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1 January 2011 Sidewinder: Description of a New Block Winch for Deploying Instruments at Sea
Molly Sturdevant
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We describe a new electric winch design and its functionality for conducting research operations off different-sized vessels. Currently, several small oceanographic winches are available for deploying research instruments and nets, but they are typically heavy, noisy, semipermanently mounted to the deck, hydraulically operated, and not readily transferable between vessels. The limitation of winch portability between vessels, in particular, has been exacerbated by the increasing use of a variety of chartered vessels to conduct state and federal agency and university research. To address these challenges, we developed a relatively lightweight (70 kg), portable block-design winch that is spooled with 400 m of plasma line, powered by two 12-V marine batteries, and operated by a remote control box on a pendant equipped with a joystick. The 2.2-kW drive produces 100 kg of line pull at speeds of 0 to 2.0 m/s. The pendant includes digital displays for line speed, scope, and angle as well as an emergency stop. Nicknamed the “Sidewinder,” this winch is quiet, can be operated by one person, and is suspended outboard from a davit or crane boom, increasing available deck space and relocating all lines safely away from vessel personnel. On vessels 7 to 50 m in length the Sidewinder has been successfully tested for deploying small gear such as conductivity—temperature—depth profilers and large BONGO plankton nets that require specific deployment and retrieval speeds and line angles. To ensure safe operation, vessel support features such as the power system and davit working load capacity should be considered when the Sidewinder is custom-built.

Winch technology has undergone many developments in recent decades as marine nearshore research and commercial applications have expanded (Mulcahy 1981; Dempke and Griffin 1997; Bash 2001). Research protocols for deploying instruments and nets have also changed over the years, following comparisons of sampling methods and gear (Pepin and Shears 1997; Weinberg et al. 2002; Baumgartner 2003) and advances in the design of net sampling systems (Siler 1983; Choat et al. 1993), oceanographic sampling instruments (Rudnick and Klinke 2007), remotely operated vehicles, and hydroacoustic equipment. Development of increasingly complex sensoring systems has required integration with electronic, mechanical, and hydraulic systems (Dempke and Griffin 1997; Gordon et al. 1998; Hooker and Maritorena 2000). For commercial and deep-sea applications, new deck machinery to handle deeper and heavier loads in heavy seas has required more winch power and performance (Griffin and Nishimura 2007; Griffin 2009). This report describes a versatile new small winch application for meeting research needs to accurately deploy oceanographic instruments and small nets and that can be readily transferred among vessels, particularly smaller ones.

Existing winches available for deploying oceanographic equipment are not readily transferred between vessels used as sampling platforms to study shallow marine nearshore processes. Common winches still operate by hydraulics and are semipermanently mounted to the deck of a vessel (Dempke and Griffin 1997; Markey Machinery 2004). This limitation has been exacerbated by the increasing use of chartered vessels to conduct research; for example, scientific monitoring programs may conduct routine surveys from several different platforms during the season, each requiring the transfer of gear. In Alaska, the Southeast Coastal Monitoring project (SECM; conducted by the National Marine Fisheries Service, Auke Bay Laboratories) formerly used National Oceanic and Atmospheric Administration (NOAA) vessels exclusively for research, but now conducts its annual surveys using a variety of chartered vessels of different sizes. Project personnel recently collaborated with Markey Machinery (Seattle) to develop the new winch (subsequently dubbed the “Sidewinder”) design to address challenges in deploying sampling gear among various vessels.


Schematic diagram of the COMB-01 Sidewinder Research Winch (Markey Machinery 2010) showing construction details and mechanical, electrical, and instrumentation features (American National Standards Institute specifications).


The SECM conducts annual surveys to sample juvenile Pacific salmon Oncorhynchus spp., their predators, Zooplankton prey fields, and physical oceanographic features in northern Southeast Alaska (Orsi et al. 2004). Sampling is conducted monthly from May to August at stations within a few kilometers of shore, typically at 50–300 m deep. During this work, a variety of small oceanographic instruments and nets are deployed from NOAA and chartered vessels from 7 to 50 m in length. Vessel configuration varies widely, and sampling operations must be adapted to vessel layout, space limitations, and permanent machinery. Fish trawling is accomplished with a Nordic surface trawl that requires large winches and reels typically located amidships. Oceanographic sampling requires smaller winches that are typically mounted on one side or on an upper deck. Some vessels do not have a winch of the appropriate size or location to conveniently deploy small instruments according to standard specifications. In these instances, the SECM project has provided a small hydraulic winch with a separate electronic display showing meters of line out. However, this winch is relatively heavy and nonportable, and requires a semipermanent mounting location near hydraulic lines. Like many winch systems, the rigging is directed through a remote block on a davit or boom that pivots to one side, where the sampling gear is attached. In addition, this winch is inconvenient because several staff are needed to monitor its operation and coordinate with vessel power to meet specific sampling gear requirements (e.g., BONGO net deployment and retrieval at defined speeds and line angles; Orsi et al. 2004). The operator uses winch-mounted controis a second person reads line speed from an electronic display located away from the winch, and a third person monitors the line angle (40–50°) manually with an inclinometer.


Photograph of the Sidewinder block winch showing the aluminum housing of the drum below the (left to right) planetary reducer, brake, line guide, and motor and the lifting handles above.


In contrast to the summer surveys, which include fish trawling, the SECM survey in May is restricted to oceanographic sampling for which the laboratory's 7-m RV