Laser Welded Duplex Steel I-Beam for a Luxury Yacht Tender Boom
On a luxury yacht, the tender has to be lifted off the deck, lowered into the water, and brought back onboard, and that movement runs through a boom that carries the load. For a project bound for Sweden, the boom was a special I-beam that also had to drive the lifting crane along its length. A marine environment is demanding: constant exposure to salt water calls for corrosion-resistant materials and components that hold their geometry over a long service life. The beam needed the right balance of size, weight, and strength, a corrosion-resistant grade, and a precisely machined top flange to take the crane mechanism.
A Corrosion-Resistant Boom with a Machined Top Flange
The beam works as the boom of a lifting system, so it had to combine structural performance with the durability a marine setting requires. Several requirements came together in one component. The cross-section had to be sized for an optimal balance of size, thickness, and weight. The material had to resist corrosion through constant exposure to sea water. The upper flange had to be machined on both ends before assembly and welding, so the geometry had to stay stable enough for precise machining. And the beam had to carry a toothed bar that moves the lifting crane along its length, which meant the top flange needed a clean, accurate surface for the mechanism to run on.
Lean Duplex S32304 with Laser and Laser Hybrid Welding
Austenitic stainless steel 1.4404 (316L) was considered first, then replaced by lean duplex steel 1.4362 (S32304) for its higher yield strength. The higher strength let the beam be made smaller and lighter, reducing both weight and cost while keeping the corrosion resistance a marine application needs. The finished I-beam measures 425 x 190 x 15 x 20 mm and is 5200 mm long, joined with full penetration welds. Laser and laser hybrid welding kept distortion to a minimum, so the top flange could be machined precisely and with less stock removal. The beam was then fitted with a laser-welded toothed bar with 5 mm penetration on each side, which is sufficient because the toothed bar carries no structural load.
Application Context
This case sits in Montanstahl’s shipbuilding segment, where laser welded special profiles are specified for marine components that need corrosion resistance and precise, stable geometry. A tender boom is a good example: it has to lift a load safely, carry a moving crane mechanism, and survive years of exposure to sea water. Laser and laser hybrid welding allow the section to be built from a corrosion-resistant duplex grade in a custom geometry tuned for strength and weight, and profiles like these are supplied worldwide to shipyards and yacht builders.