Abstract: Apparatus for dislodging an accretion of a substance from the vicinity of a vessel, includes apparatus for generating gas-borne shock waves in the vicinity of a vessel, thereby to expose a substance accrued on a surface thereof to separation forces causing at least partial separation of the substance from the surface, so as to facilitate removal of the at least partially separated substance therefrom; and support apparatus for supporting the apparatus for generating shock waves in a selected association relative to the vessel.

Abstract: Apparatus for dislodging an accretion of a substance from the vicinity of a vessel, includes apparatus for generating gas-borne shock waves in the vicinity of a vessel, thereby to expose a substance accrued on a surface thereof to separation forces causing at least partial separation of the substance from the surface, so as to facilitate removal of the at least partially separated substance therefrom; and support apparatus for supporting the apparatus for generating shock waves in a selected association relative to the vessel.

Abstract: A self-firing and self-propelling gas impulse device which includes a housing having a longitudinal axis, a gas inlet port, and one or more gas discharge ports; an inlet chamber, arranged for gas communication with a source of compressed gas via the inlet port and operative to receive compressed gas therefrom; a pressurization chamber arranged for gas communication with the inlet chamber thereby to facilitate a build-up of pressurized gas therein, and arranged for selectable gas communication with the one or more discharge ports; and a piston unit arranged along the longitudinal axis of the housing between the inlet chamber and the pressurization chamber.