Rail transport

Rail transport
Operations
Stations
Trains
Locomotives
Rolling stock
History
Terminology
Terminology
By country
Disasters
Modelling

Rail transport refers to the land transport of passengers and goods along railways or railroads. A railway (or railroad) track consists of two parallel rail tracks, formerly of iron now of steel, generally mounted upon cross beams (termed " sleepers" ( Commonwealth) or " railroad ties" ( U.S.) ) of timber, concrete or steel. The underlying support maintains the rails at a fixed distance ( gauge) apart. Usually vehicles running on the rails are arranged in a train (a series of individual powered or unpowered vehicles linked together). The cars move with much less friction and the locomotive that pulls the train uses much less energy than is needed to pull wagons. The engineering history focuses on bigger and more powerful locomotives, with an improved track structure to support it, and better brakes and signals, so that longer, faster, heavier and more efficient trains can be operated.

General

Rail transport is an energy efficient means of mechanised land transport. The rail tracks provide very smooth and hard surfaces on which the wheels of the train may roll with a minimum of friction. As an example, a typical carriage can hold up to 125 tons of freight with this and the weight of the car on two four-wheel bogies. Fully loaded, the contact between each wheel and the rail is the space of about one U.S. ten-cent piece. This can save energy compared with other forms of transportation, such as road transport which depends on rubber wheels on pavement. Trains also have a small frontal area in relation to the load they are carrying, which cuts down on air resistance and thus energy usage. In all, under the right circumstances, a train needs 50-70% less energy to transport a given tonnage of freight (or given number of passengers), than does road transport. Furthermore, the rails and sleepers distribute the weight of the train evenly, allowing significantly greater loads per axle/wheel than in road transport, leading to less wear and tear on the right of way.

Rail transport makes highly efficient use of space: a double-tracked rail line can carry more passengers or freight in a given amount of time than a four-laned road.

As a result, rail transport is often the major form of public transport in many countries. In Asia, for example, many millions use trains as regular transport in India, South Korea, Japan, China, and elsewhere.

Commercially, rail transport has had a mixed record. Most rail systems, including urban metro/ subway ( rapid transit) systems, are highly subsidised and have never or rarely been profitable; however, their indirect benefits are often great. For example, despite a well-developed network consisting of four grades of trains and a widespread urban rail network in Seoul and Pusan, Korean National Rail is a nationalized organization that has never come close to having receipts equal costs.

Similarly, passenger rail in all countries is dependent on government subsidies. As a result levels of rail transport have in some times and places been reduced in order to save money.

Conversely, US freight railways have consolidated and become more efficient in their progress toward profitability. The East Japan Railway Company has taken an innovative and creative marketing stance and have achieved profitability as a result.

Like other forms of public transport, many railways are having to make considerable investment in order to meet new requirements for security in the face of recent terrorism incidents, for instance the Madrid train bombings of 11 March 2004. Securing railways is often more difficult than other modes of transport because stations are designed with easy access and high capacity as their primary goals rather than security; because most trains make many stops, rendering any sort of passenger screening difficult; and because securing the tracks as they run through cities and the countryside is impractical.

It is difficult to make a complete and accurate comparison of the economics of various modes of transport as all modes benefit from substantial government, as well as private, spending. For example, public highways, airports and sea ports all typically receive very large capital subsidies.

Operations

A rail transport system consists of several necessary elements, and should be viewed from a system-wide perspective when planning, constructing and maintaining it. Some locomotives may be wonderfully aesthetic constructions, but they will not work unless they are given an appropriate system on which to run. This system includes infrastructure such as tracks, railroad switches or points, signals, classification yards, etc.

Firstly there is the geography onto which the permanent way is built. Next are the requirements of the system – what was it built for? For carrying cargo, commuters, medium or long-distance travellers? Has that requirement changed over time and left the system to adapt?

As a result of this, what is the type of system? Is it light rail or rapid transit, high-speed or industrial rail? To what gauge is it built? In a broader sense, rail transport includes monorail, rubber-tyred metros and maglev, since the cars also run in a guided path. (The term "guideway" describes the non-traditional modes better.)

Trains require a propulsion mechanism: horses, or steam, diesel or electric locomotives. The last of these options, the most energy-efficient, requires electrification of the system. To be electrified, a means of supplying electricity to the train is needed. This can be done with overhead wires or with a third-rail system. The former is the more common method.

Depending on how much traffic they carry, railways can be built with a varying number of tracks. Rail lines that carry little traffic are often built with a single track used by trains in both directions; on rail lines like these, "crossovers", "passing loops" or "passing sidings", which consist of short stretches of double track, are provided along the line to allow trains to pass each other, and travel in opposite directions. Alternatively, there may be longer sections of the line that are double track - effective timetabling can allow train travel up and down a partially double-track line equivalent to travel on full double tracks. Conversely, double tram track is sometimes interlaced at narrow passages (see tram tracks). Single-track lines are cheaper to build, but can handle only a limited amount of traffic and are consequently mainly used on branch lines.

On busier lines two or more tracks are provided, one or more for each direction of travel. On very busy lines as many as eight tracks (four tracks in each direction) are used to handle large amounts of traffic.

With the advent of containerized freight in the 1960s, rail and ship transportation have become an integrated network that moves bulk goods very efficiently with a very low labor cost. An example is that goods from east Asia that are bound for Europe will often be shipped across the Pacific and transferred to trains to cross North America and be transferred back to a ship for the Atlantic crossing.

Major cities often have metro and/or light rail/ tram systems. For a tram on the road the terms streetcar track, tram track or tramway are used, rather than railway or railroad.

Level

Usually railways are at ground level. However, in hilly terrain and mountains, to avoid large slopes, the railway is at some places elevated, on an embankment or bridge / viaduct, and at some places in a cutting ( ditch / trench) or tunnel. The same are also used for non-level crossings. In the case of many crossings, such as in a city, a longer stretch may be elevated or underground.

Safety and railway disasters

Trains can travel at very high speed, are heavy, are unable to deviate from the track and require a great distance to stop. Possibilities for accidents include jumping the track ( derailment), head-on collision with another train coming the opposite way and collision with an automobile at a level crossing (also called a grade crossing). Level crossing collisions are relatively common in the United States where there are several thousand each year killing about 500 people - although the comparable figures in Britain are 30 and 12. For information regarding major accidents, see List of rail accidents.

The most important safety measure is railway signalling. Train whistles warn others of the presence of a train, trackside signals maintain the distances between trains. In Britain, vandalism is thought responsible for about half of rail accidents.

Railroad lines are zoned or divided into blocks guarded by combinations of block signals, operating rules, and automatic-control devices so that at most one train may be in a block at any time . Such traffic control is done in a similar way to air traffic control.

Compared to road travel, railways remain relatively safe. Annual death rates on roads are over 40,000 in the United States & about 3000 in Britain, compared with a thousand passenger fatalities on railways in the United States and under 20 in Britain. (Sources: U.S. Department of Transportation and U.K. Health & Safety Executive). However, a true comparison needs to take account of the number of people using each mode.

History

The Diolkos was a 6-km long railway that transported boats across the Corinth isthmus in Greece in the 6th century BC. Trucks pushed by slaves ran in grooves in a limestone track. The Diolkos ran for over 1300 years, until 900 AD.

The first horse-drawn wagonways appeared in Greece, Malta, and parts of the Roman Empire at least 2000 years ago, using cut-stone track. They began reappearing in Europe from around 1550, usually operating with crude wooden track.

In the late 18th century iron rails began to appear: British civil engineer William Jessop designed edge rails to be used with flanged wheels for use on a scheme in Loughborough, Leicestershire in 1789 and subsequently opened an iron-works to produce more rails. In 1802, Jessop opened the Surrey Iron Railway in south London - arguably the world's first public railway, albeit a horse-drawn one.

The first steam locomotive to operate on rails, built by Richard Trevithick, was operated in 1804 in Wales. It was not financially successful, with Trevithick ending bankrupt. In 1806 a horse-drawn railway was built between Swansea and Mumbles. In 1807 this railway started carrying fare-paying passengers - the first in the world to do so.

In 1811 John Blenkinsop designed the first successful and practical railway locomotive [1].He patented (No 3431), a system of moving coals by a rack railway worked by a steam locomotive, and a line was built connecting the Middleton Colliery to Leeds. The locomotive was built by Matthew Murray of Fenton, Murray and Wood.

It had double-acting cylinders and, unlike the Trevithick pattern, no flywheel. The cylinders drove a geared wheel which engaged under the engine with the rack. This design was quickly superseded following the discovery the railroad tracktion properties by George Stephenson during construction of the Stockton and Darlington Railway.

In 1812 the Middleton Railway which had been built to carry coal from the pits to Leeds became to first railway to successfully use steam locomotives on a commercial basis.

The Stockton and Darlington Railway, ran in northern England in the 1820s. This was soon followed by the Liverpool and Manchester Railway, which proved the viability of rail transport, with George Stephenson's famous Rocket steam locomotive. Railways soon spread throughout Britain and through the world, and became the dominant means of land transport for nearly a century, until the invention of aircraft and automobiles, which prompted a gradual decline in railways.

The first railroad in the United States may have been a gravity railroad in Lewiston, New York in 1764. The Leiper Railroad in Pennsylvania was the first permanent railroad, opened in 1810, and the Granite Railroad in 1826 may have been the first to evolve through continuous operations into a common carrier. The Baltimore and Ohio, opened in 1830, was the first to evolve into a major system.

The use of overhead wires conducting electricity, invented by Granville T. Woods in 1888, amongst several other improvements by Woods, led to the development of electrified railways, the first of which was operated at Coney Island from 1892. Diesel and electric trains and locomotives replaced steam in many countries in the decades after World War II.

Many countries since the 1960s have adopted high-speed railways.

On 24 August 2005 the Qingzang Railway became the highest railway track in the world, when track was laid through the Tanggula Mountain Pass at 5072 meters above sea level. [2]

Terminology

In Britain and other Commonwealth of Nations countries the term railway is used in preference to railroad, while in the United States the reverse is true. However, railroad was used in Britain concurrently with railway until the 1850s when railway became the established term. Furthermore a number of American companies have railway in their names instead of railroad, the BNSF Railway being the most pre-eminent modern example.

In Britain the term railway often refers to the complete organisation of tracks, trains, stations, signalling, timetables and the operating companies that collectively make up a coordinated railway system, while permanent way or p/way refers to the tracks alone.

Subways, metros, elevated lines, trolley lines, and undergrounds are all specialized railways.

Rail transport by country

Of 236 countries and dependencies, 143 have rail transport (including several with very little), of which about 90 have passenger services.