“This will take great skill and concentration for long periods in very challenging conditions – so any analysis we can undertake early will provide comfort that the replenishment at sea capability can be met with the new ships.

Commodore David Preston, Head of RFA Engineering.

Two 1:44 scale models – the 37,000-tonne 200m-long (659ft) tanker has been reduced to 4.5m (15ft) in length, while the 65,000-tonne HMS Queen Elizabeth has been shrunk from 284m (931ft) in length to 6.45m (21ft) – were built and taken to the enormous ‘ocean basin’ test tank, owned by defence research firm QinetiQ.

The tank in Haslar, Gosport, is 122m (400ft) long, 61m (200ft) wide and 5.5m (18ft) deep – over 15 times more water than in a typical Olympic-sized swimming pool – and can simulate both calm and rougher seas.

Whilst the tank is regularly used by the maritime community, this is the first time that two new ships have been tested for RAS operations.

“The RFA ships will have to keep station using the Queen Elizabeth-class as a guide during RAS,” explained Cdre David Preston, head of RFA Engineering.

“This will take great skill and concentration for long periods in very challenging conditions – so any analysis we can undertake early will provide comfort that the replenishment at sea capability can be met with the new ships.”

Tests in the Haslar tank were carried out in up to a simulated Sea State 6 – very rough seas, with waves up to 4m or 13ft high – and the two models also practised emergency breakaways and engine failures.

Once all the data has been gathered and analysed it will be used by the RN and RFA to draw up the guidelines for safe operations when Tidespring joins the Fleet in 2016.

Images and video courtesy of QinetiQ.