Building a ship to carry fish as passengers may seem like a phenomenal case of missing the point, but Rolls-Royce has signed a £5.8 million (US$9.5 million) contract to design and equip one that does just that. The live fish carrier will be built by Turkey's Tersan shipyard for the Faroese salmon farming company Bakkafrost as a way to carry fish from their pens to the processing plant.

According to the Food and Agriculture Organization of the United Nations, salmon farming has grown by a factor of ten since 1982. This is great news for people who love salmon, but also exacerbates a logistical problem. The rivers, estuaries, and fjords that are best suited for salmon pens are often in locations that are less than ideal for siting a processing plant, so bringing in farmed salmon can face the same difficulties as transporting wild-caught ones from fishing grounds.

Just scooping up the fish with a net and pouring them in a hold for even a short trip risks bruising or stressing them, and it poses ethical issues. On the other hand, salmon farming operations don’t warrant the expense of factory ships with on-board processing and chilling facilities, such as those used by deep-sea fishermen. The question is, how to get the salmon from the pens to the processing plant in the most humane way that preserves the quality of the fish. The answer is a surprisingly old one.

Carrying the salmon and other fish live in tanks aboard ships like floating aquariums isn't a new idea. According to ancient writers like the first-century Roman naturalist Pliny the Elder, and modern archaeology, fish have been carried alive aboard ships for at least two thousand years. Dozens of such ships already operate in the waters around Norway alone, but in recent years the trend has been toward more and larger ships, such as the latest one from Rolls-Royce.

The one being built for Bakkafrost is a Rolls-Royce type NVC 386. It’s 75.8 m (248.6 ft) long, is 16 m (52.4 ft) abeam, and has a carrying capacity of 3,000 cubic meters (105,944 cu-ft). That’s 1/6 larger than an Olympic-size pool and is enough to hold 450 tonnes (442 tons) of live fish in piscatorial comfort. In addition, the ship has a wave-piercing bow that allows to maintain speed and stability in rough seas while using less fuel for the diesel-electric propulsion system with two Bergen C6 engines.

It will operate in the Faroe Islands, where it will transport live Atlantic salmon from Bakkafrost’s pens to on-shore processing factories. Inside the ship are three holds equipped with a closed-circuit pumping system to aerate, filter, and circulate seawater. In addition, there’s a pressurized system to offload the fish as if they were a liquid cargo. There’s even a delousing system to deal with sea lice.

Rolls-Royce says that the new ship has the crew in mind as well with seven single cabins, saloon, dining area, and fitness center with sauna.

"With this design, Bakkafrost will enter into a new era when it comes to quality, capacity, comfort and environmental considerations," says Anders Almestad, Rolls-Royce, President- Offshore. "Extensive development work, including CFD calculations (Computational Fluid Dynamics), has been done to provide the customer with a fuel-efficient and cost-effective vessel."

With one live fish carrier already delivered to Norwegian ship owner Sølvtrans and a second being built, the one for Bakkafrost is Rolls-Royce’s third carrier ship.