“Narrow-gauge railway”的意思、由来-开放百科全书

A narrow-gauge railway (narrow-gauge railroad in the US) is a railway with a track gauge narrower than standard {{Track gauge|1435mm}}. Most narrow-gauge railways are between {{Track gauge|600mm|lk=on}} and {{Track gauge|1067mm|lk=on}}.

Since narrow-gauge railways are usually built with tighter curves, smaller structure gauges, and lighter rails, they can be less costly to build, equip, and operate than standard- or broad-gauge railways (particularly in mountainous or difficult terrain). Lower-cost narrow-gauge railways are often built to serve industries and communities where the traffic potential would not justify the cost of a standard- or broad-gauge line.

Narrow-gauge railways have specialized use in mines and other environments where a small structure gauge necessitates a small loading gauge. They also have more general applications. Non-industrial, narrow-gauge mountain railways are (or were) common in the Rocky Mountains of the United States and the Pacific Cordillera of Canada, Mexico, Switzerland, the former Yugoslavia, Greece, and Costa Rica. In some countries, narrow gauge is the standard; Japan, Indonesia, Taiwan, New Zealand, South Africa, and the Australian states of Queensland, Western Australia and Tasmania have a {{Track gauge|3ft6in|lk=on}} gauge, and Malaysia and Thailand have metre-gauge railways. Narrow-gauge trams, particularly metre-gauge, are common in Europe.

Nomenclature

In general, a narrow-gauge railway is narrower than {{track gauge|1435 mm}}. Because of historical and local circumstances, however, the definition of a narrow-gauge railway varies.

History

Early hand-worked lines

The earliest recorded railway appears in Georgius Agricola's 1556 De re metallica, which shows a mine in Bohemia with a railway of about {{Track gauge|2ft|lk=on}} gauge. During the 16th century, railways were primarily restricted to hand-pushed, narrow-gauge lines in mines throughout Europe. In the 17th century, mine railways were extended to provide transportation above ground. These lines were industrial, connecting mines with nearby transportation points (usually canals or other waterways). These railways were usually built to the same narrow gauge as the mine railways from which they developed.^[1]

Introduction of steam

The world's first steam locomotive, built in 1802 by Richard Trevithick for the Coalbrookdale Company, ran on a {{Track gauge|3ft|lk=on}} plateway. The first commercially successful steam locomotive was Matthew Murray's Salamanca built in 1812 for the {{Track gauge|4ft 1in|lk=on}} Middleton Railway in Leeds. Salamanca was also the first rack-and-pinion locomotive. During the 1820s and 1830s, a number of industrial narrow-gauge railways in the United Kingdom used steam locomotives. In 1842, the first narrow-gauge steam locomotive outside the UK was built for the {{Track gauge|1100mm}}-gauge Antwerp-Ghent Railway in Belgium. The first use of steam locomotives on a public, passenger-carrying narrow-gauge railway was in 1865, when the Ffestiniog Railway introduced passenger service after receiving its first locomotives two years earlier.^[2]

Industrial use

Many narrow-gauge railways were part of industrial enterprises and served primarily as industrial railways, rather than general carriers. Common uses for these industrial narrow-gauge railways included mining, logging, construction, tunnelling, quarrying, and conveying agricultural products. Extensive narrow-gauge networks were constructed in many parts of the world; 19th-century mountain logging operations often used narrow-gauge railways to transport logs from mill to market. Significant sugarcane railways still operate in Cuba, Fiji, Java, the Philippines, and Queensland, and narrow-gauge railway equipment remains in common use for building tunnels.

Internal-combustion locomotives

The first use of an internal combustion engine to power a narrow-gauge locomotive was in 1902. F. C. Blake built a 7hp petrol locomotive for the Richmond Main Sewerage Board sewage plant at Mortlake. This {{TrackGauge|2ft 9in}} gauge locomotive was probably the third petrol-engined locomotive built.^[3]

First World War and later

Extensive narrow-gauge rail systems served the front-line trenches of both sides in World War I.^[4]^[5] They were a short-lived military application, and after the war the surplus equipment created a small boom in European narrow-gauge railway building.

Advantages

Narrow-gauge railways usually cost less to build because they are usually lighter in construction, using smaller cars and locomotives (a smaller loading gauge), smaller bridges and tunnels (a smaller structure gauge), and tighter curves. Narrow gauge is often used in mountainous terrain, where engineering savings can be substantial. It is also used in sparsely populated areas where the potential demand is too low for broad-gauge railways to be economically viable. This is the case in parts of Australia and most of Southern Africa, where poor soils have led to population densities too low for standard gauge to be viable.

For temporary railways which will be removed after short-term use, such as logging, mining or large-scale construction projects (especially in confined spaces, such as the Channel Tunnel), a narrow-gauge railway is substantially cheaper and easier to install and remove. Such railways have almost vanished, however, due to the capabilities of modern trucks.

In many countries, narrow-gauge railways were built as branch lines to feed traffic to standard-gauge lines due to lower construction costs. The choice was often not between a narrow- and standard-gauge railway, but between a narrow-gauge railway and none at all.

{{anchor|Disadvantages|Solutions to disadvantages}}Disadvantages and solutions

Interchangeability

Narrow-gauge railways cannot freely interchange rolling stock (such as freight and passenger cars) with the standard- or broad-gauge railways with which they link, and the transfer of passengers and freight require time-consuming manual labour or substantial capital expenditure. Some bulk commodities, such as coal, ore, and gravel, can be mechanically transshipped, but this is time-consuming, and the equipment required for the transfer is often complex to maintain.

If rail lines with other gauges coexist in a network, in times of peak demand it is difficult to move rolling stock to where it is needed when a break of gauge exists. Sufficient rolling stock must be available to meet a narrow-gauge railway's peak demand (which might be greater in comparison to a single-gauge network), and the surplus equipment generates no cash flow during periods of low demand. In regions where narrow gauge forms a small part of the rail network (like Russia's Sakhalin Railway), extra money is needed to design, produce or import narrow-gauge equipment.

Solutions to interchangeability problems are bogie exchanges, a rollbock system, variable gauge, dual gauge or gauge conversion. European standard-gauge trains normally use buffers and chain couplers, which do not permit tight curves (a main reason for narrow gauge). Narrow-gauge trains normally use other couplers, which makes bogie exchange meaningless. A narrow-gauge-only rail network could also eliminate interchangeability problems.

Growth potential

Another problem commonly faced by narrow-gauge railways is that they lack the space to grow; their cheap construction was engineered only for initial traffic demands. Many narrow-gauge railways were impractical to improve; speeds and loads hauled could not increase, so traffic density was limited. In Japan, a few narrow-gauge lines have been upgraded to standard-gauge mini-shinkansen to allow through service by standard-gauge high-speed trains; due to the alignment and minimum curve radius of those lines, however, the maximum speed of the through service is the same as the original narrow-gauge line. If a narrow-gauge line is built to a higher standard, like Japan's proposed Super Tokkyū, this problem can be minimized.

If narrow-gauge rails are designed with potential growth in mind (or at the same standard as standard-gauge rails), obstacles to future growth would be similar to other rail gauges. For lines constructed to a lower standard, speed can be increased by realigning rail lines to increase the minimum curve radius, reducing the number of intersections or introducing tilting trains.

Successful railways

The heavy-duty {{Track gauge|3ft6in|lk=on}} narrow-gauge railways in Queensland, South Africa, and New Zealand demonstrate that if track is built to a heavy-duty standard, performance almost as good as a standard-gauge line is possible. Two-hundred-car trains operate on the Sishen–Saldanha railway line in South Africa, and high-speed Tilt Trains run in Queensland. Another example of a heavy-duty narrow-gauge line is Brazil's EFVM. {{Track gauge|1000mm}} gauge, it has over-100-pound rail ({{convert|100|lb/yd|kg/m|1|abbr=on|disp=or}}) and a loading gauge almost as large as US non-excess-height lines. The line has a number of {{convert|4000|hp|adj=on}} locomotives and 200-plus-car trains. In South Africa and New Zealand, the loading gauge is similar to the restricted British loading gauge; in New Zealand, some British Rail Mark 2 carriages have been rebuilt with new bogies for use by Tranz Scenic (Wellington-Palmerston North service), Tranz Metro (Wellington-Masterton service), and Transdev Auckland (Auckland suburban services).

Fastest trains

Narrow gauge's reduced stability means that its trains cannot run at speeds as high as on broader gauges. For example, if a curve with standard-gauge rail can allow speed up to {{convert|145|km/h|mph|abbr=on}}, the same curve with narrow-gauge rail can only allow speed up to {{convert|130|km/h|mph|abbr=on}}.^[6]

In Japan and Queensland, recent permanent-way improvements have allowed trains on {{Track gauge|3ft6in}} gauge tracks to exceed {{convert|160|km/h|mph|abbr=on}}. Queensland Rail's Electric Tilt Train, the fastest train in Australia and the fastest {{Track gauge|3ft6in}} gauge train in the world, set a record of {{convert|210|km/h|mph|abbr=on}}.^[7] The speed record for {{Track gauge|3ft6in}} narrow-gauge rail is {{convert|245|km/h|mph|abbr=on}}, set in South Africa in 1978.^[8]^[9]^[10]

A special {{Track gauge|2ft|lk=on}} gauge railcar was built for the Otavi Mining and Railway Company with a design speed of 137 km/h.^[11] Curve radius is also important for high speeds: narrow-gauge railways allow sharper curves, which limits a vehicle's safe speed.

{{anchor|Gauges used}}Gauges

Many narrow gauges, from {{Track gauge|15in}} gauge and {{Track gauge|sg}} gauge, are in present or former use. They fall into several broad categories:

{{anchor|Four foot six inch gauge}}4 ft 6 in gauge

{{anchor|Three foot six inch gauge}}3 ft 6 in gauge

Similar gauges

Metre gauge and Italian metre gauge

As its name implies, metre gauge is a track gauge of {{Track gauge|1000mm}}. It has about {{convert|95000|km|mi|abbr=on}} of track.

According to Italian law, track gauges in Italy were defined from the centre of each rail rather than the inside edges of the rails. This gauge, measured {{Track gauge|950mm}} between the edges of the rails, is known as Italian metre gauge.

3 ft, 900 mm, and Swedish three foot gauge

There were a number of large {{Track gauge|3ft}} railroad systems in North America; notable examples include the Denver & Rio Grande and Rio Grande Southern in Colorado and the South Pacific Coast and West Side Lumber Co of California. {{Track gauge|3ft|disp=1}} was also a common track gauge in South America, Ireland and on the Isle of Man. {{Track gauge|900mm|disp=1}} was a common gauge in Europe. Swedish three-foot-gauge railways ({{Track gauge|891mm|disp=or}}) are unique to that country.

2 ft 9 in gauge

A few railways and tramways were built to {{Track gauge|2ft9in}} gauge, including Nankai Main Line (later converted to {{Track gauge|3ft6in|disp=or}}), Ocean Pier Railway at Atlantic City, Seaton Tramway (converted from {{Track gauge|2ft|disp=1}}) and Waiorongomai Tramway.

{{anchor|800 mm, Two foot six inch, Bosnian, and 750mm gauge}}800 mm, 2 ft 6 in, Bosnian and 750 mm gauge

Gauges between 2 ft and 2 ft 6 in

Gauges such as 2ft 3in (686mm), 2ft 4in (711mm) and 2ft 4.5in (724mm) were used in parts of the UK, particularly for railways in Wales and the borders, with some industrial use in the coal industry. Some sugar cane lines in Cuba were 2ft 3.5in (698.5mm).

{{anchor|Two foot and 600 mm gauges}}2 ft and 600 mm gauges

Minimum gauge

Gauges below {{Track gauge|1ft11.5in}} were rare. Arthur Percival Heywood developed {{Track gauge|15in}} gauge estate railways in Britain and Decauville produced a range of industrial railways running on {{Track gauge|500mm}} and {{Track gauge|400mm}} tracks, most commonly in restricted environments such as underground mine railways, parks and farms, in France. Several {{Track gauge|18in}} gauge railways were built in Britain to serve ammunition depots and other military facilities, particularly during World War I.