How is ballast measured?

In the existing procedure, ballast stack is measured generally with 12-16 measurements of 4 – lengths, 4 – breadths and balance depths. In projects the stacks are generally of large quantity.

Which type of ballast is used in railway tracks?

Broken stone is a widely used ballast in railways. It is obtained by crushing hard stones like granite, hard trap, quartzite etc. In lieu of broken stones, limestone and sandstone can also be used. It is suitable for high-speed railway tracks.

Why ballast is used in railway track?

Track ballast forms the trackbed upon which railroad ties (sleepers) are laid. It is used to bear the load from the railroad ties, to facilitate drainage of water, and also to keep down vegetation that might interfere with the track structure. Ballast also holds the track in place as the trains roll over it.

How does railway ballast work?

Railway ballast is packed beneath the train rails to interlock with the capping layer subgrade and provide a uniform support layer. More ballast is also packed between the sleepers and rail itself to lock them in place to resist the high loads from passing trains (Figure 1).

Is ballast a code?

2.2. 1 Ballast sample should satisfy the following physical properties in accordance with IS:2386 Pt. IV-1963 when tested as per the procedure given in Annexure-I & II.

What is the ballast formation?

Formation: It is the surface on which the ballast is laid. It is also known as the roadbed. 10. Formation-Level: It is the level of the prepared surface on its centre line, including the blanketing material, if any. Shoulder-Ballast: Ballast provided beyond the sleeper edge is called “Shoulder-Ballast”.

Which is the best material to be used as ballast?

Among above materials, broken stone from Igneous rocks like quartzite and granite forms the excellent ballast materials. When these are not available then lime stone and sand stone can also be used as good ballast material.

How many types of ballasts are there?

And there are two types of ballasts in each family: magnetic and electronic. Magnetic ballasts are the older ballast technology. For the fluorescent family, both T12 linear fluorescents and two-pin CFLs use magnetic ballasts.

Which stone is generally used for railway ballast?

Explanation: The following materials for Ballast can be used on the railway track. Among above materials, broken stone from Igneous rocks like quartzite and granite forms the excellent ballast materials. When these are not available then lime stone and sand stone can also be used as good ballast material.

What is needed for a ballast?

Requirements of a Good Ballast

• (a) It should be tough and wear resistant.
• (b) It should be hard so that it does not get crushed under the moving loads.
• (c) It should be generally cubical with sharp edges.
• (d) It should be non-porous and should not absorb water.
• (e) It should resist both attrition and abrasion.

Why railway tracks Cannot be made everywhere?

An insufficient depth of ballast causes overloading of the underlying soil, and in unfavourable conditions overloading the soil causes the track to sink, usually unevenly. Ballast less than 300 mm (11.8 inches) thick can lead to vibrations that damage nearby structures.