Aquaculture 1x7 Galvanized Steel Strand 6-10mm Heavy Zinc Longline Rope

Aquaculture 1x7 galvanized steel strand, 6mm to 10mm, for longline and grid mooring work that sits in seawater year round.

Sea farmers are hard on steel. A longline runs from a shore anchor out across a bay, holds crop and current load, and sits in salt water, silt and biofouling for years. Galvanized strand survives this better than most people expect, but only if the coating is heavy enough and the water is not strongly anaerobic.

In sulphate rich mud, steel can suffer bacterial corrosion at a rate that surprises anyone used to open water figures. We are honest about that limit and quote the coating mass so the buyer can plan replacement intervals rather than assume the rope is permanent. In the water column the same strand holds up well, and in the splash zone it performs better than any bare or painted alternative at this price.

• Heavy coating for continuous immersion: Three hundred to four hundred grams per square metre, which is roughly double a standard outdoor coating. Immersion service consumes zinc, and the thicker the layer the longer the interval before inspection matters.
• 1x7 stiffness holds a longline grid: Seven wire strand does not stretch like a synthetic line and does not creep, so the longline grid geometry holds and crop lines stay where they were set.
• Small enough to handle by hand: From 6mm up, the strand can be handled and tensioned with standard grips and shore winches without specialist equipment, which matters on a working farm.
• Coating mass stated per lot: Measured by stripped weight and printed on the certificate. A buyer comparing two prices should compare this figure first, because coating mass is most of the cost difference.
• Available with served or welded ends: Longline runs are cut on site. Ends are served before packing so the crew is not fighting a birdcage at the shore anchor in a wind.
• Honest service limits: We publish that sulphate reducing bacteria in anaerobic mud accelerates corrosion, and recommend heavier sections or a different material at the mud line. That is more useful than a claim that the product lasts forever.

The main use is oyster, mussel and seaweed longline systems, including shore anchors, backbones and grid moorings. It is also used for farm frame tensioning, walkway handrail stays and predator net anchoring on inshore sites.

Because the strand is stiff and non creeping, it also suits floating pontoon and service barge mooring grids where a synthetic line would stretch under tidal load and let the structure drift.

• Oyster, mussel and seaweed longline backbones
• Shore anchor and grid mooring strand
• Farm frame and walkway tension stays
• Predator net and bird net anchoring
• Pontoon and service barge mooring grids

Coating mass is measured by stripped weight on samples from both ends of each lot, and breaking load is tested per lot. Seawater immersion samples are held in a flow tank and inspected at three month intervals, with the corrosion rate logged so we can give buyers a real number rather than a guess.

Strand is inspected for coating skips at wire crossover, which is where immersion corrosion starts. Reels with visible skips in the outer layer are rejected, because in a wet environment a single pinhole becomes a wire break within a few seasons.

Wooden or iron reels of 500m to 2000m, or coils strapped for boat transport. Reels are marked with size, length, coating mass and lot number in waterproof marking, since paper labels do not survive a season on a dock.