Abstract: A method of producing a gas turbine blade having an abrasive tip comprising producing a binding coat on the tip of the blade body by electrodeposition, the binding coat comprising MCrAlY where M is one or more of iron, nickel and cobalt, anchoring to the binding coat coarse particles of an abrasive material by composite electrodeposition of the particles and an anchoring coat from a bath of plating solution having the abrasive particles suspended therein, and then plating an infill around the abrasive particles. The anchoring coat may be of cobalt or nickel or MCrAlY as above defined and preferably has a thickness less than 30 .mu.m. The infill material may also be MCrAlY as above defined. Preferably, deposition of the infill is accompanied by vibration of the blade in a direction which is substantially vertical and substantially along the axis of the blade.

Abstract: A process for the production by electrolytic or electroless deposition on a workpiece of a composite coating comprising a metal matrix containing particles is particularly suitable for workpieces of complex geometry or having abrupt changes of shape or sharp edges such as gas turbine blades. The process in which the particles are codeposited with the metal from a solution in which the particles are insoluble comprises inducing circulation generally upwards in one zone and generally downwards in a second zone, locating the workpiece in the second zone and rotating the workpiece about an axis having a horizontal component, the rotational cycle including periods of higher angular velocity and periods of lower angular velocity, preferably a stop/go cycle. Preferably, the workpiece is also rotated about a second axis which is non-parallel with and preferably perpendicular to the first.

Abstract: A marine unit has an elongate payload-containing body, a plurality of legs each connected by a pivot at its inner end to the lower end of the body, and an actuator in the body for deploying the legs to cause the body to stand upright on the sea bed. The actuator is a double-acting constant displacement piston and cylinder arrangement connected to each of the legs by a link. The link is connected to the piston by a second pivot and to the leg by a third pivot, the geometry of the three pivots being such that the linkage is self-locking and reverse loads on the leg are not transferred to the actuator.

Abstract: A dual gas pressure vessel is divided into a first chamber 22 and a second chamber 24 by collapsible bellows 16. As the gas in the first chamber is dishcarged through an exhaust 29 the bellows collapse until a plate 20 is pierced by a probe 32, following which the gas in the second chamber 24 is vented. A support 26 for the plate 20 ensures that, during charging of the vessel, the first and second chambers are well defined in volume.

Abstract: A method of producing an overlay coating on a substrate such as a turbine blade which comprises: (1) plating a protection layer comprising a metal matrix M.sub.1 containing particles of CrAlM.sub.2, (2) plating an anchoring layer comprising a metal layer containing larger particles, and (3) spray coating a thermal barrier of a refractory material.

Abstract: A dual gas pressure vessel assembly comprising a pressure vessel shell, a piston dividing the interior of the shell into a first chamber and a second chamber, an exhaust passage leading from a portion of said first chamber spaced from the piston, a stop limiting movement of the piston towards the exhaust passage, and a burster disc in the piston. The piston carries frangible coupling means rigidly coupling the piston to the shell. In use the two chambers are respectively filled with the two gases required. When the exhaust passage is opened the first gas will be discharged from the first chamber, the piston will move against the stop and, when substantially all the first gas has been discharged, the burster disc will fracture, connecting the second chamber to the exhaust passage.

Abstract: A marine unit for location on the sea bed has a cylindrical body and legs which are connected to the body by a pivot adjacent one end of the body. Each leg has a toothed member which engages a common worm driven by a motor. The legs are connected by webs of net. The body and nets nest within the legs for storage, the legs are partly opened for the descent, and are opened fully when the unit reaches the sea bottom to support the unit with its axis approximately vertical.