The Cockleshell Heroes

Photograph from the Movie

Operation Frankton is an operation led by ten men from a small unit of British commandos, the Special Boat Service of the Royal Marines, attached to Combined Operations. The raid, which begins on December 7, 1942, with the launch of five kayaks off the Gironde estuary, is aimed at attacking blockade forceors, Axis ships, based in the Port of Bordeaux providing connections with Japan. The operation will be a success but eight of the ten commandos will lose their lives, drowned or executed by the Germans.

The plan

The plan consists, in short, that an officer and eleven other men of the Royal Marines go up the Gironde in small canoes, circulating only during the night, and place mines limpets (sticks of magnetised explosives) under the line Of the vessels they will find in the port of Bordeaux. The canoes will be brought up to some nine miles (16 km) from the mouth of the Gironde into a submarine performing its normal patrol service and will not need to be specially designed.

The mission

On the evening of December 7, 1942, the British submarine HMS Tuna put five kayaks in the water (Catfish, Coalfish, Crayfish, Cuttlefish and Conger) with ten crewmen off Montalivet-Soulac Gironde). A planned sixth kayak (Cachalot) having been torn during the launch, the crew (William Ellery and Eric Fisher) returned to England aboard the submarine. The members of the commando were to ascend the estuary by hiding during the day, to lay mines on the ships they would find, and to abandon their canoes arrived at Bordeaux. One of the five kayaks (Conger) disappears while passing the eddies of the mouth. The Cuttlefish is lost sight of. The three canoes (Catfish, Crayfish and Coalfish) can only sail at night and with a favourable tide. They must spend the day hidden in the bushes of the bank. Sergeant Wallace and Marine Ewart of the Coalfish were captured at dawn near the Point de Grave lighthouse where they had arrived.

At the end of the second night (8/9 December), the Catfish and the Crayfish, continuing their raid, were carried by the tide near the Verdon and forced to slip between the mole and four enemy ships at anchor. On the night of 11 December 1942, around 9 pm, the two kayaks were preparing to complete the final phase of their mission. The Catfish headed towards the quays of the left bank of the port of Bordeaux and managed to fix magnetic mines on three large moored ships. The Crayfish remains on Bassens and lays its mines on two ships moored in the mole. The mission accomplished, the four men have only a few hours to escape from the region. The explosions began six hours later, on December 12, 1942, starting at 7 am.

The withdrawal :

The other group (Hasler and Sparks), assisted by the French Resistance and then by the Catalan and Spanish Republican networks, joined Gibraltar on 1 April 1943, passing through Blaye, Donac, Saint Germain de Vibrac, Saint Even the Carrières, Preuil, Ruffec (18 December 1942), Bois de Benest, Marvaux (where they remain hidden for 42 days), Roumazières, Limoges, Lyon, Marseille, Perpignan, Bañolas, Barcelona, ​​Madrid and finally Gibraltar.

Assessment of the operation:

The mines exploded, four cargo ships, Tannenfels, Dresden, Alabama and Portland, are severely damaged. A sperrbrecher and tanker Cap Hadid are also affected. French firefighters under the authority of engineer Raymond Brard, alias Colonel Raymond of the Triangle-Phidias Network, were immediately summoned, and according to a French report, they deliberately contributed to aggravate the damage by flooding ships with Their lances in order to make them capsize.

Major ‘Blondie’ Haslar and Captain Stewart in a Cockle Mark 2 canoe c.1943, a canoe of the same type used in the raid on Bordeaux in December 1942

Operation Frankton is popularly best known through Jose Ferrer’s 1955 film, Cockleshell Heroes. This itself is to be part of the museum’s celebration, later on, of the 70th anniversary of a covert mission  in Bordeaux on 30th November 1942. It was an operation said by Winston Churchill to have shortened the second World War by six months. It  cost the lives of eight of the ten Royal Marines who took part in it.

The unit in question was the Royal Marines Boom Patrol Detachment (RMBPD), formed on 6th July 1942 based at Southsea, Portsmouth and, almost literally, dead in the water in under five months.

However, the operation scored what is reckoned to be one of the standout achievements of Combined Operations in the war.

Combined Operations training was, of course, pioneered in Argyll, at a variety of bases, many in Cowal, others in Bute and Mid Argyll. Castle House Museum has a list with map locations.

Working up in Portsmouth, Operation Frankton finalised its preparations on the Holy Loch and set sail from there to south west France. It is said that the men did not know they were on a live operation until they were st sea – or in this case, below it, in the T-class submarine that transported them.

So what was the purpose of Operation Frankton; and why the need for the flimsy, collapsible plywood and canvas canoes?  The Ferrer film immortalised these as ‘cockleshells’, borrowing the name ‘cockle’ given to the second generation design of the canoes which was selected for the raid.

Bordeaux, on the Bay of Biscay in German occupied France, was the main port delivering supplies to the German war campaign. Churchill wanted a raid on that shipping to slow up the German advance.

The plan – plans always sound so seductively straightforward – was for six low profile canoes to be released into the Gironde estuary, to paddle their way to Bordeaux, attack cargo shipping with limpet mines and escape overland to Spain in the south.

Thirteen men were chosen for the RMBPD unit – six crews of two and one reserve.

The ‘cockleshells’

The ‘cockle’ canoes had flat bottoms for easier grounding and had to be no more than 28 inches at their widest point – so that they could be passed out of a submarine hatch.

They had five collapsible bracing struts – one at each of the bow and stern, accessed by a hatch; one behind the rear paddler, one in front of the fore paddler and one between the two.

The paddles could be unitary or unscrewed into single short paddles for low profile movement while under possible detection. In these circumstances the paddlers leaned forwards along the canoe to flatten their profile and maximise their camouflage.

They canoes were so low to the water that they were not easily detectable. During the raid in Bordeaux a sentry on a fast patrol boat, Sperrbrecher (to which they had already attached a limpet mine), though he heard something and is said to have shone his torch on a canoe – without seeing it.

They used aircraft compasses which proved more reliable than marine ones.

The limpet mines

Alongside a ship to be attacked – each canoe carried eight limpet mines – the rear paddler had a ‘holdfast’ magnet to keep the canoe tight in to the hull of the ship while the fore paddler planted the limpet mines. Because the resistance of water magnifies the impact of an explosion, it was important to plant the mines well down the hull, below the water line.

A ‘placing rod’ was used to do this, pulled open and foldable with its sections snapping back into full length by the spring of the taut cable that held them together. The lower end of the placing rod had a ‘key’ for the limpet mine to be slid on to; and the top of it was bent into a rudimentary handle to give the mine planter some leverage to attach the mine.

The fore paddler would hang the mine on the placing rod, lower the rod down, move it in to the ship’s hull and lever it in from above to let its six magnets clamp on. The magnet fixings had some mobility to allow for the fact that ship’s hulls are not often level but pitted with damage and barnacles.

With any sea running and even in flat calm, this method of planting the limpet mines must have been fraught with imprecision. The diameter of the placing rods was quite slender.

Part of the kit the raiders carried in their canoes was a spanner – to tighten a wing nut at the top of the mine’s fuse section. Tightened down, this fractured a glass ampoule of acid, which then dripped down onto a metal bar below, separating it from the plastic explosive in the body of the mine.

When all the acid had dripped down and the metal bar dissolved, the acid would hit the explosive and it was fireworks time. There were strategic time-to-bang choices to be made in the strength of the acid ampoule chosen. Theoretically at least, some could take weeks to eat through the metal.

Interestingly, early limpet mines in testing used aniseed balls to block the passage of the acid to the explosive – and it happened that the dissolve rate of the aniseed balls was the same as that of the metal bar used in the production models. Now we know why so many of us broke teeth on aniseed balls in careless youth.

The other Argyll connections

The Commanding Officer of the RMBPD unit, Major Herbert ‘Blondie’ Hasler was, as the originator of the concept, one of the marines on the raid. One of the two of the ten who set off on it to survive and escape, he later retired to farm in Tayvallich and died in 1987.

Lieutenant Jacky Mackinnon, from Oban, was one of the six on the raid who was captured and executed by the German.

There was a second Scot on the raid – Marine Robert ‘Bobby’ Ewart from Scone in Perthshire, whose family moved to Glasgow from where he  joined up. Ewart too was captured and executed.

Ewart’s is a particularly poignant story, with the exhibition showing a copy of the letter he left for his 15 year old girlfriend – the daughter of his landlady in Portsmouth.

Servicemen traditionally leave letters for loved ones, to be opened should they not return from operations. Ewart didn’t, of course.

He celebrated his 21st birthday on board HMS Tuna and en route to France to commence the mission. His girlfriend, died from TB just before her 17th birthday – though some say it was a broken heart.

The letter he left is mature, philosophical, objective and loving – a remarkable and very moving piece of writing.

The raid

Six ‘cockle’ canoes – Catfish, Crayfish Coalfish, Cuttlefish, Conger and Cachalot, with their 12 crews and the reserve, left the Holy Loch on 30th November 1942 in the belly of the submarine, HMS – Tuna (left). Oh yes.

Weather delayed progress but, only a day late, on 7th December and ten miles or so off the entrance to the Gironde, five of the six canoes slid in to the sea and paddled off. Only two of the ten crew would live. The sixth canoe – Cachalot – got damaged in coming through the submarine hatch so her crew did not go on the mission. And the reserve was not required.

It’s easy to fail to build in to the ‘Cockleshell Heroes’ story the sheer physical nature of this raid. It happened in winter, when air and water temperatures were low and sea conditions often dangerous – this was in the notorious Bay of Biscay. They paddled at night, when temperatures were even lower, taking five minutes rest every hour; and pulling in to the reeds at the shores of the marshy Gironde to conceal their presence during the day.

On the first night as the canoes approached the mouth of the River Gironde, they hit a violent rip tide. The waves were five feet high and the canoe ‘Conger’ was lost. The two crew of ‘Conger’ – Corporal George Sheard and Marine David Moffat – were towed by the other canoes. Once near the shoreline, both men had to swim to the shore as they were slowing down the remaining canoes. Neither man made it to the shore. It was later established that her crew did not drown but died in the water of hypothermia.

The crew of the canoe ‘Coalfish’ – Sergeant Samuel Wallace and Marine Robert Ewart – were caught by the Germans, interrogated and shot after being held captive for two days. Despite being in uniform, their captors carried out Hitlers infamous ‘ Commando Order ‘ – that anyone captured on commando raids was to be shot.

The crew of the ‘Cuttlefish’ – Lieutenant John Mackinnon and Marine James Conway – had to abandon their canoe after it was damaged. They were also caught by the Germans who handed the pair over to the Gestapo. It is thought that both men were held and interrogated for about three months before being shot.

The crews of the two canoes that made it to carry out the raid on the night of 11/12 December – Catfish and Crayfish – had paddled a total of around 90 miles in four days before reaching the docks at Bordeaux.

While the plan to get them there was detailed, there was no information on what ships would be in the harbour for them to mine. They were going to have to busk that on arrival. In the end, with only these two canoes left to do the job,  Hasler and his number two, Marine Sparks, in Catfish took the west side, with Corporal Laver and Marine Mills in Crayfish taking the east side – both doing whatever they could with what they found and starting at around 21.00.

Catfish planted all eight of her limpets on four ships. Crayfish – unable to find any shipping on the east docks, went to shipping moored in the South Basin and planted all eight as well, five on a large cargo ship and three on another smaller ship.

As they left the river, the two canoes happened to meet up in a little island in the estuary, paddling on in company until they got to shore where they sank their canoes and split.

Two days later, Laver and Mills were caught and were executed. CO Hasler and Sparks had to hide up for over a couple of weeks at one point and were then led across the Pyrenees by the French Resistance. Hasler got on to an aircraft in Gibraltar and was home on 2nd April 1943, days over four months after leaving the Holy Loch on HMS Tuna. Sparks got back as well – but by sea, a longer passage.

After the raid

Research later revealed that six ships has been damaged in the raid. Five were back in service quite quickly. One was extensively damaged – was this the big cargo ship that got five of Crayfish’s limpet mines?

In November 2011, a BBC Timewatch television programme presented by former Liberal Leader, Paddy Ashdown who was an officer in the SBS (Special Boat Service),  suggested there may have been a classic British foul up.

It was stated that a second and simultaneous operation, aimed at sinking ships in Bordeaux docks was led by the SOE (Special Operations Executive) and that Claude de Baissac, leader of the SOE cell active in that area, was actually preparing to take explosives on to ships when he heard the Cockleshells’ limpet mines going off.

Although there is evidence to support the SOE being in the Bordeaux area prior to the Frankton Raid and that the docks were of strategic interest to them, many would still argue that there is no direct evidence to suggest they were planning any attack at the same time as the Cockleshell Heroes.

In any case, Hasler and Combined Operations would have known nothing about this parallel operation if there was one, for SOE traditionally told no one of their operations.

While Churchill and Lord Louis Mountbatten, who commanded Combined Operations, made much of the success of Operation Frankton, it may be hard to agree.

Although, the heroism of the men in the forbidding and physically demanding circumstances of this raid is awe inspiring, the heavy cost in lives does not quite square with the limited damage two canoes made at the docks.


Endlessly inventive and a longtime sailor, Hasler went on to invent self-steering gear – or autopilot – for yachts. This revolutionised single-handed sailing and Hasler was the man responsible for the Observer Single-Handed Transatlantic Race. In 1980 he took part in the first of these, in Jester – a customised Folkboat (have you seen how small these lovely wooden boats are?). Jester was the only one of the five competing yachts to be fitted with Hasler’s self-steering device. She did the passage in 48 days, finishing second to Francis Chichester’s much bigger Gypsy Moth III.

Hasler had been awarded the Distinguished Service Order and Sparks the Distinguished Service Medal for Operation Frankton. Laver and Mills, who perished first when Conger was overwhelmed by the seas on the first might, were mentioned in dispatches. They had been recommended for the DSM but at that tine this medal could not be awarded posthumously.

On 12th November 2010, the Provost of Glasgow City Council, Bob Winter, entertained to tea the sister of Lieutenant Jacky Mackinnon, Isabella Mackinnon and her niece and nephew. This was a commemoration of the service in Operation Frankton of the Oban born marine whose family had, like that of the other Scot in the raid, Bobby Ewart, moved to Glasgow.

The Frankton Trail

In south west France, in June 2002, the Frankton Trail was opened and has since been developed with information boards en route.

This is a long distance walking trail tracing Hasler’s and Sparks’ 100 mile route to safety  through occupied France. The walk has been created by the  Frankton Souvenir, an Anglo-French organisation dedicated to keeping the story of this unique raid alive.