A scalable earthing switch that incorporates a torsion spring to effect rapid closure of the switch. The torsion spring is supported coaxially about a rotatable shaft on which contact blades are mounted resulting in compact design. The blade contacts are separated axially along the length of the shaft by one or more spacers. By using difference size spacers the distance between adjacent blade contacts can be changed and, thus, the earthing switch can be easily scaled for different applications. A latching (detent) mechanism is provided for latching the switch in an open position.