A gas-insulated switchgear, GIS, comprising a disconnector-earthing switch, DES, the DES comprising: a housing, two pistons comprising a disconnector piston and an earthing piston, both pistons arranged in the housing and being each extendable and retractable thereto along a respective axis, the axes of the two pistons (30, 40) being at an angle to each other but parallel to a plane; an actuating mechanism arranged to operate the two pistons (30, 40) to place them in three configurations, namely where both the disconnector piston and earthing piston are in their respective retracted positions, where the disconnector piston is in its extended position and the earthing piston is in its retracted position, and where the earthing piston is in its extended position and the disconnector piston is in its retracted position; wherein the actuating mechanism comprises a crankshaft and two piston rods (23, 24), the two piston rods (23, 24) comprising a first piston rod linking the disconnector piston to the crankshaft and a second piston rod linking the earthing piston to the crankshaft, the crankshaft being arranged to rotate about a crank axis perpendicular to the plane parallel to the axes of the two pistons (30, 40) and which intersects the axes of the two pistons (30, 40), and, whenever the earthing piston or disconnector piston is in its respective retracted position, that piston is flush with the housing in that a front end of that piston (30, 40) is in the same plane as a front end of a cylinder opening (13, 14) provided in the housing from which that piston (30, 40) extends; wherein the crankshaft comprises a first crankpin coupled to the first piston rod and a second crankpin coupled to the second piston rod; and wherein the first crankpin and the second crankpin are in a split-crankpin arrangement. a housing, two pistons comprising a disconnector piston and an earthing piston, both pistons arranged in the housing and being each extendable and retractable thereto along a respective axis, the axes of the two pistons (30, 40) being at an angle to each other but parallel to a plane; an actuating mechanism arranged to operate the two pistons (30, 40) to place them in three configurations, namely where both the disconnector piston and earthing piston are in their respective retracted positions, where the disconnector piston is in its extended position and the earthing piston is in its retracted position, and where the earthing piston is in its extended position and the disconnector piston is in its retracted position; wherein the actuating mechanism comprises a crankshaft and two piston rods (23, 24), the two piston rods (23, 24) comprising a first piston rod linking the disconnector piston to the crankshaft and a second piston rod linking the earthing piston to the crankshaft, the crankshaft being arranged to rotate about a crank axis perpendicular to the plane parallel to the axes of the two pistons (30, 40) and which intersects the axes of the two pistons (30, 40), and, whenever the earthing piston or disconnector piston is in its respective retracted position, that piston is flush with the housing in that a front end of that piston (30, 40) is in the same plane as a front end of a cylinder opening (13, 14) provided in the housing from which that piston (30, 40) extends; wherein the crankshaft comprises a first crankpin coupled to the first piston rod and a second crankpin coupled to the second piston rod; and wherein the first crankpin and the second crankpin are in a split-crankpin arrangement.