05 Apr 2022 From supertankers to speedboats, aluminium floats the boat in the maritime industry

In 1892, France introduced to the world the first all-aluminium seagoing vessel, a 40-feet long yacht. And with time, aluminium’s preference as the material of choice for maritime applications has only increased. Why? Because aluminium’s exceptional design flexibility, high resistance to corrosion and light weight, make it the darling of the international maritime industry.

Aluminium is a versatile material, meaning its shape and size can be modified to suit any number of applications like plates, sheets, rods and extrusions, without the risk of breaking or cracking, thanks to its inherent strength. Further, being light in weight, aluminium decreases the dead weight of the ship, thus allowing for higher speeds, greater manoeuvrability, more stability, ability to carry more payload or cargo, travel longer distances, reduce fuel consumption, and thereby, emissions. Its popularity stems from the fact that substituting aluminium for steel in marine construction can lead to weight savings of up to 45% in hulls and up to 65% reduction in superstructures.

Sailors across seas operate in all kinds of harsh conditions. They need to sail in stormy weather, expose their boats to abrasive saltwater, humid climate, and often travel from hot to cold climes within the same trip on longer shipping routes. Given that aluminium is naturally resistant to rust and corrosion, it is an ideal metal for constructing the boats that are exposed to all of these conditions on a regular basis. When alloyed, aluminium’s non-corrosive properties can be enhanced manifold. Additionally, its natural corrosion resistance also means lower maintenance, and therefore, more cost savings.

Boats of all sizes, from gigantic supertankers to nimble speedboats, now make use of aluminium to varying degrees. Aluminium usage in large vessels can range from 2,000 tonnes to as high as 4,000 tonnes, and may be even more! Even smaller boats, such as catamarans, navy vessels, and ferries make use of aluminium to a significant level. One of the largest aluminium vessels in the world, a 130-m catamaran is being built in Tasmania presently. Once complete, it is expected to hold up to 2100 passengers and 220 cars in one go!

Technological advancements have significantly reduced the labour involved in creating aluminium-alloy based ships. Besides fuel and cost savings, yet another advantage of aluminium vessels is that at the end of life span, it has significant salvage value, since aluminium is 100% recyclable. Unsurprisingly, experts predict that aluminium could potentially replace steel as the primary construction material for ships in the near future.