ROV winches with AHC engineered for harsh environments

April 1, 2009
Rapp Hydema has introduced ROV winches with active heave compensation (AHC) for extreme conditions such as ultra deepwater and arctic areas.

Rapp Hydema has introduced ROV winches with active heave compensation (AHC) for extreme conditions such as ultra deepwater and arctic areas. The company already has orders from leading ROV contractors – in March, two units were being installed, and a further six were in production.

The winches are rated for operations down to 3,000 m (9,842 ft), although larger models for deeper waters are available, says market manager Tore Torrissen. All are fully certified according to DNV rules for the certification of lifting appliances.

Electric-powered ROV winch from Rapp Hydema.
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An AHC system is integrated into the winch control system. For this reason electric drive was specified for the winches, as it provides faster reaction times. But there are other benefits, according to Torrissen – electric drive is environmentally clean and offers somewhat better energy efficiency than hydraulic drive.

The new winches also come with up to four electric motors, so if one fails, the system can remain in operation.

The winch system incorporates the latest version of Rapp Hydema’s well-proven Pentagon control system, with significantly improved vehicle and cable handling characteristics. A user-friendly system operated with combined joy-stick and LCD touch screen, the system monitors cable length, tension and cable speed, and presents graphs of data related to the AHC mode.

The new winch range is a response to developing market needs. Following feedback from customers about problems spooling the ROV umbilical with the necessary back-tension on the winch-drum, Rapp Hydema has acquired a spooling facility, allowing it to provide this service itself.

Additionally, the company offers a conversion service to turn hydraulically driven ROV winches into electrically driven units complete with AHC. Two such conversions have been carried out.

Rapp Hydema is based in Bodø on the coast of northern Norway, within the Arctic Circle. Its expertise in marine winches comes from a background supplying the Norwegian fishing industry.

“We are used to the rough sea conditions and the cold, and this is reflected in our technologies,” says Torrissen.

The company also has developed multi-handling winches for subsea lifts. For all its products, it provides a full service, including all necessary documentation. In addition, company engineers perform start-up and training of winch operators.