Rigging for jetty and marine construction: what survives salt water, tides and barges

Building a jetty, quay wall or marine outfall puts rigging in the worst environment on any site: wet, salty, abrasive, and moving. Piles and precast units are lifted from barges that pitch, lines are left rigged across a tide, and slings come out of the water carrying sand and salt. Hardware that would last years on a dry site can be rejected in months. This guide covers what to specify for marine works and how to keep it in service.

/01Galvanised or stainless.

For the heavy lifting on a marine job — piles, precast, steel — hot-dip galvanised carbon and alloy hardware is the norm: it is strong, rated and economical, and the zinc protects the steel through the splash zone. Stainless is the choice for small fittings that stay in salt water or salt air for years — handrail wires, mooring fittings, fixtures — but its ratings vary by maker and casting, and it costs more for the same load. Our guide to stainless vs galvanised rigging in the Gulf covers the trade-off, including galvanic corrosion where the two meet.

/02Pins that cannot back out.

Barge motion, wave action and tidal movement are exactly the conditions in which a screw pin can rotate and back out. Use bolt-type shackles — bolt, nut and cotter — for anything left rigged, and mouse screw pins with wire where a screw-pin shackle must be used. For heavy marine connections, wide-body sling shackles protect large slings on the bow. See how to rig a shackle correctly.

/03Slings in salt water.

/04Lashing on barges and pontoons.

Loads carried on barges — piles, precast, plant — must be lashed against the barge’s motion, which is a job for chain and binders or rated lashing hardware, not for whatever slings are spare. Use rated chain, load binders, lashing points and turnbuckles such as the Hamburger lashing turnbuckle, and check lashings as the tide and swell change. See ratchet strap vs chain and binder.

/05Marine standards on the drawing.

Marine and shipyard drawings often name DIN 82101 shackles (a German shipbuilding standard for lifting, towing and lashing) or European and BS patterns rather than US ones. Order to the drawing — see BS 3032, DIN 82101 and AS 2741 shackles. For mooring, see mooring bollards and anchor chain grades.