Intelligent Solution Increases Capability of Dive Bell System

Red Marine, based in the North East of England, has developed and delivered two shock absorber systems to Subsea 7, a global offshore contractor.

Each system – to be installed on the Osprey Dive Support Vessel later this year – is a custom unit with a shock absorber and winch line tensioning system to enhance the protection of the dive bell and handling system during launch and recovery operations. 

Joe Orrell, Managing Director at Red Marine said, “We are delighted to have developed such an advanced hydro-mechanical system that will ultimately save Subsea 7 time and money through enhancing the capability and lifespan of the Osprey vessel.

“As a progressive and supportive engineering house, we have worked closely with Subsea 7 – as we do with all clients – to deliver a solution that meets their specific requirements. This is achieved through collective and intelligent thinking combined with the ability to rapidly take a viable concept through to design, manufacture and testing.”

The shock absorbers are designed to reduce shock loading on the lift winch wire caused by the differential motions of the vessel and the diving bell. In operation, a maximum acceptable line tension is set and once this value is reached a shock absorbing cylinder extends releasing extra wire length - up to 3.2m - into the system reducing line tension in a controlled manner down to an acceptable level.

Further to this, an advanced slack management capability ensures wire tension will stay above a minimum acceptable level if the vessel and bell move towards each other, reducing the risk of snatch loadings on the system. 

Certified in accordance with stringent DNV codes for diving launch and recovery systems, each dive bell shock absorber system weighs 4.3 metric tons and has been manufactured using Red Marine’s proven supply chain.