In the thread, Holohan contends that the standard railroad gauge in the U.S.—4 feet, 8.5 inches—derives from the way that rail lines were built in England, where engineers based the width of their railroads on the spacing of road ruts in Imperial Rome, which were in turn designed to accommodate the size of horses’ rear
Why is a 4 foot 8 and a half inch?
Standard gauge is 4 feet, 8-1/2 inches.When George Stephenson designed the Stockton & Darlington Railway in the north of England in 1825, he used a gauge of 4 feet, 8 inches simply because he had been familiar with it on a mine tramway called the Willington Way on the Tyne River below Newcastle.
What is the standard distance between railroad tracks?
4 feet
The US standard railroad gauge is 4 feet, 8.5 inches (Gauge means width between the two rails).
Why are railroad tracks built with gaps?
The gaps left between successive rails on a railway track, the reason is that the rails expand in summer. The gap is provided to allow for this expansion. If no gap is left, the expansion in summer will cause the rails to bend sideways. That will result in train accidents.
Why is the distance between railway tracks?
The distance between the two tracks in these railway gauges is 5 ft 6 in (1676 mm). Any gauge wider than the standard gauge or 1,435 mm is called a broad gauge. Broad gauge railways are also used on ports for cranes etc. This gives better stability and they are even better than the thinner gauges.
How is track separation measured?
By definition the track spacing is given from center to center of a rail track. For an actual construction the distance is measured from the inside of a rail head to the matching one of the other track. As far as both tracks have the same gauge this is the same distance.
Why the gaps are left between the successive slab of flyover?
A gap is left between two sections of bridge because to allow thermal expansion during summer so that it will not damage the bridge.
How much percent railway line is electrified currently?
Total Electrification %: 62.69%
What is the distance between railway sleepers?
(3) Sleeper spacing: Maximum centre to centre sleeper spacing should be 600 mm. The clear distance between two sleepers should not be more than 450 mm. The clear distance between joint sleepers should not be more than 200 mm.
Why are bridges built with gaps?
Expansion joints are basically gaps in the bridge that allow the bridge to expand and contract. Without these gaps, the bridge may fall apart. Bridges are typically made of concrete and/or steel. These components expand with higher temperature and contract at lower temperatures.
Why are gaps left on bridges railways and sidewalks?
Intentional cracks in the sidewalk are a perfect example of how engineers deal with thermal expansion. By filling these gaps with a flexible material, the engineers create what’s known as a “expansion joint,” something that’s meant to help a structure keep its form even with shifting temperatures.
Why do bridges have expansion gaps?
Bridge expansion joints are what allow the concrete to naturally expand and contract without cracking. The rubber expansion joints are placed at the end of a bridge where it meets up with the freeway. These connectors give the concrete just enough space to move and avoid concrete cracks.
Why does the US not have electric trains?
The U.S. government could require that all railways be electrified by a certain date, if there were ever such political motivation. The large investment necessary is an obvious obstacle, and the interest in reducing the nation’s carbon footprint by switching to electric rail is not strong in Congress.
What is the largest electric rail network in the world?
The Swiss rail network
The Swiss rail network is the largest fully electrified network in the world and one of only two to achieve this, the other being Armenia. India and China have the largest electrified railway length with just over 70% of the network.
Where are the longest trains in the world?
The Trans-Siberian Railway (the Moscow-Vladivostok line), spanning a length of 9,289km, is the longest and one of the busiest railway lines in the world.
What type of steel is used in railway tracks?
Modern track typically uses hot-rolled steel with a profile of an asymmetrical rounded I-beam. Unlike some other uses of iron and steel, railway rails are subject to very high stresses and have to be made of very high-quality steel alloy.
What size is a railway sleeper?
Sleeper Sizes
The most common length for railway sleepers is 2.6 metres or 8ft 6″ long. The most common width is 250mm or 10″. And the most common thickness is 125mm & 150mm (5″ & 6″).
What is the minimum spacing between sleepers in broad gauge?
Sleeper Density and Spacing of Sleepers
| Spacing of sleepers | Broad gauge | |
|---|---|---|
| spacing (mm) | ||
| Wooden | Metal | |
| Between joint sleepers (a) | 300 | 380 |
| Between joint sleepers and the first | 610 | 610 |
What will happen if bridges are built without gaps or expansion joints?
Expansion joints prevent build up of resonant frequencies, which dangerously amplify the swaying motion of bridges. Without such joints, bridges are liable to collapse.
What are expansion gaps on roads for?
An expansion joint is designed to absorb safely the expansion and contraction of several construction materials, absorb vibrations, and permit soil movements due to earthquakes or ground settlement. The expansion joints are normally located between sections of bridges, paving slabs, railway tracks, and piping systems.
Are bridges supposed to shake?
De Santos said it’s normal for bridges like this to move a bit. “The bridge will expand and contract based on temperature, the bridge will flex based on the different loads, like 18-wheelers and trash trucks, and the bridge may move vertically and horizontally during an earthquake.
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