What causes locomotive wheel slip?

Causes. The causes of locomotive wheelslip vary, but the predominant factor lies in the power-to-weight ratios. However, if the power of a locomotive vastly exceeds its weight, then an imbalance ensues which causes the violent spinning of the wheels through loss of traction.

How do trains get traction on rails?

Trains get traction because of the immense weight of the locomotives, and the friction generated between the wheel and rail head. Furthermore, in less than ideal weather conditions, sand is sprayed on the rail head to reduce wheel slip.

How does wheel slide protection work?

Speed sensors, the part of the system detect the speed of the wheel & sends signal to the processor unit. The processor unit evaluates the received signal from speed sensor of the vehicle & generates signals enabling the dump valve/antiskid valves to control the brake cylinder pressure in case of any locking/skidding.

What is wheel creep?

Creep forces increase as the relative velocity between wheel and rail increases. This relative velocity, normalised by the rolling velocity, is termed the creepage.

What is wheel slip?

Transmits tyre traction or braking forces, so a relative movement arises between the road and the tyre, i.e. the peripheral speed of the wheel is smaller or greater than the car speed. That difference is called wheel slip. However, the wheel slip is an undesirable effect that impairs driving safety.

How do I stop my wheels slipping?

Sanding is one method of reducing wheel slip or slide. Locomotives and Multiple units have sandboxes which can deliver dry sand to the rails in front of the wheels. This may be initiated automatically when the Wheel Slide Protection system senses loss of adhesion, or the driver can operate it manually.

What is locomotive traction?

A traction motor is an electric motor used for propulsion of a vehicle, such as locomotives, electric or hydrogen vehicles, elevators or electric multiple unit.

How do you stop a slipping wheel?

Do train wheels roll?

If the two wheels rotate the same amount, they would have to roll the same distance. The only way for a flat train wheel to make this turn is for one of the wheels to stop rolling and start sliding. Of course sliding wheels on a train track would sort of defeat the whole reason for using wheels in the first place.

How is wheel slip calculated?

Tire Slip is totally depended on the adhesion between road and tire, and the Normal load, F=mu(N). F here is your braking force. the small amount of wheel slip is always present like 1-5 percent and it changes when you want to transfer more force.

What is slip start?

Slip Start (SS) is used in deep snow, sand, or mud, where it is beneficial to allow the tires to spin in order to gain traction. This is the same as deactivating Vehicle Dynamic Control (VDC) on most ICE.

What is the effect of wheel slip on a train?

With protection system invariable effective, damages on account of wheel slip is very less but may result in stalling of train if the need for tractive effort continuous to more than the adhesive weight. A slipping wheel will generate higher back emf thus less traction current and wheel slipping can be detected by comparing traction current.

What is wheelslip on a locomotive?

Locomotive wheelslip is an event that affects railway motive power usually when starting from stationary, but can also affect an engine in motion.

What is the difference between wheel slipping and wheel sliding?

Wheel Slipping and Sliding. Wheel slipping occurs when tractive effort exceeds adhesive weight whereas sliding occurs when braking effort exceeds adhesive weight. In both the situations, it is the adhesive weight playing the most important role.

What causes a locomotive to lose traction?

Other causes include the contact of oil with the flanges and rims of wheels, which reduces adhesion with the surface of the rails, and a general loss of traction on steep gradients when pulling heavy loads. Most locomotives are fitted with sandboxes, so that sand or Sandite can be dropped on the rails to improve adhesion.