A surface conditioning device for railway track rails and/or railway vehicle wheels includes a DC power supply, a supply of gas, a plasma delivery head connected to receive DC power from the power supply and gas from the gas supply, and an igniter for igniting the gas in the plasma delivery head. In use, plasma is generated within the delivery head by ignition of the gas in the delivery head. Plasma with gas is blown from the delivery head onto a railway track rail and/or railway vehicle wheel, thereby conditioning the rail and/or wheel.