Why are gaps left between rails on a railway track?
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.
What are the defects in rail?
Defects in rails; shatter cracks; detailed fracture; shelling; head-checks; dark-spots; wear. Resistance to structural failure as well as excessive wear is the major criterion involved in the assessment of the structural integrity of rails.
Why do railway tracks expand on hot days?
Because rails are made from steel, they expand as they get hotter, and can start to curve – known as ‘buckling’. Most of the network can operate when track temperatures heat up to 46°C – roughly equivalent to air temperature of around 30°C – but rails have been recorded at temperatures as high as 51°C.
What is used to indicate the level of outer and inner rails on curves?
The level of inner rail of any curve is taken as reference level. Super elevation is provided by raising the outer rail.
What is creep in rail?
Creep of Rail is defined as a longitudional movement of rail with respect to sleeper. Rail have the tendency to gradually move in the direction of dominant traffic. The creep of rail is common to all railway tracks and its value varies from almost nothing in some cases to about 130 mm/ month in creep.
What are the three categories of defects in rails?
Rail defects can be roughly categorized into abrasion (loss of material through friction), deformation, fatigue and machining errors. The maintenance procedure used – grinding or milling – depends not only on the type of defect, but also on its severity.
Why is there no gap between rail sections?
The lack of a gap between rail sections also reduces wear on both the track and the wheels. However, because the weld essentially produces one very long track, the individual sections have no room to expand as they get warm on hot days. What prevents the track from warping beyond usability?
Why are there always Stones alongside railway tracks?
Have you ever given any thought as to why there are almost always stones alongside a railway track? To start with, the stones that you see lying close to the railway tracks are collectively called track ballast. It basically forms the trackbed on which the railway sleepers are kept.
What are the factors that affect a railroad track?
One of these factors is the correct use of rail joints when fastening multiple lengths of rail together with a fishplate. Another important factor is the the tension in the rail. Temperature can have dramatic effects on railroad tracks when the metal in the rail expands or contracts, having the potential to cause the track to buckle or separate.
Why do steel railways not rust and fall apart?
The rail company also grind the track to remove surface imperfections caused by the trains braking, if these imperfections were allowed to worsen and deepen, the high impact force of the train hitting them at high speed could cause the rail to fracture. Coating rails.