Home | Contact ST  
Follow ST

Feature Article

Where Winch Technology Meets Underwater Solution Expertise

By Klaus Brix

MERMAC winches often form part of a complete launch-and-recovery system used by work-class ROV operators who aim to offer their clients optimal system safety and operational efficiency.
Undoubtedly, one of the most widely used types of equipment across all marine contexts and industries would have to be the winch. No matter if you are hoisting the headsail on a yacht, lowering the anchors on a navy destroyer, launching delicate oceanographic instrumentation, deploying and handling an ROV, operating a deepwater seafloor drill or towing a side scan sonar, a winch is more than likely to be involved.

This seemingly insignificant and often taken-for-granted piece of machinery is simply used everywhere, and it is particularly critical for launching, handling and recovering underwater vehicles and systems. In spite of this, whenever an AUV looks for wreckage debris at record-breaking depths or when an ROV successfully clamps a leaking subsea oil installation or discovers and identifies an ancient shipwreck not many references are made to the winch systems that facilitated and safeguarded the journey of these sophisticated vehicles between vessel deck and seabed. These marine winch systems are, however, more than meets the eye, and definitely more than just a motor and spool.

The Modern Marine Winch
Increasingly sophisticated cable technology, expensive high-tech payloads and a general industry desire to optimize cost-intensive shiptime have rendered the system-handling requirements for winch systems and other types of deck equipment even more critical. A closer look at a modern marine winch system will swiftly reveal the extent of technology and engineering that has gone into creating systems that are fully abreast with the advanced underwater machines they are called upon to support. Specifically, marine winches are often required to precisely monitor various operating conditions, such as cable payout length, tension and speed. They are designed to offer advanced features, including active heave compensation (AHC), automated profiling, an integrated cable cleaning system, a remote control, advanced programmable logic and a graphical user interface (GUI).

Merging Winch Technology And Underwater Expertise
One of the well-established players when it comes to marine winch technology systems, is the MacArtney Underwater Technology Group (Esbjerg, Denmark)—an international supplier, manufacturer and integrator of underwater products, systems and solutions.

MacArtney is also a dedicated and innovative winch supplier, designing winches and A-frames for all types of requirements. With more than 500 solutions delivered since 1986, MacArtney systems are continuously involved in the launch and recovery of ROVs, towed systems, corers, drills, pumps, diving systems and many other equipment types under demanding conditions across the globe.

While the company's winch and handling systems are among the most advanced, rugged and operator-trusted solutions available, the real strength of the MacArtney winch portfolio is its pedigree and heritage of underwater technology and solution expertise. With a portfolio spanning from electric wet and dry mate connectors, cables and terminations to telemetry, subsea fiber-optics, cameras, ROVs and custom instrumentation platforms, MacArtney engineers know from experience what to demand from a winch when handling specific equipment types under harsh marine conditions.

Standard or Custom Winch Systems
Most MacArtney winches are based on proven standard designs, and this offers many advantages to customers, including reduced delivery time, cost and spare-part standardization. However, while standard winch and handling systems are suitable for most applications, certain jobs, equipment types or operational environments call for customized or even tailor-made systems. MacArtney has supplied a broad range of such systems and offers professional design and engineering support for all kinds of customer projects. The common denominator involves the close cooperation between winch engineers and the client to identify the exact technical needs and expectations.

Examples of specially designed winch solutions include underwater winches, Arctic winches, military specification winches and complete vessel moon pool handling systems. MacArtney also supports a full range of A-frames, integrated launch-and- recovery systems (LARS), winch ancillary products, service programs, testing and offshore support.

MacArtney specializes in electric winches and supports two primary winch ranges. The CORMAC range covers stainless steel portable and modular winches, and the MERMAC range comprises advanced systems for ROV, subsea, oceanographic and general purpose equipment handling. One of the key features and benefits of a MERMAC winch is the combination of powerful electric winch drive and AHC.

Electric AHC Winch Systems
In essence, the purpose of AHC is to keep a load, held by a vessel, motionless with regard to the seabed, hereby allowing operators to sustain subsea equipment operation, even during adverse weather conditions and higher sea states. AHC is enabled by using the data from a motion reference unit (MRU) to detect vessel displacement (heave, pitch and roll). A PLC control unit on the winch system then applies advanced algorithms to calculate how the winch system is to respond to and compensate for the movement. To continue this article please click here.

Klaus Brix received his degree in mechanical engineering from the University of Aarhus in 1999 and earned a diploma in business administration and marketing management from the University of Southern Denmark in 2005. Since 2009, Klaus has worked as a sales manager for MacArtney launch-and-recovery systems, winches and slip rings.

-back to top-

-back to to Features Index-

Sea Technology is read worldwide in more than 110 countries by management, engineers, scientists and technical personnel working in industry, government and educational research institutions. Readers are involved with oceanographic research, fisheries management, offshore oil and gas exploration and production, undersea defense including antisubmarine warfare, ocean mining and commercial diving.