Operation Frankton: The True Story of the Cockleshell Heroes

Did you know the famous war movie The Cockleshell Heroes was based on a true story? Discover the real story of Operation Frankton here.

Was “The Cockleshell Heroes” real?

Image: 1955 poster for the Cockleshell Heroes (Public domain)

For many a war film enthusiast, the 1955 men-on-a-mission movie The Cockleshell Heroes holds a special place in their heart.

Directed by and starring José Ferrar, alongside Sir Christopher Lee and Trevor Howard, The Cockleshell Heroes was a critical and domestic commercial smash on release.

Released in November 1955, The Cockleshell Heroes topped the UK box office. It was one of the top ten most popular films at the British box office in 1956. However, like most British war films of the time, it flopped at the UK box office.

Its failure in the United States has not blunted enthusiasm for the film at home. 

The Cockleshell Heroes is one of the more rousing British war movies of the 1950s.

Royal Marine Major Stringer is called on to form a crack squad of incorrigible British Marine volunteers for a highly dangerous mission: the deployment of a small kayak-borne troop to sail upriver and sabotage an entire German shipyard in Nazi-occupied France.

It’s the kind of story that a certain generation of British and Commonwealth boys and young men were raised on: determined soldiers heading out on a potential suicide mission in enemy territory for the sake of duty.

But did you know it is based on a true story?

Operation Frankton was the codename given to the real action undertaken by Britain’s Cockleshell Heroes during the Second World War.

What was Operation Frankton?

"Of the many brave and dashing raids carried out by the men of Combined Operations Command, none was more courageous or imaginative than Operation Frankton." – Lord Louis Mountbatten

Operation Frankton was the codename given to the Royal Marine-led raid on Bordeaux, France between 7-12 December 1942.

Bordeaux was a major seaport under German occupation during the Second World War. Many raw materials essential to the Nazi war effort, such as rubber and animal and vegetable oils, passed through Bordeaux. 

Ships leaving Bordeaux were often bound for German-held ports in the Soviet Union where the German armed forces were attempting to wage a war of extermination on the Soviets. Any efforts to sabotage them would be greatly appreciated by the Western Allies’ Soviet partners.

Because of its strategic importance, Bordeaux was heavily defended. The port was bristling with coastal defence guns, anti-aircraft batteries and no less than 32 Kriegsmarine vessels patrolling the waters nearby.

A direct assault on the port would prove incredibly costly and no guarantee.

Instead, a more subtle approach was suggested. 

Devised by Major Herbert “Blondie” Hasler, Operation Frankton called for 34 men deployed by submarine off the French coast. 

The Royal Marines would then paddle 60 miles up the Gironde Industry in kayaks, attach limpet mines to the cargo ships at the harbour, and then escape overland to Spain.

Permission for the raid was granted by Chief of Combined Operations Lord Louis Mountbatten in October 1942.

Where does the name Cockleshell Heroes come from?

Image: A Mark II "Cockle" kayak from which the Cockleshell Heroes got their nickname (IWM (MAR 583))

While Major Hasler hated the term “Cockleshell Heroes”, the name comes from the small folding kayaks the Royal Marines used in Operation Frankton.

The Mark II Kayak’s codename was codenamed “Cockle”. With a plywood deck and hull bottom, but canvas sides, the Mark IIs were foldable, making them easy to stow in the confined spaces, like a cramped submarine interior.

Crucially, the kayaks had enough room for all the equipment needed by the Royal Marines for Frankton, including eight limpet mines per boat. Otherwise, the Marines were lightly armed with pistols, hand grenades, and a combat knife.

Who were the Men of Operation Frankton?

Image: The men of Operation Frankton

Operation Frankton’s commanding officer was Major Herbert “Blondie” Hasler. Growing up in Portsmouth, Herbert was at home on the water. He had built his own canoe as a boy and regularly rowed from Portsmouth to the Isle of Wight.

Upon leaving school, Herbert was commissioned in the Royal Marines. Creative, highly intelligent, but also private and insular, Major Hasler was a complex character but a consummate professional. He had earned an OBE for his work in the ill-fated Norway Campaign in 1940.

His nickname, “Blondie” came from his magnificent blonde moustache.

Herbert’s second-in-command on Operation Frankton was Captain J.D. Stewart.

Altogether, 13 men were chosen for Operation Frankton, including Major Hasler and Captain Stewart, split into two teams of six canoes.

A Division

• Major Hasler & Marine Bill Sparks in kayak Catfish
• Corporal Albert Laver & Marine William Mills in kayak Crayfish
• Corporal George Sheard & Marine David Moffat in kayak Conger 

B Division

• Lieutenant John Mackinnon & Marine James Conway in kayak Cuttlefish
• Sergeant Samuel Wallace and Marine Robert Ewart in kayak Coalfish
• Marine W.A. Ellery and Marine E. Fisher in kayak Cachalot

Marine Norman Colley was taken as a reserve.

Operation Frankton: Kayaking upstream

Image: Blondie Hasler, front, with a Royal Marine kayaking prior to Operation Frankton (© Trustees of the National Museum of the Royal Navy)

The Marines left Holy Loch naval base, Scotland, aboard the submarine HMS Tuna on November 30, 1942.

After a week at sea, the sub breached and dropped off her passengers at the Gironde Estuary mouth on the night of 7/8 December. The water was rough and choppy, with some waves crashing in at over 5 metres in height. 

Unfurling their canvas boats on deck, the Marines took to the water. Cachalot was damaged bringing it out of the submarine’s hold, so Marines Ellery and Fisher remained on Tuna with Norman Colley.

The successfully launched kayaks now began the perilous sixty-mile paddle upstream into enemy territory.

The five remaining kayaks carried on. Conger capsized on the first day, causing Marines Sheard and Moffat to swim to shore. 

The force came across a checkpoint, manned by Wehrmacht soldiers and supported by three Kriegsmarine frigates. Detection would have been disastrous for the small raiding party. To avoid detection, the Marines lay flat in their boats, paddling silently passed German patrolmen.

On the first day of Operation Frankton, the kayakers had covered 20 miles, roughly a third of their journey. Only Catfish, Coalfish, and Crayfish remained.

The Marines came ashore at St. Vivian du Medoc where they hid for the night. Unbeknownst to Crayfish and Catfish, Sergeant Wallace and Marine Ewart manning Coalfish were captured at daybreak near the Pointe de Garve lighthouse as they came ashore. 

Two kayaks now remained. Across the next two nights, the Marines covered around 40 miles, bringing them close to Bordeaux. On the night of the 10/11, their progress was impeded by strong ebb flows, covering only 9 miles.

The original operation plan called for the bombs to be deployed on 10 December. However, the river conditions caused Major Hasler to change his thinking. Instead, the Marines would spend a day hiding and resting before setting off on the night of 11/12 December.

Operation Frankton: Destination Bordeaux 

On the night of December 11, the two remaining kayaks sleekly took to the water and set off for Bordeaux.

At 09.00 pm, the attack began. The small boats had managed to enter Bordeaux undetected, slipping by watchmen and vessels under cover of inky darkness.

Catfish, crewed by Major Hasler and Marine Sparks, placed eight limpet mines on a German patrol boat. 

It’s reported that a sentry aboard the boat spotted some shadows on the water and shone his light down to investigate. Fortunately, the camouflaged kayak wasn’t spotted and so Catfish slipped away.

By 00:45 pm, Catfish had finished planting its mines on cargo vessels and headed back towards the sea. 

At the same time, Corporal Laver and Marine Mills in Crayfish had reached the eastern side of Bordeaux Harbour, but, finding no targets, headed to ships docked at nearby Bessens. 

There, the pair attacked eight limpet mines on two vessels: five on a large cargo ship and the remainder on a small ocean liner.

Operation Frankton: Escape & Capture

Image: Map showing the route taken by kayaks Crayfish and Catfish during Operation Frankton

Sailing downriver towards the Atlantic Ocean, Crayfish and Catfish met by chance at Ile Cazeau. The two kayaks travelled together until 06.00 am when they came ashore at St Genes de Blaye. 

After scuttling their kayaks, the two crews wished each other good luck and set off separately for Spain.

The trip to Spain would be long and arduous. As part of the planning, the Marines had been ordered to head for the town of Ruffec, around 100 miles from Bordeaux, and link up with French resistance fighters.

In the south of France, the Resistance was operating what were called “escape lines”, helping Allied servicemen cross the Pyrenees into neutral Spain.

Two days into their journey, Marines Laver and Mills were apprehended at Montileu-la-Garde by French Gendarmes. Betrayed, the Marines were handed over to German authorities.

Meanwhile, Major Hasler and Marine Sparks arrived in Ruffec on 18 December. There, they linked with resistance leader Mary Lindell and her son Maurice. 

A remarkable woman, Mary Lindell had been a frontline nurse in the First World War and spent the Second World War running escape lines in the south of France.

Taken to a local farm, the Royal Marines hid for 18 days until, finally, they were guided by foot over the mountains into the comparative safety of Spain.

It was not until April 1943 that Hasler arrived safely back in the UK, leaving Spain via Gibraltar.

Hasler was flown back but Sparks was sent by sea and arrived back in the UK.

Operation Frankton: Aftermath

Chaos reigned in Bordeaux and Bassen harbour following the first explosions. 

Six ships were damaged thanks to Operation Frankton – four experienced severe damage.

The freighter Dresden had its superstructure and propeller shaft severed and sunk to the bottom of Bordeaux harbour. Alabama, another cargo ship, was holed by blasts from five limpet mines. 

Elsewhere, Portland suffered severe internal fire damage while the German blockade runner Tannenfels listed heavily and sank. No longer seaworthy, she was later raised and used as a blockship in the Gironde.

German dictator Adolf Hitler was reportedly furious that “this child’s boat” could have evaded German defences.

Was Operation Frankton a success?

The mission itself was a success, completing its objectives, but the military effectiveness of Operation Frankton has been called into question by contemporary historians.

Many of the damaged ships were repaired and brought back into service. The impact Frankton had on the German war machine’s Eastern Front trade was negligible.

What’s more, it has been revealed that the Special Operations Executive (SOE) had been planning an attack on Bordeaux Harbour. The SOE mission, which had the potential to lower the operation's the human cost, was aborted following Frankton.

This showed that, even three years into the war, certain departments of the British military were struggling to coordinate effectively.

Despite the military impact of Operation Frankton, what cannot be debated is the sheer courage and bravery of the Royal Marines who volunteered for this intensely dangerous mission. 

Regardless of the outcome, these men put their lives at risk for a mission they truly believed in with ten of the twelve volunteers paying the ultimate price for their involvement in Operation Frankton.

Did any of the Cockleshell Heroes survive?

Sadly, only Major Hasler and Marine Sparks were the only survivors of Operation Frankton. 

At this stage of the Second World War, Hitler had issued his infamous “Commando Order”. This essentially meant that Commandos and Special Forces soldiers were to be executed without trial, even if attempting to surrender or in military uniform.

This was the fate of Mills, Laver, Wallace, Ewart, Mackinnon, and Conway. The Royal Marines were caught by German patrols or betrayed by locals, resulting in their executions.

Corporal George Sheard and Marine David Moffat were not captured but the pair succumbed to hypothermia after being plunged into the Gironde Estuary's frigid waters.

Commemorating the real Cockleshell Heroes

Image: Plymouth Naval Memorial

With no known graves, the dead of Operation Frankton are today commemorated by the Commonwealth War Graves Commission’s naval memorials at Plymouth and Portsmouth.

These memorials commemorate Royal Navy personnel lost during the two World Wars. 

As Navy casualties were often committed to the deep, they had no known war graves and resting places, and so these memorials provided a permanent point of commemoration for these lost souls.

Conway, Ewart, Laver, Mills, Moffat, Sheard and Wallace are together commemorated on the Second World War extension of Plymouth Naval Memorial.

Mackinnon is commemorated on the Portsmouth Naval Memorial.