A narrow-gauge railway is a railway with a track gauge narrower than standard 1,435 mm. Most narrow-gauge railways are between 600 mm and 1,067 mm.
A light railway is a railway built at lower costs and to lower standards than typical "heavy rail": it uses lighter-weight track, and has more steep gradients and tight curves to reduce civil engineering costs. These lighter standards allow lower costs of operation, at the price of slower operating speeds and lower vehicle capacity.
A dual gauge railway is a track that allows the passage of trains of two different track gauges. It is sometimes called a "mixed gauge" track. A dual gauge track consists of three rails. There will be two vital rails, one for each gauge close together and a third rail, a "common" rail further away. Sometimes, four rails are required using two outer and two inner rails to create the dual gauge. Dual gauge is not to be confused with a "third rail" or "check or guard rails".
Rail transport in Australia is a component of the Australian transport system. It is to a large extent state-based. As of 2018, the Australian rail network consisted of a total of 36,064 kilometres (22,409 mi) of track built to three major track gauges: it had 14,814 kilometres (9,205 mi) of standard gauge ), 15,625 kilometres (9,709 mi) of broad gauge, and 4,225 kilometres (2,625 mi) of narrow gauge lines. Additionally, about 1,400 kilometres (870 mi) of 610 mm / 2 ft gauge lines support the sugar-cane industry.
The Australian state of New South Wales has an extensive network of railways, which were integral to the growth and development of the state. The vast majority of railway lines were government built and operated, but there were also several private railways, some of which operate to this day.
A transporter wagon, in railway terminology, is a wagon (UIC) or railroad car (US) designed to carry other railway equipment. Normally, it is used to transport equipment of a different rail gauge. In most cases, a transporter wagon is a narrower gauge wagon for transporting a wider gauge equipment, allowing freight in a wider gauge wagons to reach destinations on the narrower gauge network without the expense and time of transshipment into a narrower gauge wagons.
Australians generally assumed in the 1850s that railways would be built by the private sector. Private companies built railways in the then colonies of Victoria, opened in 1854, and New South Wales, where the company was taken over by the government before completion in 1855, due to bankruptcy. South Australia's railways were government owned from the beginning, including a horse-drawn line opened in 1854 and a steam-powered line opened in 1856. In Victoria, the private railways were soon found not to be financially viable, and existing rail networks and their expansion was taken over by the colony. Government ownership also enabled railways to be built to promote development, even if not apparently viable in strictly financial terms. The railway systems spread from the colonial capitals, except in cases where geography dictated a choice of an alternate port.
With railways, a break of gauge occurs where a line of one gauge meets a line of a different gauge: specifically a different track gauge. Trains and rolling stock cannot run through without some form of conversion between gauges, leading to passengers having to change trains and freight getting transshipped. A break of gauge adds delays, inconvenience and costs.
The first railway in colonial South Australia was a horse-drawn tramway from the port of Goolwa on the Murray River to an ocean harbour at Port Elliot in 1854. Today the state has 1,600 mm broad gauge suburban railways in Adelaide, a number of country freight lines, as well as key 1,435 mm standard gauge links to other states.
Railways with a track gauge of 3 ft 6 in / 1,067 mm were first constructed as horse-drawn wagonways. From the mid-nineteenth century, the 3 ft 6 in gauge became widespread in the British Empire, was known as the Cape Gauge as it was adopted as the standard gauge for the Cape Government Railways. It was adopted as a standard in Japan and Taiwan.
A level junction is a railway junction that has a track configuration in which merging or crossing railroad lines provide track connections with each other that require trains to cross over in front of opposing traffic at grade.
Rail gauges in Australia display significant variations, which has presented an extremely difficult problem for rail transport on the Australian continent for over 150 years. As of 2014, there are 11,801 kilometres (7,333 mi) of narrow-gauge railways, 17,381 kilometres (10,800 mi) of standard gauge railways and 3,221 kilometres (2,001 mi) of broad gauge railways.
South Australian Railways (SAR) was the statutory corporation through which the Government of South Australia built and operated railways in South Australia from 1854 until March 1978, when its non-urban railways were incorporated into Australian National, and its Adelaide urban lines were transferred to the State Transport Authority.
The rail network in Queensland, Australia, was the first in the world to adopt 1,067 mm narrow gauge for a main line, and now the second largest narrow gauge network in the world, consists of:
The former Victorian Railways, the state railway authority in Victoria, Australia, built a number of experimental 2 ft 6 in narrow-gauge lines around the beginning of the 20th century. Although all were closed by the early 1960s, parts of two have been reopened as heritage railways.
The gauge for the most of the China national railway network is standard gauge. Currently, in the national railway network, only the 1,000 mmmetre gauge Kunming–Hai Phong Railway uses narrow gauge. In addition, there are some industrial lines still using narrow gauge, mostly 2 ft 6 in narrow gauge or 600 mm narrow gauge. As of 2003, 600+ km narrow-gauge railways, 50000+ km standard gauge railways, and 9.4 km broad gauge railways were in use in mainland China.
Gauge conversion is the change of one railway track gauge to another. This may be required if loads are too heavy for the existing track gauge or if rail cars are of a broader gauge than the existing track gauge. Gauge conversion may become less important as time passes due to the development of variable gauge systems, also called Automatic Track Gauge Changeover Systems.
The vast majority of North American railroads are standard gauge. Exceptions include some streetcar, subway and rapid transit systems, mining and tunneling operations, and some narrow-gauge lines particularly in the west, e.g. the isolated White Pass and Yukon Route system, and the former Newfoundland Railway.
Numerous narrow-gauge railway lines were built in [Oceania, most in 3 ft 6 in, 2 ft 6 in and 2 ft track gauge.
