Active Heave Compensation for an offshore crane

Active Heave Compensation for an offshore crane
Marginal Column

November 2017


For the first time, Bosch Rexroth delivered a system of Active Heave Compensation in the U.S. to be added to an offshore crane of lift boat builder EBI. The project was a challenge for both partners – technologically and because of a tight schedule.

Founded in 1949 as a universal repair service, Elevating Boats, Inc. (EBI) evolved into a lift boat specialist by developing an elevated barge to provide stable platforms for the oil and gas industry in the Gulf of Mexico. Today the company is based in Houma, Louisiana, operates 26 lift boats in the Gulf and is, according to its CEO Ken Serigne, “the only designer, builder and operator of lift boats.” EBI was approached by a client needing a telescopic box boom offshore crane with Active Heave Compensation (AHC) of the main winch. As it was a new area for EBI to be in, Bosch Rexroth was contracted for the job. It was the company’s first AHC project in the U.S.

Preferred Technology

AHC was the preferred technology because of its ability to compensate for the relative motion between the ship and sea bottom in offshore operations. It increases safety by reducing the influence of waves on the load being lifted and is realized with Rexroth’s dynamic winch drive system with speed and torque control of the main winch. The company supplied the hydraulic power unit, components, accumulators, winch hydraulic motors, load holding manifolds, mobile control valve assembly and controller. The Norwegian partner Scantrol provided the AHC controls.

Five Instead of 10 Months

The biggest challenge with the project was time. “This is a case of an impressively fast accomplishment,” states Joe Sabbia, applications engineer for Marine & Offshore industry at Bosch Rexroth. “We had to start with detailed engineering in the quotation phase. The entire project would normally take 10 months. We did it in five.” The timing was also achieved by designing a more simplified, efficient system with an open circuit hydraulic drive concept including the mobile pump A15 VLO 280 with high power density, and the mobile, flow sharing M7 valve . The project involved the three factions EBI, Bosch Rexroth and Scantrol working simultaneously on their own and then combining to put it all together – an intentional process that leveraged everyone’s individual expertise to then come together quickly.

Joining Forces Together

The project was a learning curve for everyone involved. Ken Serigne states: “This first AHC crane commissioned in the U.S. is a good example of state-of-the-art electronic controls being used in existing hydraulic concepts to make them smarter. We were doing things that we thought were impossible.” Teamwork was essential in the success of this project, with the three partners joining forces together.

Success Opens New Doors

The crane was constructed in Ponchatoula, Louisiana, and then traveled to Singapore for installation and final commissioning on board the vessel. Now, the vessel is operating in the Mediterranean. The crane supports offshore construction and diving operations and is working well. EBI sees this success as being important to its oil and gas industry business, but also as a way to expand into other industries and types of operations. Says Ken Serigne: “This crane opens a new door for us. We’ll put it on a variety of vessels worldwide and can use it to get into other types of construction projects on the water.”