Broad gauge
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- This article is about a rail gauge for real-life railroads. For Lionel's toy train gauge, see Wide Gauge.
Image:GWR broad gauge locomotives.jpg Image:Farranfore train station.jpg Broad gauge railways use a rail gauge (distance between the rails) greater than the standard gauge of 4'8½".
Contents |
Overview
| Gauge | Names and usage | |
|---|---|---|
| Imperial | Metric | |
| 4'-8½" | 1435 mm | Standard gauge |
| 4'-10" | 1473 mm | Ohio gauge |
| 4'-10 7/8" | 1495 mm | Toronto subway track gauge as well as Toronto streetcar track gauge |
| 1520 mm | Russian gauge | |
| 5' | 1524 mm | Finland, most U.S. southern states before the American Civil War |
| 5'-2¼" | 1581 mm | Pennsylvania Trolley gauge, see Southeastern Pennsylvania Transportation Authority subway cars and Southeastern Pennsylvania Transportation Authority |
| 5'-2 1/2" | 1588 mm | Pennsylvania Trolley gauge, see Southeastern Pennsylvania Transportation Authority subway cars and Southeastern Pennsylvania Transportation Authority |
| 5'-3" | 1600 mm | Irish broad gauge, Victorian broad gauge |
| 5'-5½" | 1668 mm | Iberic gauge, used in Portugal and Spain (Renfe) |
| 5'-6" | 1676 mm | India, U.S. (BART), Canada (Grand Trunk Railway, St. Lawrence and Atlantic Railroad and the Champlain and St. Lawrence Railroad until 1873) The Grand Trunk Railway of Canada collections |
| 5ft 8 7/8" | 1750 mm | France, Line originally from Paris to Limours via Saint-Rémy-lès-Chevreuse. From ? till 1891 when it was converted to standard gauge. |
| 6'-4 5/8" | 1945 mm | Netherlands, Dutch broad gauge, 1839-1866 |
| 7'-0¼" | 2140 mm | Great Western broad gauge The "gauge war" |
For a more complete list see: List of broad rail gauges by gauge and country
Details
In Britain the Great Western Railway designed by Isambard Kingdom Brunel pioneered broad gauge from 1838 with a gauge of 7 ft 0¼ in (2140 mm), and retained this gauge until 1892.
While Parliament initially supported the broad gauge, it was eventually rejected by the Gauge Commission in favour of all railways being built to Standard Gauge for compatibility. Parliament was more concerned at this time about making profits rather than improving railway conditions. Broad gauge lines were gradually converted to dual gauge or standard gauge from 1864, and finally the last of Brunel's broad gauge was converted in 1892.
Many countries have broad gauge railways. Ireland (see History of rail transport in Ireland) and some parts of Australia have a gauge of 5 ft 3 in (1600 mm). Russia and the other former Soviet Republics use a 1520 mm (originally 5 ft (1524 mm)) gauge while Finland continues to use the 5 ft (1524 mm) gauge inherited from Imperial Russia (the two standards are close enough to allow full interoperability between Finland and Russia).
In 1839, on the continent, The Netherlands started its railway system with two broad gauge railways. The chosen gauge was 1945 mm after a visit of engineers in England. This was applied between 1839–1866 by the Holland Iron Railway Co. (HSM) for their Amsterdam-The Hague-Rotterdam line and between 1842–1855, firstly by the Dutch state, but soon by the Dutch Rhenish Railway Co. (NRS) for their Amsterdam-Utrecht-Arnhem line. But the neighboring countries Prussia and Belgium used already standard gauge so the two companies had to regauge their first lines. In 1855, NRS regauged her line and shortly after connected to the Prussian raiways. The HSM follows in 1866. There are replicas left of one broad gauge 2-2-2 locomotive (The Arend) and three carriages, all in the Dutch Railway Museum in Utrecht. These replicas were build for the 100-year anniversity of the Dutch Railways in 1938–39.
The Baltic States have received funding from the European Union for rebuilding their railways to the standard gauge. Portugal and the Spanish Renfe system use a gauge of 5 ft 5½ in (1668 mm). In India a gauge of 5 ft 6 in (1676 mm) is widespread. This is also used by the Bay Area Rapid Transit (BART) system of the San Francisco Bay Area. In Toronto, Canada the TTC subways and streetcars use a unique gauge of 4 feet 10 7/8 inches (1495 mm), an "overgauge" originally intended to allow standard gauge horse-drawn wagons to run inside the rails while the streetcars ran on top of them.
While Russia chose broad gauge to make railborne invasion by its enemies that much more difficult, most non-standard broad gauges get in the way of interoperability of railway networks. On the GWR, the 7 ft ¼ in (2140 mm) gauge was supposed to allow for high speed, but the company had difficulty with locomotive design in the early years (which threw away much of their advantage), and rapid advances in permanent way and suspension technology saw standard gauge speeds approach broad gauge speeds within a decade or two in any case. On the 5 ft 3 in (1600 mm) and 5 ft 6 in (1676 mm) gauges, the extra width allowed for bigger inside cylinders and greater power, a problem solvable by outside cylinders and higher steam pressure on standard gauge. On BART, the wider gauge is supposed to prevent lightweight trains from being blown over by the wind.
Railways first appeared in India during the British Raj. There were four competing gauges — a 2' narrow gauge, a 2'5" narrow gauge, metre gauge, and a 5' 6" broad gauge. The broad gauge was thought necessary to keep trains stable in the face of strong monsoon winds.
Eventually, the broad gauge came to be the most prevalent gauge across the Indian subcontinent, reaching right across from Iran to Burma and Kashmir to Tamil Nadu. After Independence, the Indian Railways adopted 5' 6" as the standard Indian Gauge, and began Project Unigauge to convert metre gauge and narrow gauge to broad gauge. Even the newest rail projects in India, such as the Konkan Railway and the Delhi Metro use broad gauge. There was a move to use standard gauge for the Delhi Metro, but it was ordered to use broad gauge to maintain compatibility with the rest of the rail network in India.
Selection of Russian wide gauge
Although it is a popular myth that Russian gauge was selected wider to prevent railroad invasion, this is not true. Russian gauge of 5 ft was approved as the new standard on September 12 1842, while it wasn't until August 12 1846 before British standard was approved. The selection process was done chiefly by Mel'nikov. Probably, a combination of the following arguments was used:
- Easier construction of locomotives
- Better stability
- Wide gauge was seen as a new standard that was emerging in the United States
- Since the gauge was wider than standard road track it was easier to use horse carriages for railroad construction and maintenance.
George Washington Whistler was invited as a foreign expert to assist in railroad construction. He was a proponent of a wider gauge and his efforts helped in lobbying the new standard. It is quite likely that an "invasion" argument (alleging that it is easier to adapt trains to narrow gauge than to wide gauge) was used in lobbying the project since military was closely supervising the construction; however, it is highly unlikely that such an argument was made by Mel'nikov during the actual selection process. It is worth noting that Nazi Germany suffered such problems with their supply lines during World War II as a result of the break-of-gauge.
Although broad gauge was and is quite rare on lighter railways and street tramways, many Russian tramways were and are also built to broad gauge. The former Soviet Union is today the largest operator of first generation tramways in the world, and has been for many years. The modern world's largest tramway network, in Saint Petersburg, Russia, is entirely broad gauge, with some of the world's widest trams, and indeed the widest in Europe (European trams are generally narrower than European busses and trains and also tramcars elsewhere such as America and Australia).
Overcoming a break of gauge
Where trains encounter a different gauge (a break-of-gauge), such as at the Spanish-French border or the Russian-Chinese one, the traditional solution has always been transshipment — transferring passengers and freight to cars on the other system. This is obviously far from optimal, and a number of more efficient schemes have been devised. One common one is to build cars to the smaller of the two systems' loading gauges with bogies that are easily removed and replaced, with switching of the bogies at an interchange location on the border. This takes a few minutes per car, but is quicker than transshipment. A more modern and sophisticated method is to have multigauge bogies whose wheels can be moved inward and outward. Normally they are locked in place, but special equipment at the border unlocks the wheels and pushes them inward or outward to the new gauge, relocking the wheels when done. This can be done as the train moves slowly over special equipment.
In some cases, breaks of gauge are avoided by installing dual gauge track, either permanently or as part of a changeover process to a single gauge. In other cases (in Spain) variable gauge axles are used.
Broader gauges
Some applications for railways require broader gauges, including:
These applications might use double track of the country's usual gauge to provide the necessary stability and axle load.
See also
External links
fr:Voie large ko:광궤 nl:Breedspoor ja:広軌 pl:Kolej szerokotorowa sk:Širokorozchodná železnica sv:Bredspår