Abstract: Disclosed is a tool for applying torque to an object, the tool comprising: a frame for clamping to the object to which torque is to be applied, the frame comprising a pair of jaws with an adjustable separation therebetween, and an adjuster mechanism to adjust the separation between the jaws; at least one thruster disposed on opposite sides of an intended axis of rotation of the frame, respective thrusters providing thrust in opposite directions, so as to cooperate and generate torque on the frame; characterised in that a displaceable mass is provided within a barrel extending from at least one of said thrusters, which mass is displaced by the thruster upon actuation, so as to increase the recoil, and hence the torque, experienced by the frame upon actuation of the thruster.

Abstract: A housing (1; 100, 104, 102) of a cartridge for a device for firing a projectile has separate first and second chambers (10, 12; 106, 114), each of which contains a respective charge (34, 36; 108, 110, 116, 120) of propellant material. Gas produced by the detonation of one of the charges exits the first chamber to propel the projectile, whilst gas from the detonation of the second charge exist rearwardly from the device so as to counteract recoil. A one way valve may also be provided to help to achieve a high pressure difference between the chambers, where the cartridge has a common igniter assembly.