Essentials of Track Maintenance

As mentioned earlier, a well-maintained track provides the base for a safe and comfortable journey. Therefore, for a track to serve its purpose well, the followingcharacteristics are required of it. (a) The gauge should be correct or within the specified limits (b) There should be no difference in cross levels except …

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Track Maintenance

Railway tracks can be maintained either conventionally by manual labour or by the application of modern methods of track maintenance such as mechanical tamping or measured shovel packing. In India, maintaining tracks has traditionally been a manual activity and the ‘calendar system of maintenance’ has taken deep roots. In this system, a timetable or …

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Modern Welded Railway Track

As mentioned earlier, a rail joint is the weakest link in the railway track. The ill effects of the rail joint are well known, including the fact that a track with joints requires about 30% extra maintenance work as compared to a plain track. The best remedy for the problems caused by rail …

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Recent Developments in Welding Techniques

The welding methods described above have been further improved in the recent past by employing new techniques and equipment. These techniques and equipment are described below in detail. Automatic welding recorder The invention of a welding recorder, for controlling the quality of welding in the flash butt welding method is a recent development. …

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Testing of Thermit Welded Joints

A rail joint should be tested for its strength and hardness before it can be accepted for use on the railways. To this end, the following tests are prescribed on Indian Railways. Reaction test The characteristic reaction of the thermit mixture when it is placed in a standard crucible is scrutinized to …

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Precautions During Thermit Welding

In order to ensure the quality of thermit welded joints, the following precautions should be taken. Follow prescribed procedure Thermit welding of joints should be carried out strictly as per the prescribed norms. The horizontal and vertical alignment of two rail ends require special attention at the joint. In particular, case should …

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CREEP And SHRINKAGE OF CONCRETE

CREEP A phenomenon which affects most materials to some extent is that of creep, or timedependentdeformation under constant load. Creep is particularly important in concrete, and affects both the long-term deflections and loss of prestress force in prestressed concrete members. The basic mechanism of creep in concrete is that of …

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STRENGTH OF CONCRETE

The strength of concrete is primarily affected by the water/cement ratio, that is the ratio of the weights of mixing water and cement used in a mix. The lower the water/cement ratio the higher the strength, and typical relationships between water/cement ratio and compressive cylinder strength at different ages. A …

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Types of Doors

Various types of doors are in use which may be classified on the basis of arrangement of shutters,method of constructions, principles of working operations and materials used. Commonly used doorsare briefly explained below: 1. Battened and Ledged Doors:Battens are 100 mm to 150 mm wide and 20 mm thick woodenboards. …

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ROOF

Roof is the upper most portion of the building which protects the building from rain, wind and sun.Various types of roofs used may be divided broadly into three types:1. Flat roofs2. Pitched roofs3. Shells and folded plates. Flat roofs are used in plains where rainfall is less and climate is …

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