Gillnet Hauler Product

Overview

A gillnet hauler is a compact powered deck machine designed specifically for hauling anchored gillnets aboard commercial fishing vessels. Unlike the larger Trawl Winch (used for trawl fishing) or Net Drum (for seine/trawl storage), the gillnet hauler operates at low speed (0.5–2 m/s) and moderate load (5–15 tonnes max), accommodating the relatively light but long (100–500 m) and delicate anchored nets used in gillnet fisheries.

The system centers on a small Haul Drum (0.5–0.8 m diameter) that directly winds the gillnet anchor line. A Hydraulic Motor (10–20 hp, variable displacement) drives the drum via a flexible coupling. Paired Guide Roller units positioned on either side of the drum guide the anchor line smoothly onto the drum surface, distributing load and preventing rope jam. A Leveling System (finger or disc guides) ensures net spools evenly across the drum face. A spring-set Brake Unit, backed by a 3 L accumulator, holds the drum stationary between hauls.

Control is via a single-handle proportional Control Lever mounted within arm's reach of the hauling crew, integrated with the vessel's hydraulic pump system (typically 60–100 hp auxiliary diesel). An optional Stripping Knife can be mounted to scrape fish and algae from the net during hauling, preventing drumming and jam.

How It Works

Pre-haul preparation: The gillnet has been deployed from the vessel earlier in the day, anchored by weighted lines at both ends and floated along the top edge. The vessel approaches one anchor buoy, crew grapple it aboard and secure it to the hauler via a soft eye or shackle. The haul-drum is clear, the brake is disengaged, and the hydraulic system is pressurized by the main auxiliary pump (likely 60–100 hp diesel).

Hauling phase: The crew engages the proportional Control Lever, smoothly advancing it from neutral. The Valve Block directs pressurized oil to the Hydraulic Motor, which begins spooling anchor line onto the Haul Drum at 0.5–2 m/s adjustable speed. The Guide Roller units redirect the anchor line from vertical (coming up from the water) to tangent on the drum surface, avoiding edge cutting or line jump.

As the anchor line winds onto the drum, the gillnet itself follows, rising from the seabed toward the surface. The Leveling System (spring-loaded finger guides) automatically redistributes incoming net across the drum face width, preventing overload on one side. Crew stand by with grapnel hooks and hand-lines to guide the net aboard and secure it; they also begin picking fish from the net as it rises, a process called "shaking out" the catch.

Mid-haul strain: Partway through haul, the drum load may increase suddenly (net catches on bottom, snagged by rock or debris). The Hydraulic Motor displacement can be mechanically limited to prevent stalling; alternatively, the proportional valve includes a load-check function that modulates motor pressure, slowing haul speed automatically when load spikes. This prevents motor cavitation and hose rupture.

Optional stripping: If deployed, the Stripping Knife blade (hardened steel, 45° angle) contacts the spooling net on the drum surface, scraping off slime, small fish, and seaweed that would otherwise accumulate and jam the drum. Scrapings are washed overboard by seawater spray or fall into a collection tray.

End of haul: Once the net is fully aboard (5–15 minutes typical), crew secure the trailing anchor line with rope or chain around the drum to lock it in place. The operator releases the proportional lever to neutral, which both stops the motor and engages the Brake Unit (brake applies automatically, preventing drum freewheel in heavy weather).

Net processing: With the gillnet now coiled on the deck or in a net bin, crew manually de-tangle and untangle the mesh, removing fish and repairing tears with needle and twine. The net is then re-coiled, stored in a net locker, or immediately redeployed from the opposite anchor buoy for another soak.

Typical Gillnet Operation

• Vessel class: Gillnetter, 15–50 m length, 8–20 crew
• Net type: Bottom-set or drift gillnet, monofilament nylon, 100–500 m long, 3–10 m depth, mesh 2–5 cm
• Species: Salmon, herring, anchovy, cod, halibut
• Haul duration: 5–15 minutes per net (150–500 m)
• Daily nets per vessel: 2–10 depending on soak strategy
• Hydraulic integration: Shared with main fishing winch or auxiliary pump (60–100 hp diesel)

Portable Variants

Some small gillnetters (15–25 m) use portable or semi-portable haulers that can be quickly mounted and dismounted from deck rail hardware. This reduces weight aloft and allows crew to manually haul in light-sea conditions, extending the useful haul-season window. Portable models weigh 0.5–1 tonne and are hoisted by crane or davit.

Comparison with Alternatives

Manual hauling: Small gillnetters may haul entirely by hand—crew standing in a line, pulling hand-over-hand on the anchor line at 0.5 m/s. This is labor-intensive (requires 3–4 crew) and slow but eliminates motor complexity. Typical on very small (<15 m) or artisanal fisheries.

Slip rings (powered hauler without drum): Some gillnetters use a power-driven slip ring or capstan that rotates against the rope, creating friction-grip hauling. This avoids spooling and is simpler than a drum system but provides less control and can burn rope under heavy load.

Winch-based system: Larger gillnetters may use a Trawl Winch or similar multifunction winch for net hauling. This adds capability but complexity; the smaller dedicated hauler is preferred for focused gillnet operations.

Maintenance and Repair

• Weekly: Check brake accumulator pressure (100 bar target); inspect guide rollers for bearing looseness.
• Monthly: Drain hydraulic fluid sample (check for water and wear debris); inspect Haul Drum surface for rope burn or corrosion.
• Quarterly: Replace suction-strainer cartridge in main hydraulic circuit; re-adjust Leveling Fingers if net spooling becomes uneven.
• Annually: Motor displacement calibration; brake friction-disc thickness measurement; bearing seal replacement if oil leakage is visible.

Stripping-knife replacement: If deployed, the Knife Blade wears over several seasons and requires replacement or re-sharpening. A dull blade may clog rather than scrape, so annual inspection is recommended.

Safety Considerations

Rope entanglement: The rotating haul drum is a serious entanglement hazard. Guard rails or mesh screens must surround the working area. Loose clothing, hair, and jewelry are prohibited near the hauler. Crew training emphasizes keeping hands clear during operation.

Hydraulic pressure: The 200 bar system can cause serious injection injuries if a hose ruptures. Crew must never check for leaks with their hands; visual inspection only. Pressure relief is set to 250 bar to protect components.

Brake failure: If the brake fails to engage, the drum will freewheel in heavy weather, potentially dumping an uncoiled net overboard. A redundant mechanical lock (rope or chain securing the drum hub) is standard practice on deck.

Overload: Experienced operators can feel load through the proportional lever and avoid exceeding motor displacement. However, a Micro Switch limit-switch can optionally cut power and sound an alarm if load exceeds a preset threshold.