Operation Ironclad: the WW2 battle for Madagascar

The early stages of Operation Ironclad were unusual for a British amphibious landing at this stage of WW2 – a complete success. What made the action even more remarkable was that the defenders were not German, Italian or Japanese, but rather French.

In the summer of 1940, when Britain’s top brass considered the implications of the imminent fall of France, they started to pay more and more attention to Madagascar. The French colony’s vital location off the east coast of southern Africa meant that an enemy naval or air presence there could threaten British sea communications. Worse still, with the Mediterranean route becoming increasingly dangerous it could even cut off links with the Middle East, India and the Far East.

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However, with British forces over-stretched at home, in the Atlantic, the Mediterranean and north Africa, there were precious few resources available for overseas expeditions. The military assessed the threat to Madagascar from Germany and Italy as low, and action was confined to sending in a SOE team to gain information.

In fact, Japan was gradually coming to be seen as the greater danger. This concern only increased when the Japanese bullied the Vichy government into handing over bases in Indochina. If the Japanese were to repeat this tactic to seize bases in Madagascar, Britain’s entire strategy could unravel.

The British government therefore began to plan for pre-emptive action against Madagascar. It drew up initial plans in 1940 but then put these on hold, simply because it didn’t regard these as a high priority.

Taking a risk

While Prime Minister Winston Churchill was keen to seize the initiative, the Chiefs of Staff were sceptical that Japan would attempt such a risky operation. Their attitude changed rapidly in the wake of the attack on Pearl Harbor in December 1941, which proved beyond doubt that the Japanese were not averse to bold action. As the Allied position in the Far East deteriorated in the face of Japanese advances, Madagascar’s perceived significance increased and planning stepped up a gear.

There were two complicating factors. First, Britain simply lacked the forces for a major operation, especially given the need to reinforce India. Second, the island’s authorities were loyal to Vichy and there was an understandable reluctance either to kill French soldiers or to provoke the Vichy government into closer co-operation with Germany.

Both considerations made it highly desirable to formulate a plan for a limited-scale operation that would achieve complete surprise. This would ensure swift success, so avoiding a prolonged commitment while minimising French casualties.

The expedition would have the limited aim of taking Diego Suarez on the northern tip of Madagascar, with its superb harbour and airfield. The rest of the huge island could be left to later.

This still presented the British with a problem – namely that the French defences were concentrated at Diego Suarez, with the single, narrow channel that led into the bay heavily protected by gun batteries on high ground. A frontal attack would risk high losses among the British forces as well as the French.

The British planners therefore decided to risk a landing on the less strongly defended western coast. Such an approach would require night-time navigation of waters that the French believed to be impassable in darkness. But it permitted the complete surprise that could allow the British to get safely ashore and then advance a few miles overland to attack the defences in the rear.

Rear Admiral E Neville Syfret commanded a powerful force that included the battleship Ramillies, the aircraft carriers Illustrious and Indomitable (with 86 Fleet Air Arm fighters and strike aircraft), two cruisers, 11 destroyers, six corvettes, six minesweepers and 18 amphibious assault ships and transports. The landing force, under Major General RG Sturges, Royal Marines, included four brigades of troops with artillery and a small force of tanks.

As the assault force landed on the western coast, the cruiser Hermione fired a bombardment off the eastern coast as a diversion. At the same time, Fleet Air Arm aircraft swept in to hit warships and submarines in the harbour and to destroy most of the Vichy air force on the ground, gaining air superiority from the outset.

By 6.30am, all of the beaches had been taken and some 2,300 troops had been landed. The advance across difficult terrain in tropical heat initially encountered limited resistance but this began to stiffen, until the British forces were held up by a formidable defensive line of forts, gun positions and trenches about three miles short of the town.

Attacks on these positions on the first and second day of the operation failed to break through due to the shortage of artillery and armour.

A prolonged commitment, the worst fear in London, seemed inevitable. However, General Sturges now played his master stroke. He planned a night attack, to confuse the defenders, while also dislocating them with another amphibious landing into the town behind them from an ‘expendable destroyer’.

Two hours after sunset, HMS Anthony ran the gauntlet of the French gun batteries to land a party of 50 Royal Marines. Their mission was to create a diversion “to take the Frenchmen’s eye off the ball”, and they went about it with commendable enthusiasm. In the words of Admiral Syfret, they “effected disturbance out of all proportion to their actual numbers”.

At the Marines’ signal, two army brigades launched their own assault, and the French defenders, under attack in the dark from the front and the rear, capitulated. The following morning naval gunfire brought about the surrender of the remaining French positions, and Diego Suarez was secured.

Britain lost 105 killed and 283 wounded; one minesweeper was sunk and seven aircraft destroyed. The French lost 150 killed and about 500 wounded, as well as three submarines, 17 aircraft and two corvettes. The British warships returned to their usual stations, while the landing forces moved on, to reinforce India (they were replaced at Diego Suarez by forces brought in from Africa). The rest of the island was taken later in 1942 in Operation Stream-Line-Jane.

Operation Ironclad was a small-scale expedition against an opponent with limited capabilities – and not everything had gone well. However, as a complicated operation launched against a target 9,000 miles from Britain, there’s no doubting it was ambitious. Above all, its complete success at such low cost proved an important step. As one of the brigade commanders put it, Ironclad was “the first cheerful bit of news that the British had had for a long time, the first amphibious operation of the war where we had landed and stayed put, the first properly concerted campaign, however miniature”.

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The expedition demonstrated that Britain was still capable of exploiting her sea power to take the initiative. It showed that Britain’s ability to conduct amphibious operations had come a long way.

The plan was innovative and well conceived, using a night landing and an unexpected direction of attack to achieve complete surprise. This surprise was then effectively exploited with air strikes to knock out the defending air forces and with a rapid advance.

When the initial attack ground to a halt, the British unlocked the enemy position by a brilliant improvisation. Carrier-based aircraft proved their ability to support landings out of the range of air bases. Well-trained amphibious forces showed their utility, as did specialised amphibious shipping, including the first prototype of the tank landing ship.

The lessons of the campaign accelerated some programmes that were already under way, such as building dedicated amphibious flagships. It launched some new ones, such as creating the Beach Commandos to manage troops and supplies after landing.

The British also identified important lessons about co-operation between naval and land forces, especially the provision of air support from aircraft carriers. These became vital in the November 1942 landings in north Africa, the 1943 landings in Sicily and Italy, and the assault on fortress Europe in 1944.

So, not only was Ironclad a success in its own right, it also paved the way for later victories.

Dr Tim Benbow is a senior lecturer in Defence Studies at King’s College London, based at the UK Defence Academy

This article was first published in the September 2012 issue of BBC History Magazine