Crane is able to carry on even with 20-foot waves
This story profiles one of the Offshore Technolog y Conference’s Spotlight on New Technolog y Award winners.
When moving heavy loads from ship to an offshore installation, even small motions of a vessel can have big consequences. Barge Master, a Dutch company with 20 employees, has found a way to compensate for those movements in the heaviest of seas.
Barge Master is the smallest company to win a Spotlight on New Technology award. Its BM-T40 motion-compensated crane stands on hydraulic cylinder legs that respond individually to the movement of its host vessel, allowing it to lift up to 40 tons in seas with 15- to 20-foot waves. This represents a significant breakthrough, particularly for waters like the raucous North Sea, where Barge Master does a lot of its business.
“The T40 enables the ship to work more than 90 percent of the year,” says Eelko May, Barge Master’s technical director. “Other vessels can be limited to 50 to 60 percent. Sometimes these lifting operations are not possible at all.”
The T40 follows a much larger predecessor introduced in 2009, the T700, capable of loads up to 700 tons and used primarily during construction of offshore installations. Barge Master started work on the T40 in 2013 after Shell requested a smaller version for maintenance, major repairs and restarts.
Traditionally, operators build a crane into each rig for the heavy lifting. With one T40 on one vessel, Barge Master can service 15 platforms, saving tens of millions of dollars in crane installation and maintenance costs.
The industry is stripping down satellite platforms of all extraneous equipment and personnel, and moving all vital systems and equipment to one central platform.
May says that in the future, most platforms will not have a helicopter deck and a crane.
Instead, work will be done from support vessels.
The T40 can be installed on any ship. The motion compensation technology, which is more robust than the original T700, uses inclinometers to measure the motion of the ship, so if the bow pitches down, the hydraulic cylinder legs of the crane extend to compensate, keeping the load steady.
The inclinometer is installed in triplicate, for added redundancy.
“It’s very important that the system always works,” May says.
“You can imagine if the crane starts to move with the ship.”