WHEN the military hospital ship Argus sails back home on Tuesday from West Africa, the Scots troops on board will be hailed as heroes for their role helping fight Ebola ...

but the one thing that kept them going, they all say, is Irn Bru - even though the national drink was so coveted that a single can traded for £10 between members of the rescue team.

For the six months that RFA Argus has been away, Scots troops on board have been helping save isolated island communities from hunger, developing a pioneering blood donation project - and working out how to get their hands on precious cans of Irn Bru.

The ship has been anchored off the coast of Sierra Leone since October, providing a base for Royal Marines and Naval helicopters distributing aid as well as a fully-equipped hospital on board for any injured military personnel.

Sierra Leone has been one of the countries worst affected by the Ebola crisis, which is now believed to be easing. Despite the grim setting, Scots attached to the rescue mission have been trying to maintain memories of home, with little treats like their favourite soft drink - even though Irn Bru was so rare is was changing hands for £10 a can.

Medics on board - including Scots Warrant Officer Jim Robinson - were involved in setting up a pioneering project which filters platelets from blood donations from troops to help Ebola victims.

Blood is taken from volunteers among the ship's personnel, which is then separated so that the platelets - which are essential for blood clotting and help prevent uncontrolled bleeding - can be removed. The rest of the blood is then given back to the donor, while the platelets can be flown to be used in the treatment of victims of Ebola.

It is the first time blood products have ever been donated on an operational Royal Navy service ship and helps to overcome the difficulty in flying supplies of platelets - which only last a few days - in from the UK.

Among the missions the crew of RFA Argus carried out has included delivering tonnes of food to help islanders who were cut off from their usual trading activities with the mainland of Sierra Leone due to the deadly Ebola virus. The three-day mission in December involved providing food to more than 16,000 people in the Turtle Islands and neighbouring Sherbro Island, 60 miles south of the capital Freetown.

Helicopter crews based on RFA Argus also carried the country's President Ernest Bai Koroma to remote towns to allow him to spread messages about combating Ebola.

The efforts of RFA Argus were recognised last month, when Defence Secretary Michael Fallon awarded the ship a rare Admiralty Board Letter of Commendation - which was last given out in 1939.