Submergible apparatus for underwater operations

Claim 1

IN OFF SHORE, UNDERWATER OPERATIONS, THE METHOD OF PROVIDING A SUBMERGED, WATERTIGHT ENCLOSURE FROM WHICH WORKMEN PERFORM MANUAL OPERATIONS ON A SUBMERGED STRUCTURE COMPRISING: EMBEDDING IN A SUBMERGED BOTTOM THE LOWER END OF A PIPE-LIKE STRUCTURE HAVING AN AXIAL BORE OF SUBSTANTIALLY UNIFORM INSIDE DIAMETER EXTENDING COMPLTELY THERETHROUGH, THE UPPREEND OF SAID PIPE STRUCTURE LYING BELOW THE SURFACE OF THE WATER; PROVIDING A HOUSING A HAVING AN IN ITS BOTTOM; SINKING SAID HOUSING IN A GUIDED PATH DOWN TO SAID PIPE STRUCTURE; RELEASABLY ENGAGING THE PERIPHERY OF SAID OPENINGWITH THE UPPER END OF SAID PIPE STRUCTURE AT A LOCATION BELOW THE UPPER END OF THE BORE OF SAID PIPE STRUCTURE SO AS TO FORM A CHAMBER AND SO THAT THE BORE COMMUNICATES WITH SAID CHAMBER THROUGH SAID BOTTOM OPENING AND SO THAT SAID HOUSING IS SUPPORTED BY SAID PIPE STRUCTURE AGAINST MOVEMENT IN A DIRECTION AXIAL THERETO; EFFECTING A WATERTIGHT SEAL BETWEEN SAID HOUSING AND SAID PIPE STRUCTURE; PROVIDING ACCESS FOR WORKMEN, TOOLS AND EQUIPMENT BETWEEN SAID CHAMBER AND THE SURFACE OF THE WATER; PERFORMING OPERATIONS MANUALLY AT THE TOP OF SAID PIPE STRUCTURE FROM A LOCATION WITHIN SAID CHAMBER ADJACENT AND ABOVE THE TOP OF SAID PIPE STRUCTURE; AND REMOVING SAID HOUSING FROM THE TOP OF SAID PIPE STRUCTURE.