GB1351696A - Device for cutting underwater cables - Google Patents

Abstract

1351696 Shearing RHEINMETALL GmbH 16 Sept 1971 [13 Nov 1970] 43137/71 Heading B3W A cutting device for shearing steel ropes, chains, &c. underwater comprises a cutting charge 2 mounted in a carrier 1, an arm 9 pivotable about a shaft 24 to an open position, shown in broken line in Fig. 2, and means such as a wire 12 restraining the arm from pivoting to the open position, the arm in the open position being disposed to co-operate with the cable to cause detonation of the cutting charge 2. The arm 9, urged by a spring 11 to the open position, is of angle section and mounted within the arm is a rocker 23 also pivoted about shaft 24. A detonation pin 25 projects from one end of the rocker and a spring 26 urges the other end into engagement with a push rod 22. The push rod 22 is located in a socket in the arm 9 which communicates with a piston chamber 19 which has an inlet slot 20 and an outlet bore 21 to ambient water. A spring-urged piston-rod 17 extending into the chamber 19 carries a collar 16 which normally engages the underside of a ring 15 integral with a plate 13. The plate 13 is pivoted to the arm 9 at 14 and connected to the arm by a shear pin 9a. A cable encountering the device, which has a stabilizer 3 to which a tow rope 5 is connected, severs the wire 12 allowing the spring 11 to move the arm 9 to the open position. The cable then presses the plate 13 shearing the pin 9a so that the plate pivots, to a position in which the collar 16 can pass through ring 15. The piston-rod through the water column 28 in chamber 19 forces the push rod 22 against rocker 23 which pivots, causing the pin 25 to puncture a detonator 7. The metal casing of the charge acts as a shear blade, a ceramic plate 6 screening the tow rope from the blast. The retaining wire 12 may be removed by hand before the device is put in the water.