multiple units and trams that holds sand, which is dropped on the rail in front of the driving wheels in wet and slippery conditions and on steep grades to improve traction.
The sand may be delivered by gravity, by a steam-blast (steam locomotives) or by compressed air. Gravity sanding requires that the sand be dry so that it runs freely. Locomotives use multiple sandboxes, so that their delivery pipes could be short and nearly vertical. Engine sheds in the UK were equipped with sand drying stoves, so that sandboxes could be refilled each morning with dry sand. Steam locomotives in the US had a single sandbox, called a sand dome, atop the boiler where the rising heat helped to dry the sand. Even with this arrangement, sand pipes tended to clog, and by the 1880s, pneumatic sanding systems were being proposed. [1]
The development of steam sanding was influential on locomotive design. As the sand could then be blown horizontally and directly under the wheels, it was no longer blown away by cross-winds before it could be effective. This prompted a resurgence of interest in some older single-driver locomotive designs, that had previously been limited by their adhesion performance. The development of Holt's steam sanding gear on the Midland Railway in 1886 prompted Johnson to design his successful 'Spinners' of 1887, twenty-one years after the previous Singles. These 'modern Singles' would continue in production for a further sixteen years on a number of British railways, [2] including the Great Eastern, Great Western, Great Central and Great Northern, and a famous single example, number 123 on the Caledonian Railway, which remained in main-line service until 1935. [3]
On diesel and electric locomotives and railcars, sandboxes are fitted close to the wheels so as to achieve the shortest possible length of delivery pipe. [4] Depots may have a sand drier installed to warm and to dry the sand before it is used. [5]
Braking sand scattered at a low speed can cause an isolating effect between the wheel and the rail in the case of individually driven traction vehicles. The Federal Railway Authority in Germany instructed the railway companies to avoid sanding at speeds of 25 km/h (16 mph) (or less) on disc-braked locomotives. [6] [ circular reference ]
In its report of 20 August 2013, the ARD magazine Report [7] mentions near misses when the use of brake sand interfered with the electrical contact between wheel and rail, thereby overriding train control systems. For this reason, the Swiss Federal Railways do not permit sanding for braking locomotives [8] [ circular reference ].
On August 1, 2013, there was a near-collision between two S-Bahn trains at Mainz Main Station. On September 24, 2013, the Federal Railway Authority announced that the cause was too much brake sand on the tracks. [9] [ circular reference ]
If too much sand is applied, it can lead to problems, especially at the track points or level crossings, where the sand cannot slip sideways. Lastly, the sand increases the friction between rail and wheel flange, which counteracts the wheel flange lubrication; the reduced wheel flange lubrication increases the danger of the wheels climbing up the rail.
A bogie is a chassis or framework that carries a wheelset, attached to a vehicle—a modular subassembly of wheels and axles. Bogies take various forms in various modes of transport. A bogie may remain normally attached or be quickly detachable. It may include a suspension component within it, or be solid and in turn be suspended ; it may be mounted on a swivel, as traditionally on a railway carriage or locomotive, additionally jointed and sprung, or held in place by other means.
A locomotive or engine is a rail transport vehicle that provides the motive power for a train. If a locomotive is capable of carrying a payload, it is usually rather referred to as a multiple unit, motor coach, railcar or power car; the use of these self-propelled vehicles is increasingly common for passenger trains, but rare for freight trains.
A rack railway is a steep grade railway with a toothed rack rail, usually between the running rails. The trains are fitted with one or more cog wheels or pinions that mesh with this rack rail. This allows the trains to operate on steep grades above 10%, which is the maximum for friction-based rail. Most rack railways are mountain railways, although a few are transit railways or tramways built to overcome a steep gradient in an urban environment.
A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material to heat water in the locomotive's boiler to the point where it becomes gaseous and its volume increases 1,700 times. Functionally, it is a steam engine on wheels.
In railway engineering, the term tractive effort describes the pulling or pushing capability of a locomotive. The published tractive force value for any vehicle may be theoretical—that is, calculated from known or implied mechanical properties—or obtained via testing under controlled conditions. The discussion herein covers the term's usage in mechanical applications in which the final stage of the power transmission system is one or more wheels in frictional contact with a railroad track.
Rail transport terms are a form of technical terminology applied to railways. Although many terms are uniform across different nations and companies, they are by no means universal, with differences often originating from parallel development of rail transport systems in different parts of the world, and in the national origins of the engineers and managers who built the inaugural rail infrastructure. An example is the term railroad, used in North America, and railway, generally used in English-speaking countries outside North America and by the International Union of Railways. In English-speaking countries outside the United Kingdom, a mixture of US and UK terms may exist.
Main components found on a typical steam locomotive include:
In rail transport, a derailment is a type of train wreck that occurs when a rail vehicle such as a train comes off its rails. Although many derailments are minor, all result in temporary disruption of the proper operation of the railway system and they are a potentially serious hazard.
The Pennsylvania Railroad's S2 class was a steam turbine locomotive designed and built in a collaborative effort by Baldwin Locomotive Works and Westinghouse Electric & Manufacturing Company, as an attempt to prolong the dominance of the steam locomotive by adapting technology that had been widely accepted in the marine industry. One was built, #6200, delivered in September 1944. The S2 was the sole example of the 6-8-6 wheel arrangement in the Whyte notation, with a six-wheel leading truck keeping the locomotive stable at speed, eight powered and coupled driving wheels, and a six-wheel trailing truck supporting the large firebox. The S2 used a direct-drive steam turbine provided by the Westinghouse Electric & Manufacturing Company, geared to the center pair of axles with the outer two axles connected by side rods; the fixed gear ratio was 18.5:1. Such design was to prevent energy loss and S2 achieved a mechanical efficiency of 97% which means only 3% of steam energy was lost within the propulsion equipment. The disadvantage of a direct-drive steam turbine was that the turbine could not operate at optimal speeds over the locomotive's entire speed range. The S2 was the largest, heaviest and fastest direct-drive turbine locomotive design ever built.
The Meigs Elevated Railway was an experimental but unsuccessful 19th century elevated steam-powered urban rapid transit system, often described as a monorail but technically pre-electric third rail. It was invented in the US by Josiah Vincent Meigs, of Lowell, Massachusetts, and was demonstrated from 1886 to 1894 in a suburb of Boston called East Cambridge.
An adhesion railway relies on adhesion traction to move the train, and is the most widespread and common type of railway in the world. Adhesion traction is the friction between the drive wheels and the steel rail. Since the vast majority of railways are adhesion railways, the term adhesion railway is used only when it is necessary to distinguish adhesion railways from railways moved by other means, such as by a stationary engine pulling on a cable attached to the cars or by a pinion meshing with a rack.
A road–rail vehicle or a rail–road vehicle is a dual-mode vehicle which can operate both on rail tracks and roads. They are also known as two-way vehicles, hi-rail, and rail and road vehicles.
Traction, traction force or tractive force is a force used to generate motion between a body and a tangential surface, through the use of either dry friction or shear force. It has important applications in vehicles, as in tractive effort.
Slippery rail, or low railhead adhesion, is a condition of railways (railroads) where contamination of the railhead reduces the traction between the wheel and the rail. This can lead to wheelslip when the train is taking power, and wheelslide when the train is braking. One common cause of contamination is fallen leaves that adhere to the railhead of railway tracks. The condition results in significant reduction in friction between train wheels and rails, and in extreme cases can render the track temporarily unusable. In Britain, the situation is colloquially referred to as "leaves on the line".
Wheel slide protection and wheel slip protection are railway terms used to describe automatic systems used to detect and prevent wheel-slide during braking or wheel-slip during acceleration. This is analogous to ABS and traction control systems used on motor vehicles. It is particularly important in slippery rail conditions.
Locomotive wheelslip is an event that affects railway motive power usually when starting from stationary, but can also affect an engine in motion.
The South African Railways Class GA 2-6-0+0-6-2 of 1921 was an articulated steam locomotive.
Rail squeal is a screeching train-track friction sound, commonly occurring on sharp curves.
Steam springs or steam suspension are a form of suspension used for some early steam locomotives designed and built by George Stephenson. They were only briefly used and may have been used for fewer than ten locomotives.
The MÁV class 601 is a class of Hungarian four cylinder Mallet -type locomotives, which was designed to haul long and very heavy cargo on very steep railway tracks. With their 22.5 meter length and 2200 KW power, they were the largest and most powerful steam locomotives which have ever been built before and during the First World War in Europe.