Method and apparatus for salvaging underwater pipelines

A method of salvaging a pipeline in a marine environment, comprising the steps of:

• a) providing a frame having a perimeter that surrounds first and second cutting blades, each blade having a first planar surface and a second surface with a beveled cutting edge, the flat, planar surfaces being in closely spaced abutting relationship during cutting, the frame having a gate that enables the frame to be selectively placed around or removed from a section of pipeline to be cut;
• b) placing the frame on the pipeline by first opening the gate and then closing the gate;
• c) moving the first cutter blade toward the second cutter blade using hydraulics and until they overlap;
• d) wherein each cutter blade has a notched, v-shaped cutting edge;
• e) wherein in step “d” the pipeline is centered before being cut by each v-shaped cutting edge;
• and
• f) using the fixed blade and guides in the frame to prevent movement of the first blade in a direction perpendicular to the fixed blade.

A marine pipeline salvaging apparatus, comprising:

• a) a frame having a perimeter that surrounds a pair of opposed cutting blades, each cutting blade having a flat, planar surface and an opposing surface with a beveled cutting edge, the frame having a gate that enables the frame to be selectively placed around or removed from a section of pipeline to be cut and salvaged;
• b) a lifting apparatus for lifting and placing a frame on the pipeline to be salvaged;
• c) one of the cutting blades being powered with hydraulics to move toward the other, until they overlap;
• d) wherein one of the blades is a fixed, non-moving blade and each blade has a notched, v-shaped cutting blade;
• e) means for automatically centering the pipeline to be salvaged within the respective notched, v-shaped blades prior to being severed as the blades advance relative to one another;
• and
• f) guides that hold the flat, planar surfaces of the blades together in an abutting, closely spaced face-to-face relationship, preventing deflection of the moving blade relative to the fixed blade in a direction that is lateral to the direction of travel of the moving blade.

A marine pipeline salvaging system, comprising:

• a) a frame having a perimeter;
• b) first and second cutting blades mounted to the frame, each blade having a first planar surface and a second surface with a beveled cutting edge, the flat, planar surfaces being in closely spaced abutting relationship during cutting;
• c) a gate that enables the frame to be selectively placed around or removed from a section of pipeline to be cut;
• d) a lifting device that enables placement of the frame on a pipeline by first opening the gate and then closing the gate;
• e) wherein the first cutter blade moves toward the second cutter blade using hydraulics and until they overlap;
• f) wherein each cutter blade has a notched, v-shaped cutting edge;
• g) wherein the pipeline is automatically centered before being cut by each v-shaped cutting edge;
• and
• h) guides on the frame that prevent movement of the first blade in a direction perpendicular to the fixed blade.