Traction Overview

In the context of trains , traction can be described as a property of wheels to torque over rails without slipping . It depends on a number of factors, including the weight of a vehicle , number of powered axles, torque , track grade and weather conditions .

Most vehicles are designed to function without loss of traction in dry conditions , but the rails become slippery when it’s raining . In that case, gentle applications are advised when accelerating and braking , especially on grades.

Loss of traction causes wheels to either slip or slide . Apart from the imminent wear , poor judgment can lead to severe collisions and derailments .

Most cabs are equipped with an indicator for traction loss, commonly a blinking warning light and sometimes with a buzzer too.

In most situations, to help increase traction, the driver can use an onboard sander . There are cases where adding a slug to the train can help too.

Vehicles that can carry significant amounts of fuel or cargo onboard, such as steam locomotives , may experience drastic differences in traction depending on their load .

See also: Sander, Wheelslip, Wheelslide, Slug, Weather