Nothing in military history was more dangerous, courageous and excruciating than the Arctic convoys of World War II.

Winston Churchill called them “the worst journey in the world”, and all those involved were tested to the limits of human endurance and beyond.

Yet not until this week, more than 70 years on, was their heroism officially recognised when 41 survivors of that unique exercise, all in their late 80s and 90s, went to 10 Downing Street to receive the new Arctic Star medal from Prime Minister David Cameron.

Among the first to be invested was Derek Hirst, of Blenheim Gardens, Kingston, who joined the convoys in December 1944 as an 18-year-old midshipman on board the destroyer, HMS Zambesi.

The convoys, which operated from 1941 to 1945, braved attacks from enemy aircraft, submarines and battleships to get vital supplies of food and ammunition to Russian ports of Normansk and Archangel, thus enabling the Soviet Union to continue supporting the Allies following its invasion by German forces.

The danger of enemy action from air, land and sea was lethal.

Equally dire was the weather as the merchant ships and their armed naval escorts followed a route edging the Arctic Circle in a bid to keep beyond reach of attack.

They had to contend with ice floes; gigantic waves of 30 feet or more, that tore at the ships’ armour plating, and could sweep decks clear of everything and everyone; sub-zero temperatures that froze hair and took the skin off ungloved hands; and Arctic gales that could scatter a convoy and make it hard to re-assemble.

There was none of the protective clothing that is the norm today.

As Derek Hirst recalls: “We simply had duffle coats, balaclavas our mothers knitted for us, woolly hats and seaboot stockings.”

However, the weather could sometimes be a blessing.

He said: “Our journeys were about 1,200 miles each way and went up the side of Norway, which left us vulnerable to air attack from at least three bases. This meant that when the weather was OK for flying there used to be about 50 JU88s torpedo bombers coming for us – instances when we were glad of bad weather.”

He described how U boats mainly attacked at the northern end of Norway, as the convoys approached Kola Inlet at the entrance of the river up to the port of Murmansk.

He said: “On one of the four convoys I was on we lost three escort vessels and four merchant ships. It was well known that if you went into the water you had less than five minutes to survive.”

One of the escorts lost that day was Bluebell. Derek saw it explode, killing all 95 men on board including one of his schoolmates.

In all, 78 convoys delivered 4m tons of cargo. But the price was the loss of more than 3,000 seamen – most in their teens and 20s – plus 104 merchant ships and 16 military ones.

And of the estimated 66,500 men who took part, only a few hundred are alive today.

Derek was probably speaking for all his fellow survivors when he said that, on hearing they were to receive a medal, his first thought was of those “who would not have the pride of receiving it because it was 70 years too late, and also of those 3,000 who have an Arctic grave.”

Derek particularly remembers February 14, 1945, when HMS Zambesi led a four-destroyer task force 60 miles behind enemy lines to rescue 525 Norwegians from Soroy Island.

He said: “The Germans had begun to withdraw from northern Norway and ordered the people to leave their homes and move south.

To make sure they obeyed, the Germans burned down every house on Soroy, killing animals and destroying food stocks.

“They took away the fittest 1,200 islanders for forced labour, leaving those who could to flee to the hills. The men hunted reindeer and caught fish at the risk of their lives, for the Germans often returned with patrols and picked up whoever they found.”

The rescue force, with all guns manned, reached the island undetected by enemy armed trawlers close by. At a pre-arranged signal, the Norwegian fugitives left their caves and came skiing down to the beach.

Derek said: “It took us nearly three hours to get them all aboard our destroyers. Then came the most difficult part of the operation: to get them safely to Britain.”

The rescue fleet reached Murmansk soon after dawn and the patriots were put on board merchant ships for England. One of these, the Henry Bacon, was torpedoed and sunk, whereupon the refugees were put in the only serviceable lifeboats while the crew took their chances in the open raft.

The Zambesi and the Zest were sent to find them.

Derek said: “We managed to pick up the Norwegians, but most of the crew in the open rafts were dead.”

Derek, who has lived in Kingston for the past 32 years, left the navy in 1946 and, after a spell on a North Sea trawler, followed his father into the laundry industry, eventually becoming a director of the biggest laundry in Europe, Sunlight.