Method and apparatus for cleaning, viewing and documenting the condition of weldments on offshore platforms

• US 4,502,407 A
• Filed: 04/12/1982
• Issued: 03/05/1985
• Est. Priority Date: 04/12/1982
• Status: Expired due to Term

• Current Assignee: Shell Oil Company (Shell Plc)
• Original Assignee: Shell Oil Company (Shell Plc)
• Inventors: Stevens, James W.
• Primary Examiner(s): Blix, Trygve M.
• Assistant Examiner(s): Swinehart, Edwin L.
• Application Number:
  US06/367,488
• Time in Patent Office: 1,058 Days
• Field of Search: 114/222, 114/312, 114/322, 114/321, 114/330, 114/338, 294/66 A, 405/185, 414/1, 354/112, 354/113, 352/131, 352/132
• US Class Current: 114/222
• CPC Class Codes: B63C 11/52 Tools specially adapted for working underwater, not otherwise provided for
• CPC Class Codes: B63G 2008/007 by means of a physical link to a base, e.g. wire, cable or umbilical
• CPC Class Codes: B63G 8/001 Underwater vessels adapted for special purposes, e.g. unmanned underwater vessels; Equipment specially adapted therefor, e.g. docking stations self-propelled or direction controlled diving chambers with mechanical link to a base B63C11/42
• CPC Class Codes: E02B 17/0034 Maintenance, repair or inspection of offshore constructions

Abstract

A subsea platform inspection vehicle on a power tether cable adapted to be propelled through the water and lock onto an underwater member of a platform adjacent a welded joint and provided with a jet to clean a weld and a television camera to observe the condition of the weld.

Claims

1. An underwater vehicle adapted to be operated from a remote location above the surface of a body of water through a power- and signal-transmitting tether cable, said vehicle being adapted to be propelled through said water to an underwater steel structure to clean and inspect welds in said structure, said vehicle comprising:

housing means adapted to be secured to a tether cable;

remotely-actuatable power-actuated thruster means carried by said housing means for propelling said housing means in any direction;

remotely-actuatable television camera means carried by said housing means for viewing at the surface the illuminated water area near the housing means;

light means carried by said housing means for illuminating the area adjacent said television camera means;

buoyancy means carried by said housing means for maintaining said housing means at a buoyancy of no less than neutral buoyancy;

remotely-actuatable vehicle anchoring means mounted on said housing means for anchoring said housing means to an underwater structure;

remotely-actuatable flexible, pivotable, articulated arm means having one end of said arm means affixed to and carried by said housing means, said arm means being on the same side of said housing means as that carrying said television camera means;

said articulated arm means being elongated and having a plurality of interconnected short rigid arm segments, with the outermost segment being the terminal segment;

remotely-actuatable metal-cleaning apparatus carried by the terminal arm segment of the arm means to form cleaning arm means for cleaning a selected portion of an underwater steel structure;

remotely-actuatable camera means carried by the arm means to form viewing arm means for viewing at short range and within the range of the cleaning arm means an area of interest on said underwater steel structure;

said camera means carried by said arm means comprising a stereoscopic camera and a photoflash unit; and

a remotely-operable telescoping prod extending outwardly from the camera to the object being photographed.

2. Apparatus adapted to be used with a remotely-controlled underwater vehicle operating on a tether cable from a remote location to clean, view and photograph selected area of an underwater structure, said apparatus comprising:

a tool body adapted to be secured and operatively connected to the lower portion of said underwater vehicle;

remotely-actuatable anchoring means operatively carried by said tool body;

a remotely-actuatable, flexible, pivotable, articulated cleaning arm extending from said tool body;

a cavitation jetting tool carried at the extended end of said cleaning arm;

a remotely-actuatable, flexible, pivotable, articulated viewing arm independent of said cleaning arm and extending from said tool body;

remotely-actuatable television camera means and its associated light means carried at the end of said viewing arm; and

remotely-actuatable photographic camera means and its associated light means carried at the end of said viewing arm adjacent to said television camera means.

3. The apparatus of claim 2 wherein the photographic camera means is a stereoscopic camera and the light means therefor and operatively connected thereto and operable therewith is a strobe light source.

4. The apparatus for claim 2 including hose means in communication between said cavitation jetting tool and a source of pressure fluid.