Everything about The Standard Gauge totally explained
The
standard gauge (also named the
Stephenson gauge after
George Stephenson) is a widely-used
rail gauge. Approximately 60% of the world's existing railway lines are built to this gauge (see
the list of countries that use the standard gauge). The distance between the inside edges of the rails of standard gauge track is .
History
As
railways developed and expanded one of the key issues to be decided was that of the
rail gauge (the distance, or
width, between the inner sides of the rails) that should be used. The eventual result was the adoption throughout a large part of the world of a "standard gauge" of, allowing inter-connectivity and the inter-operability of
trains.
In
England some early lines in colliery areas in the north east of the country were built to a gauge of ; and in
Scotland some early lines were (
Scotch gauge). By 1846, in both countries, these lines were widened to standard gauge. Parts of the
United States rail system, mainly in the northeast, adopted the same gauge because some early trains were purchased from Britain. However, until well into the second half of the
19th century Britain and the USA had several different track gauges. The American gauges slowly converged as the advantages of equipment interchange became more and more apparent; the destruction of much of the South's
broad gauge system in the
American Civil War hastened this trend.
Origins
A popular legend traces the origin of the gauge even further back than the coalfields of northern England, pointing to the evidence of rutted roads marked by
chariot wheels dating from the
Roman Empire. This legend has been debunked. The historical tendency to place the wheels of horse-drawn vehicles approximately apart probably derives from the width needed to fit a
carthorse in between the shafts . In addition, while road-traveling vehicles are typically measured from the outermost portions of the wheel rims (and there's some
evidence that the first railroads were measured in this way as well), it became apparent that for vehicles traveling on rails, it was better to have the wheel
flanges located
inside the rails, and thus the distance measured on the inside of the wheels (and, by extension, the inside faces of the
rail heads) was the important one.
There was no standard gauge for horse railways, but there were rough groupings: in the north of England none were less than 4ft. Wylam collery's system, built before 1763, was 5ft 0in; as was
John Blenkinsop's
Middleton Railway, the old 4ft plateway was relaid to 5ft so that Blenkinsop's engine could be used.
The beginnings of the 4ft 8½in gauge
George Stephenson used the gauge (with an extra half-inch of free movement to reduce binding on curves the
Eastern Counties Railway, authorised on
4 July 1836, was 5ft 0in;
London and Blackwall Railway, authorised on
28 July 1836, was 5ft 0in; the
London and Brighton Railway, authorised on
15 July 1837, was 4ft 9in; the
Manchester and Birmingham Railway, authorised on
30 June 1837, was 4ft 9in; the
Manchester and Leeds Railway, authorised on
4 July 1836, was 4ft 9in the
Northern and Eastern Railway, authorised on
4 July 1836, was 5ft 0in. The 4ft 9in railways were intended to take gauge
vehicles and allow a running tolerance.
The influence of the Stephensons appears to be the main reason that the gauge became the standard, and its usage became more widespread than any other gauge. .
The Royal Commission
In the
United Kingdom of Great Britain and Ireland, a
Royal Commission in 1845 reported in favour of a standard gauge. In
Great Britain, Stephenson's gauge was chosen as the
standard gauge on the grounds that lines built to this gauge were eight times longer than that of the rival gauge, adopted principally by the Great Western Railway. The subsequent
Gauge Act of 1846
ruled that new passenger-carrying railways in
Great Britain should be built to a standard gauge of ; and those in
Ireland to a standard gauge . It allowed the broad gauge companies in Great Britain to continue repairing their tracks and expanding their networks within the
Limits of Deviation and the exceptions defined in the Act. After an intervening period of
mixed-gauge operation (tracks were laid with three running-rails), the Great Western Railway finally converted its entire network to standard gauge in 1892.
Ideal gauge
Subsequently, engineers have shown that a
narrow gauge is less than ideal: despite usually offering cheaper construction, a smaller gauge restricts speeds due to a reduced load stability. Broader gauges are theoretically more stable at speed and allow larger, wider, heavier loads. According to
Isambard Kingdom Brunel's studies the optimum gauge for a rail system (and the one he originally used on his
Great Western Railway) is 7 ft (2100 mm).
There has been much controversy about what constitutes the "ideal gauge". From a design point of view, a train can travel faster around a given radius of track if the gauge is wider, as the
centre of gravity of the train is further displaced from the wheels, which in turn lowers the angle between the wheel's lower contact surface to the centre of gravity, and horizontal. Given that one can tailor either the track radius for train speed, or the train speed for track radius, gauge in some cases may not be as important as interoperability.
There are many examples of high speed and high mass applications on narrow gauges throughout the world, suggesting that gauge is less important than the original supporters of either
broad gauge or narrower gauges held it to be:
- The heaviest trains in the world run on standard gauge track in Australia, North America and Mauritania. Gauge isn't the limiting factor in running heavier trains.
- The fastest conventional trains in the world also run on standard gauge in Japan and Europe, where speeds over 300 km/h are attained.
- Very heavy trains run on the narrow gauge of in Queensland (Australia) and South Africa, on track as strong as heavy standard gauge track. This narrow gauge doesn't seem to materially affect the weight of trains that can be run on it.
- Fairly fast trains (160 km/h) can run on track, as can be seen in Japan and Queensland.
- It is possible to build a light standard gauge line about as cheaply as a narrow gauge line.
- It is possible to build a narrow gauge line to as heavy-duty a standard as a standard gauge line.
- Loading gauge, structure gauge, axle load, compatibility of couplings, continuous brakes, electrification systems, railway signal systems, radio systems and rules and regulations are also important.
With the benefit of hindsight, little was gained by building railway systems too narrow (down to about ) or too broad (up to about 7 ft (2100 mm)) gauges, and this was at the cost of limited interoperability. For an example of the difficulties of interoperability see the
ramsey car transfer apparatus and the
variable gauge axles used to transfer
cars between different gauges of track.
Only in gauges of less than can a railway be built significantly more cheaply than is possible with standard gauge, and only then in mountainous terrain, or where a low capacity line is required, or with industrial railways where through running isn't required.
It can be argued therefore, that the original uniform gauge adopted by Stephenson in
1830 can serve most of the tasks performed by gauges from 3 to 7 ft (900 to 2100 mm), albeit with a narrow gauge of about for cane tramways, underground mine, mountain, construction, temporary and military railways, plus children's railways.
As the advantages of interchange of equipment between lines became clear, so did standardization of gauge become attractive. Where these advantages are not compelling, use of non-standard gauges continue today.
Sharper curves
Narrow gauge rolling stock tends to be smaller in all directions, so that they can cope with sharper curves. Broad and standard gauge rolling stock may have problems with the same sharp curves because:
wheel base of carriages and wheel base of bogies is too long.
Couplers can't cope with very sharp curves, especially the British style of buffers, hooks and chains.
Brake hoses can't cope or disconnect with very sharp curves.
One might also add that if a too heavy train is pulled around a sharp curve, intermediate wagons may be pulled off the rails and cause a derailment.
For example, the sharpest curve on the 3' 6" gauge Queensland Railways is 200 feet, while the sharpest curve on the 4' 8½" New South Wales Railways is 330 feet.
Experience on the narrow gauge Toronto and Nipissing Railway suggests that 4- and 6-wheel wagons should be avoided and bogie wagons substituted.
Wind
Wind can and does blow trains over on occasion, and the wider the gauge the better. However, this problem is rare, and with weather forecasts and warning devices, precautions can be taken. Monsoon winds were a factor in the choice of Broad Gauge in India, and for the lightweight BART trains in San Francisco. A train was famously blown over on a narrow gauge railway in Ireland. A double stack container train on the standard gauge railway was suspected of having had a few cars blown over during a storm near Tarcoola. The second Tay Bridge is fitted with a device to warn of excessive wind speed.
Piggyback operation
One method of achieving interoperability between rolling stock of different gauges, is to piggyback stock of one gauge on special transporter wagons. This enables rolling stock to reach workshops and other lines of the same gauge to which they're not otherwise connected. Piggyback operation by the trainload occurred as a temporary measure between Port Augusta and Marree during gauge conversion works in the 1950s, to bypass steep gradients in the Flinders Ranges.
Narrow gauge railways were favoured in the underground slate quarries of North Wales, as tunnels could be smaller. The Padarn Railway operated transporter wagons on their gauge railway, each carrying four slate trams. When the Great Western Railway acquired one of the narrow gauge lines in Blaenau Ffestiniog, they used a similar type of transporter wagon in order to use the quarries' existing slate wagons.
Transporter wagons are most commonly used to transport narrow gauge stock over standard gauge lines. More rarely, standard gauge vehicles are carried over narrow gauge tracks using adaptor vehicles; examples include the Rollbocke transporter wagon arrangements in Germany, Austria and the Czech Republic and the milk transporter wagons of the Leek and Manifold Valley Light Railway in England.
Break of gauge
When a railway line of one gauge meets another railway line of a different gauge, there's a break of gauge. A break of gauge adds cost and inconvenience to traffic that must pass from one system to another.
An example of this is on the Transmanchurian Railway, where Russia and Mongolia use broad gauge while China uses the standard gauge. At the border, each carriage has to be lifted in turn to have its bogies changed. The whole operation, combined with passport and customs control, can take several hours.
Other examples include any crossing into or out of the former Soviet Union: Ukraine/Slovakia border on the Bratislava-L'viv train, and from the Romania/Moldova border on the Chisinau-Bucharest train.
This can be avoided however by implementing a system similar to that used in Australia, where lines between states using different gauges are built as dual gauge. Thus the lines have 3 rails, one set of two forming a standard gauge line, with the third rail either inside or outside the standard set forming rails at either narrow or broad gauge. As a result, trains built to either gauge can use the line.
Standard gauge in model railways
model railroading, standard gauge was originally an effort by Lionel Corporation to corner the U.S. market in the early years of the 20th century. Lionel standardized its offerings on three-rail track with a gauge of 2 1/8 in (54 mm) between the outer rails, making it incompatible with Gauge 1 offerings from European manufacturers. Lionel then registered a trademark on Standard Gauge. Other American companies followed Lionel's lead, standardizing on Lionel's new standard but calling it Wide gauge in order to avoid infringing on Lionel's trademark.
Standard gauge fell out of favour in the 1930s because of its high cost, and Lionel discontinued its Standard gauge offerings in 1940.
Although scale modeling wasn't of primary concern, standard gauge's scale is generally accepted at 1:26.59, making it somewhat smaller than G scale.
More recently, standard gauge has come to mean scale modelling in which the track is accurately scaled to real-world standard gauge. This is opposed to narrow gauge modeling, which models real-world narrow gauge, or off-scale modeling, where track isn't true to scale, such as in O gauge and OO gauge.
Further Information
Get more info on 'Standard Gauge'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://standard_gauge.totallyexplained.com">Standard gauge Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |
