GB1293554A - Improvements in and relating to the stopping and manoeuvring of ships - Google Patents

Abstract

1293554 Stopping and manoeuvring ships by water jets NATIONAL RESEARCH DEVELOPMENT CORP 25 March 1970 [26 March 1969] 15797/69 Heading B7V An assembly for stopping or manoeuvring a ship comprises ducting 14 extending between an inlet opening 12 in the bow 58 and an outlet opening 20 in the bottom 22, valves 11 in the ducting being opened to permit flow through the ducting, which directs the flow downwardly from the ship to produce drag. The ducting includes a vaned diffuser section 16 tapering transversely of the ship, Fig. 2 (not shown), and provided with guide vanes. Guide vanes 30 and 33 are provided at the inlet and bend 32, respectively. Vanes 36 in outlet 20 direct the outflow forwards. Pivotable vanes may be provided in outlet 20 for providing transverse flow for steering, Figs. 3a and 4a (not shown). Alternatively, transverse flow may be produced by jets of water emitted in either transverse direction from a plurality of members in the outlet 20, Figs. 3b and 4b (not shown). A propeller 60 provides water flow for manoeuvring at very slow forward speeds. Boundary layer control in the diffuser section may be by a suction or pumping slot. Flow through the ducting may be increased by providing a downwardly extending flap at the forward edge of the outlet, to create a low pressure zone at the outlet, Fig. 6 (not shown). The inlet and outlet may be provided with doors to prevent drag when the assembly is not in use. In another embodiment, Figs. 5a and 5b (not shown), the ducting is divided into two sections in the diffuser and the two sections are connected to respective transversely-spaced outlets. Flow through each section is controlled by valves for steering.