(19)

(11)

EP 1 056 906 A1

(12)

(43) Date of publication: 06.12.2000 Bulletin 2000/49 (21) Application number: 99903544.7 (22) Date of filing: 17.02.1999

(51) International Patent Classification (IPC)7: E01C 21/00, G01F 11/02 (86) International application number: PCT/AU9900/092 (87) International publication number: WO 9942/665 (26.08.1999 Gazette 1999/34)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 17.02.1998 AU PP183498 (71) Applicant: Adelaide Brighton Limited Adelaide, S.A. 5000 (AU)	(72) Inventors: MARTIN, Guy, Kenneth Nuriootpa, S.A. 5355 (AU) BENSON, Stephen, Lester Gawler River, S.A. 5118 (AU) McAULEY, Richard, William Tumbi Umbi, NSW 2261 (AU) (74) Representative: Senior, Alan Murray et al J.A. KEMP & CO.,14 South Square,Gray's Inn London WC1R 5LX London WC1R 5LX (GB)