HMS Bittern (L07): Sunk at Namsos, Still Leaking Oil Seven Decades Later

A Class Leader Finished Last

HMS Bittern was built by J. Samuel White at Cowes on the Isle of Wight, laid down on 27 August 1936 and launched on 14 July 1937, becoming operational on 15 March 1938.

In a small quirk of naval administration, HMS Bittern gave her name to the entire Bittern class of sloops despite actually being the last of them completed, her sister ships having entered service ahead of her.

At barely 1,190 tons standard displacement and 86 metres in length, she carried three twin 4-inch guns doing double duty against aircraft and surface targets, a pair of 3-pounder Hotchkiss guns, a quadruple half-inch machine gun mount, and depth-charge throwers built for hunting the U-boats she was actually designed to fight. None of it counted for much against a Stuka coming almost straight down.

The sloop was a particular sort of ship and worth understanding, because Bittern belongs to a short, distinguished and rather expensive line. Unlike the Flower class corvettes rushed out of small yards a few years later, these were properly designed warships: good sea boats, well built, and armed with a heavy battery of dual-purpose 4-inch guns on mountings that could actually elevate to track an aircraft. That was unusual for 1937, when a good many navies were still fitting escorts with guns that could not point upwards at all. The trouble was that they took time and money to build, which is why the Navy ended up ordering hundreds of cheap corvettes as well. The design line ran on through the Egret class to the Black Swans, which turned out to be the finest escorts Britain produced in the whole war.

Her two sisters fared rather better. HMS Enchantress, completed first in 1935, was sold out of naval service in 1946, while HMS Stork went on to genuine fame leading Commander Frederic "Johnnie" Walker's celebrated 36th Escort Group and ramming the U-boat U-574 during the battle for convoy HG 76, before finally being broken up in 1958. Bittern, the ship that gave the class its name, was also the first of the three to be lost.

The contrast between the three of them is worth pausing on. Enchantress spent much of her career as an Admiralty yacht and was sold off in 1946. Stork, under Commander Frederic Walker, was in the middle of the action that changed the Atlantic war: over five days in December 1941 the escort of convoy HG 76 destroyed five U-boats, the first time a convoy escort had comprehensively beaten a pack, and Walker went on to become the most successful anti-submarine commander of the war before dying of exhaustion in 1944, aged forty-eight, and being buried at sea from Liverpool. And Bittern, the ship whose name the class carries, was dead within eight months of the war beginning, sunk by aircraft in a Norwegian harbour without ever getting near a submarine.

Into the Namsos Campaign

HMS Bittern spent her early war service in home waters before being deployed to Norway's coast during the 1940 Namsos campaign, part of the ultimately unsuccessful Allied attempt to help Norway resist the German invasion. Her role at Namsos involved defending transport vessels from submarine and air threats, exactly the kind of exposed, dangerous escort work that characterised the entire short, difficult campaign.

The wider operation, codenamed Maurice Force, called for a pincer on German-held Trondheim, with landings at Namsos in the north and Åndalsnes to the south. Without air cover of their own, the troops ashore were pinned down and pounded from above almost from the moment they landed, and within three weeks London had already ordered the whole force home again. Bittern was still on station covering that withdrawal when the Luftwaffe found her.

What happened at Namsos deserves setting out, because it was a shambles from the beginning and everybody involved knew it. Germany invaded Norway on 9 April 1940 and took Trondheim, which controls the centre of the country. A direct assault on Trondheim from the sea was considered and abandoned as too risky, so the Allies landed to the north at Namsos and to the south at Andalsnes and tried to pinch it out instead. The troops went ashore with almost no anti-aircraft artillery, no tanks, no proper transport and, above all, no air cover whatever. The Luftwaffe found them almost immediately. On 20 April the bombers destroyed thirteen hundred and fifty houses in Namsos and left more than eighteen hundred people homeless, and the town, which was built of wood, largely burned. Within three weeks London had accepted the obvious and ordered the whole force out.

The one attempt at air cover is worth telling because of how quickly it failed. On 24 April, eighteen Gloster Gladiators of 263 Squadron flew off HMS Glorious and landed on the frozen surface of Lake Lesjaskog in central Norway, an improvised airfield made of ice. They had almost no ground crew, no fuel bowsers, no proper armourers and nowhere to hide the aircraft. The Heinkels found them at first light the next morning and simply bombed and strafed them where they stood. By the end of 26 April, having shot down two German aircraft, the squadron had no serviceable machines left at all. That was the entire fighter defence of central Norway, and it lasted two days. It is why a sloop lying in Namsos harbour on the morning of 30 April had nothing between her and a diving Ju 87 but her own three twin mountings and whatever her gunners could see.

Dive-Bombed, Then Scuttled by Her Own Side

On 30 April 1940, during intensive Luftwaffe air raids on Namsos harbour, HMS Bittern was attacked by Junkers Ju 87 Stuka dive bombers of I. Gruppe, Sturzkampfgeschwader 1, from around 7am, apparently mistaken from height for a cruiser worth the extra effort. A bomb dropped by Oberleutnant Elmar Schäfer's aircraft struck her stern and set her ablaze; an official War Office photographer, Geoffrey Keating, caught the moment on camera, and a print of the burning sloop survives today in the Imperial War Museum's collection.

Twenty of her crew were killed in the attack, among them Petty Officers Percival Mackenrot and Frederick Sanders and Leading Seaman Harry Ounsworth, all named on the Commonwealth War Graves Commission's roll for that single, brutal morning.

With the fire beyond control, her crew were evacuated by nearby Allied vessels, and HMS Bittern herself was finished off by gunfire from the cruiser HMS Carlisle, a deliberate act of scuttling her own burning, crippled sister-in-arms rather than leave her to sink slowly or fall into enemy hands.

Schäfer, for his part, did rather well out of the morning. On 8 May he was awarded the Knight's Cross of the Iron Cross alongside his Gruppenkommandeur, Paul-Werner Hozzel, among the first Stuka airmen ever to receive one, while Bittern's survivors were still counting their dead.

It is worth following what the failure led to, because the consequences reached a good deal further than Norway. The withdrawal was so plainly a defeat that Parliament turned on the government over it. On 7 and 8 May 1940, in what became known as the Norway Debate, members of Neville Chamberlain's own party rose to tell him he should go; Leo Amery quoted Cromwell at him across the floor, and forty-one Conservatives voted against their own side. Chamberlain resigned on 10 May and Winston Churchill took office the same day, which happened to be the morning the Germans attacked France and the Low Countries. The campaign that killed Bittern and twenty of her people was, within a fortnight, the reason Britain changed prime ministers.

A Wreck That Won't Quite Rest

HMS Bittern's story did not end with her sinking.

By 2011, over seventy years after she went down, her wreck was assessed as still holding an estimated 200,000 litres of oil in her bunkers, a genuine pollution risk rather than an active spill, and a stark reminder that the physical legacy of wartime losses can persist on the seabed for generations, quietly posing new problems long after the war that caused them has passed from living memory.

The general problem is a great deal larger than one sloop. There are thousands of wartime wrecks on the seabeds of the world with fuel still in their bunkers, and steel corrodes at a broadly predictable rate, which means that a great many of them are now reaching the age at which tank walls start to fail. Norway, with a long coastline, a fishing industry and a great many sunken ships from 1940, has taken the problem more seriously than most and runs a national programme to survey the worst of them and empty them. The technique is to fit a valve to the hull first and then drill through it into the tank, so that the oil goes up the hose rather than out into the fjord, and then to pump each tank dry in turn. Bittern's bolt letting go on 1 November 2011 is a reasonable illustration of how fine the margins are.

The Norwegian Coastal Administration, Kystverket, marked the anniversary with a memorial service in Namsos on 13 September 2011, held jointly with the Royal Norwegian Navy, the Royal Navy and the local municipality for the men who died aboard her, before sending divers and the support vessel NSO Crusader to drill into the wreck tank by tank and pump her dry.

The job did not go entirely smoothly. Technical problems with Crusader pushed the schedule back by nearly two weeks that October, and on 1 November a corroded bolt gave way during the works, triggering a fresh leak that forced an emergency pumping operation; around 44 cubic metres of oil were recovered from the affected tank within a day and the leak was stopped. By the time the autumn campaign wound up, contractors working for Kystverket had pumped roughly 80 tonnes of oil clear of the wreck.