A combined sub-aqueous rock-cutter and dredge

180,768. Lobnitz, Sir F. March 5, 1921. Drawings to Specification. Scoop-arm machines; grab machines; vertically-driven rock-breakers. - A vessel carrying dredging apparatus of the scoop-arm or grabtype is provided with rock-cutting means such as described in Specification 8578/06 which is operated from the boom or jib of the dredge and operates within a guide suspended from the boom or jib. The dredge may be dismounted during operation of the cutter and vice versa or each may remain in position while the other is operated; both may be operated from the same winch and the guide may be adjusted by an auxiliary winch or by temporary attachment to the cutter. The guide may comprise a metal tube lined with wood.