Vibration damping

A vibration damper for installation between a first blade of a gas turbine engine and a second blade of a gas turbine engine, the second blade being circumferentially adjacent to the first blade, the first blade having associated with it a first, planar face, the second blade having associated with it a second, planar face, the first face and the second face being radially convergent, the damper having associated with it a first, planar friction surface for contacting the first face and a second, planar friction surface for contacting the second face, the first friction surface and the second friction surface being radially convergent, the closest-spaced ends of the first friction surface and the second friction surface being spaced apart by a distance at least as great as the maximum circumferential gap between the radially outer ends of the first face and the second face, the angle subtended by the first friction surface and the second friction surface being smaller than the angle subtended by the first face and the second face;

• wherein the mass of the damper is disposed such that the centre of mass of said damper lies in a plane bisecting the angle subtended by said first friction surface and said second friction surface.