Chet Morrison gets new dive support vessel

Diving operations to help lay oil pipelines are a big part of the services supplied by Chet Morrison Contractors.

The Houma oilfield services provider announced the company has built a new diving support vessel, one of the largest saturation-dive DSVs operating in the Gulf of Mexico.

Work on the 240-foot Joanne Morrison began in mid-October, said Brett Blanchard, vice president of subsea construction.

Diving support vessels stay afloat and deploy dive vehicles for undersea work through moon pools located in the boat.

The vessel, named for owner Chet Morrison’s mother, had formerly been a utility supply craft supporting drilling in the Gulf.

Blanchard said most of the boat’s retrofitting occurred at Bollinger in Amelia, but work was finished at Chet Morrison using the company’s own personnel and outside contractors, including diving industry supplier LexMar, based in Singapore.

The Joanne Morrison, which can accommodate 54 people working around the clock, was outfitted with new quarterings, anchors, cranes, auxiliary dive equipment and saturation diving system. As a supply craft, it could accommodate fewer personnel, Blanchard said.

The boat is the only saturation-dive DSV operated by Chet Morrison, although the company has a pipeline-laying barge with that capability. Chet Morrison owns three other DSVs, but they are used only for surface diving, Blanchard said.

Saturation diving is a way of lengthening time spent undersea. Divers absorb the gases they breathe inside dive vehicles, shortening decompression time.

The boat uses four-point mooring to remain in position in the open waters of the Gulf. Some boats use thrusters to remain stable instead of anchoring, but the Joanne Morrison uses them only in a support capacity, Blanchard said.

The boat, which employs winches to launch and retrieve dive vehicles, also has a second moon pool and a 70-ton hydraulic Mantis crane to support divers’ construction activity, according to Blanchard.

The Joanne Morrison, a 240-foot diving support vessel, is the latest craft completed by Chet Morrison, a Houma oilfield services provider. The vessel stays afloat and deploys dive vehicles for undersea work. * Photo courtesy of CHET MORRISON