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Traction Mechanics

Specific Energy Consumption of High Speed Rail as compared to Semi-HSR

By on October 20, 2013
Specific Energy Consumption of High Speed Rail as compared to Semi-HSR

There is a general belief that the train resistance (resulting high specific energy consumption) of high-speed train is high as compared to normal speed train. The UIC sponsored study proved it otherwise with following arguments explained in the discussion Curve Resistance: High speed Rail routes had to be straighter, a must for the high-speed route, […]

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Traction Mechanics – Numerical Problems

By on May 12, 2013

  Q 1: A train weighing 5000T   starts by a locomotive weighing 125T. The starting resistance of locomotive and train are 6 & 4kg/T respectively. What is the total train resistance at the start? 5000*4+125*6=20750Kg Ans:       =20.75T   Q 2 : A train weighting 1500T is moving on a flat and straight territory at […]

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Braking Effort

By on May 12, 2013
Braking Effort

 Braking effort is the effort required to stop the train within safe braking distance. It has safety consequences. Braking effort is required to counter the kinetic energy of train running at a speed V and can be expressed as .       where D is braking distance, Tr(avg) is average train resistance and Tb is […]

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Wheel Slipping and Sliding

By on May 12, 2013
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. Adhesive weight is defined as the force that can be exerted by a wheel without slipping or sliding. Adhesive weight = Coefficient […]

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Tractive Effort

By on May 12, 2013
Tractive Effort

 Tractive effort is the force required to haul a load. Tractive effort when multiplied with speed at which the train is required to run gives the Horse Power. Importance of Tractive effort lies with its capability to start a train on gradient and run it up to a speed of around 30 kmph whereas that […]

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Train, grade, curve and Acceleration Resistance

By on May 12, 2013

Trains resistance is defined in terms of force required to encounter resistance arising due to vehicle, track, grade, curve, acceleration, wind at different time and place etc. Study of these resistances and its impact in train motion is important to develop strategies for reducing it. It is measured in terms of Kg/tonne. Primarily, train Resistance […]

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Adhesion

By on May 12, 2013
Adhesion

Adhesion is one of the most important term used in Railways parlance signifying the ability of efficient heavy haul and safe braking. Adhesion limits the tractive and braking effort per traction and braking wheel respectively. On Indian Railways,  adhesion limitation has caused more concern of wheel slipping and stalling of trains on gradient section and […]

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Traction Mechanics

By on May 6, 2013
Traction Mechanics

Traction Mechanics is the study of train motion. The mechanics involves conversion of overhead electrical power/diesel/steam power in rail horse power to haul a train encountering acceleration, train, grade, curve resistance and similarly braking. Traction Mechanics involves concept of train resistance tractive effort braking effort adhesion balancing speed for detailing the motion of a train. […]

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