(19)

(11)

EP 0 163 682 A1

(12)

(43) Date of publication: 11.12.1985 Bulletin 1985/50 (21) Application number: 84904144.0 (22) Date of filing: 08.11.1984

(51) International Patent Classification (IPC):  E01C 11/ 24( . ) E01H 1/ 10( . ) E01C 23/ 12( . ) (86) International application number: PCT/GB1984/000384 (87) International publication number: WO 1985/002211 (23.05.1985 Gazette 1985/12)

(84) Designated Contracting States: DE FR GB (30) Priority: 08.11.1983 GB 19830029786 (71) Applicant: AQUA-DYNE EUROPE LTD Aberdeen AB2 OGL (GB)	(72) Inventors: FORREST, John Milltimber Aberdeen AB1 0HN (GB) McARTHUR, Alan Bridge of Don Aberdeen AB2 8BZ (GB) JACKSON, Russell Kincardineshire AB3 2HP (GB) (74) Representative: Gray, Robin Oliver  BARON & WARREN 18 South End Kensington London W8 5BU London W8 5BU (GB)