Conduit section

Claim 1

APPARATUS ADAPTED TO BE CARRIED BY A VESSEL UNDERWATER MINING AT GREAT DEPTHS BENEATH THE SURFACE OF THE SEA COMPRISING A RIGID INTEGRAL CONDUIT SECTION HAVING A GENERALLY UNIFORM CROSS SECTIONAL THICKNESS AND A SUBSTANTIALLY UNIFORM CYLINDRICAL BORE FORMED LONGITUDINALLY THERETHROUGH, SAID SECTION INCLUDING AN UPPER HANDLING PORTION FORMED ON THE UPPER END THEREOF AND A LOWER HANDLING PORTION FORMED ON THE LOWER END THEREOF, EACH OF SAID HANDLING PORTIONS EXTENDING RADIALLY OUTWARDLY THEREOF AND PERIPHERALLY AROUND SAID SECTION, SAID SECTION INCLUDING AN INTEGRAL COLLAR PORTION DISPOSED ADJACENT TO SAID UPPER HANDLING PORTION, SAID COLLAR PORTION EXTENDING RADIALLY OUTWARDLY OF SAID PERIPHERY AROUND SAID SECTION, SAID SECTION INCLUDING A FIRST CIRCUMFERENTIALLY EXTENDING PORTION OF GREATER WALL THICKNESS THAN SAID UNIFORM CROSS SECTIONAL THICKNESS INTERMEDIATE SAID UPPER HANDLING PORTION AND SAID COLLAR PORTION, SAID SECTION INCLUDING A SECOND CIRCUMFERENTIALLY EXTENDING PORTION OF GREATER WALL THICKNESS THAN SAID UNIFORM CROSS SECTIONAL THICKNESS ADJACENT TO BUT SPACED ON THE OPPOSITE SIDE OF SAID COLLAR PORTION FROM SAID FIRST CIRCUMFERENTIALLY EXTENDING PORTION OF GREATER WALL THICKNESS, SAID PORTIONS OF GREATER WALL THICKNESS BEING OF SUBSTANTIALLY THE SAME AXIAL EXTENT, SAID CIRCUMFERENTIALLY EXTENDING PORTIONS OF GREATER WALL THICKNESS SERVING TO REINFORCE THE CONDUIT SECTION TO PROVIDE ADEQUATE STRENGTH AND RIGIDITY WHEN SUBJECTED TO BENDING MOMENTS TO SAID LAST-MENTIONED HANDLING PORTION AND SAID COLLAR WHICH ALSO COMPRISES A HANDLING PORTION OF THE CONDUIT SECTION.