The Active Heave Compensation (AHC) capable winch accommodates 7350 meters of .681 EM cable, or 7500 meters of 9/16” cable. The winch powering scheme retains Rapp’s longtime redundancy approach, with three electric motors mounted on the gearbox; management is through VFDs (variable-frequency drives). One of Rapp’s newest winch control systems, the Pentagon Research system, will provide controls for the Active Heave Compensation (AHC). This newest technology has been popular in recent years, and it might well see heavy usage at deployments of up to 7000 meters of cable.
Matt Heintz, a Mechanical Engineer at Woods Hole Oceanographic Institution, first approached Rapp about the winch at the Underwater Intervention exhibition in February 2010. In 2011, he was one of several attendees of a blue-ribbon UNOLS delegation that visited Seattle in December for witness test of the LARS (launch-and-recovery system) for the ARRV. This year, Matt conducted field research of Active Heave Compensation-capable winches in the offshore oil industry as well.
“Rapp displayed a methodical approach to some complex problems on deck,” Matt observed. “I was impressed with technological choices and Rapp’s adaptability to evolving requirements. We executed several revisions of the specification in order to achieve a best fit.” Rapp will be delivering the winch in February 2013.