BISSO MARINE REFLOATS 10,000 TONS

The wrath of Hurricane Katrina left a 400’ x 138’, drydock loaded with a 120,000 BBL oil barge, combined weighing almost 10,000 tons, grounded in the Industrial Canal in the New Orleans area.

BISSO MARINE was contracted by BOLLINGER SHIPYARDS to perform the refloating. The drydock was comprised of four individual drydock pontoons; the pontoons were connected by the shipyard to accommodate the large oil barge. Consequently, the challenge for the salvage team was to solve the problem of refloating four drydocks with one barge straddling all four.

The salvage team was mobilized and commenced exhaustive diving and surveying operation. The salvage team worked for 70 days to repair damage and prepare the drydock for an extraordinary pulling force. The BISSO MARINE salvage team, led by Ken Edgar, Sr. Salvage Engineer, devised a plan to interconnect the four drydock pontoons.

With a refloating plan in place, BISSO MARINE collaborated with VERSABUILD and co-engineered four specialized pulling barges to provide a 3,200 ton pulling force. The challenges of the operation were further compounded by the narrow waterway outboard of the grounded drydock. The channel width was <400’. To overcome the insufficient channel width, BISSO MARINE engineered a mooring plan to bury anchors across the channel in a rock yard which is operated by PONTCHARTRAIN MATERIALS.

BISSO MARINE contracted BOH BROS for logistical and ground preparation support at PONTCHARTRAIN MATERIALS which included the burial of eight anchors (22,000 lbs – 40,000 lbs) several hundred feet inshore.

The salvage team fabricated toggle beams and bolsters at four locations to serve as the pulling points on the drydock. The pull barges were connected to the toggles and then connected to an equalizing bridle made of 4” anchor chain which was connected to the buried anchors.

Once the drydock was refloated, salvage teams conducted some repairs to the drydocks pontoons then shifted the drydock and oil barge into the deeper channel and lowered the drydock to refloat and deliver the oil barge.