by Lochan Yadav
Coning Of Wheel:
The rim or flanges of the wheels are never made flat but they are in the shape of a cone with a slope of about 1 to 20. This is known as coning of wheels. The coning of wheels is mainly done to maintain the vehicle in the central position with respect to the track. When the vehicle is moving on levelled track then the flanges of wheels have equal circumference. But when the vehicle is moving along a curved path then in this case the outer wheel has to cover a greater distance than that of the inner wheel. Also as the vehicle has a tendency to move sideways towards the outer rail, the circumferences of the flanges of the inner wheel and will help the outer wheel to cover a longer distance than the inner wheel. In these ways, smooth-riding is produced by means of coning of wheels.
Advantages of Coning of Wheels:
Smooth riding - Help vehicle to negotiate curves smoothly
Reduces wear and tear of wheel flanges. Damage is caused because of the friction action of rims with the inner faces of the rail top.
It prevents, to some extent, the slipping of the wheels.
It gives an option of lateral drift of the hinge with its wheels.
Disadvantages of Coming of Wheels:
Pressure on the outer rail is more while on the inner rail it is less. This results in wear of outer rail.
Due to the centrifugal force, the horizontal components tend to turn the rail out and the gauge has a widening tendency.
If no base plate is used under the voids sleepers under the edge of the rail are damaged.
In order to minimize the above mentioned disadvantages, the Tilting of Rails is done.
Tilting of Rails
In order to minimize the disadvantages caused by coning of wheels, the rails are tilted inwards at an angle of 1 in 20. This reduces wear on the rail as well as on the tread of the wheel. Tilting of rails can be achieved by:
Adzing of Sleepers
Use of Canted Base Plate.
Advantages of Tilting Of Rails
The wear at the head of the rail is uniform,
It maintains the gauge properly
It increases the life of sleepers and rails.