FWD - Flat Wheel
A NGRT Flat Wheel Detection (FWD) is a system designed to detect flat wheels on the train cars when crossing the vibration detection unit.
A ﬂat wheel has the potential to cause extensive damage to the rail network, such as broken rails and in worst case scenario a derailment. A ﬂat spot, or ﬂ at wheel is a fault in railroad wheel shape. A ﬂ at spot occurs when a rail vehicle’s wheel set is dragged along the rail after the wheel/axle has stopped rotating. Flat spots are usually caused by use of the emergency brake, or slip and slide conditions that causes wheels to lock up while the train is still moving. Flat spots are more common in the autumn and winter when the rails are slippery. Flat spots can also be caused by faulty brakes or wheel set bearings.