In addition, engineers needed to ensure they fully understand the so-called boundary layer physics – the places where the ship, bubbles and water meet.
“The ironic thing is that even though the ships are very large, the region near the metal surface that actually ends up making up a lot of the skin friction is on the order of less than one tenth of a millimetre. That ‘very near wall flow’ is where all the bad stuff happens to cause friction” says Ceccio
The physics is complicated, and has taken a long time to perfect. But the set-up itself is physically pretty simple though. Engineers install openings on a flat-bottomed hull connected to a compressor on the deck. The trick is then injecting just enough air. Too little and there is no improvement, too much and you get no extra benefit. Get it right and the gas starts to collect under the ship allowing it to glide along.
Recently Mitsubishi Heavy Industries have started to commercialize what it calls the “Mitsubishi Air Lubrication System”. Sea trails have shown a 10% reduction in CO2 emissions, whilst computer models of more efficient hull designs suggested there could be a reduction of up to 35%. And already orders have been placed for huge new ships using the technology. Late last year, grain conglomerate Archer Daniels Midland ordered three giant dry-bulk carriers with innovative hull shapes, propulsion systems and the lubrication technology. It claims the designs will help reduce CO2 emissions by up to 25%.
The trio will be launched in 2014, some of the first ships of the post-Panamax era. Exactly 100 years after the Panama canal first revolutionized shipping, its redesign looks set to do it again.