Why This ‘Ridiculous’ British Biplane Crippled The Most Powerful Battleship Ever Built

May 1941, the North Atlantic, a 50,300 ton battleship, the most powerful warship in European waters, had just destroyed HMS Hood in under 3 minutes.

1415 men dead.

Only three survivors.

The Royal Navy mobilized every available ship to hunt the Bismar.

But by May 25, the battleship vanished.

31 hours of nothing, no radar contact, no visual sighting.

Britain’s most dangerous enemy was slipping toward the safety of French ports and Luftvafa air cover when a Catalina flying boat finally relocated Bismar on May 26.

The battleship was less than 24 hours from rescue.

The home fleet’s battleships were running low on fuel.

Admiral Tovi calculated he would have to abandon the chase by midnight.

Everything depended on slowing Bismar down.

The only weapon within range was a squadron of fabric covered biplanes with open cockpits, fixed landing gear, and a top speed of 139 mph.

Naval experts considered the ferry swordfish a relic.

It looked like something from the previous war.

Bismar’s crew had 16 10.5 cm anti-aircraft guns, 16 3.7 cm guns, and 12 2 cm cannons to shred anything that came close.

15 swordfish launched into a force 8 gale anyway.

By nightfall, Bismar’s rudders were jammed.

She could only steam in circles.

The ridiculous biplane had crippled a battleship that outweighed it by a factor of 7,000 to1.

The Swordfish had no business being in frontline service by 1941.

It entered fleet airarm service in July 1936 with 825 Naval Air Squadron.

By the time war began in September 1939, it was an anacronism.

The Mark 1 was powered by a Bristol Pegasus 3M3, a 9-cylinder aircooled radial engine producing just 690 horsepower.

Maximum speed with the torpedo was 138 to 143 mph at 4,750 ft.

Cruising speed was 104 mph.

The airframe was a skeleton of welded steel tubing covered in doped fabric.

The biplane wings were fabric over metal.

The cockpit was open to the elements.

The undercarriage was fixed.

A crew of three sat in tandem open cockpits.

The pilot forward, the observer in the center, the telegraphist air gunner facing rearward with a single303 caliber machine gun.

One pilot described the armament as one stage above the bow and arrow.

For context, the Supermarine Spitfire Mark1 reached 362 mph.

The messes BF109E hit 354.

Even the Japanese Nakajima B5N torpedo bomber managed 235.

The Swordfish was 2 and a half times slower than contemporary fighters.

In a world of enclosed cockpits, retractable gear, and all metal construction approaching 400 mph, it looked like a museum exhibit.

Its intended replacement, the Ferry Albaore, entered service in March 1940.

an improved biplane with an enclosed heated cockpit and a more powerful Bristol Taurus engine producing over 1,000 horsepower.

The Albore was supposed to retire the Swordfish.

In one of the war’s richest ironies, the Albore left frontline service in late 1943.

The Swordfish soldiered on until May 1945.

The aircraft it was meant to replace outlasted it by 18 months.

So why could the Royal Navy not simply use something faster? Because every torpedo bomber, regardless of top speed, had to slow down to between 80 and 120 mph for torpedo release, the American TBD Devastator could reach 206 mph in level flight.

At the Battle of Midway in June 1942, 41 Devastators attacked Japanese carriers.

35 were shot down, 85% losses.

Not a single torpedo hit.

The Swordfish simply started near its attack speed.

No vulnerable deceleration phase, no long straight approach at an unfamiliar handling regime.

The crew flew the aircraft the same way they always flew it, right into the attack.

Weather was the Swordfish’s second advantage.

Its stall speed was so low that it could take off in a climbing turn at 55 knots.

In a 40 kn wind, its deck run was just 62 yd.

On the evening of May 26, conditions over the North Atlantic were brutal for 6 to 8 seas.

Gale force winds gusting to 50 mph driving rain cloud from near sea level to above 10,000 ft.

Faster, heavier monoplanes with higher stall speeds could not have operated safely in those conditions.

The Swordfish could, but the Swordfish still had to survive Bismar’s anti-aircraft fire.

And on paper, those defenses should have been overwhelming.

Bismar displaced 41,700 tons standard and 50,300 tons at full load, the largest warship in European waters when commissioned in August 1940.

She measured 251 m in overall length with a beam of 36 m.

Three sets of geared steam turbines fed by 12 high-press boilers generated over 150,000 shaft horsepower, driving her to 30 knots.

Eight 15-in main guns sat in four twin turrets, firing 800 kg shells to a range of over 36,000 m.

Belt armor reached 360 mm of crop cemented steel.

Turret faces were 360 mm thick.

22 watertight compartments and a double bottom running 83% of her length.

Approximately 40% of her combat weight was armor, the highest percentage of any World War II battleship.

She was a fortress of steel.

3 days earlier, her fifth salvo had split Hood in half.

Yet, Bismar’s anti-aircraft defenses carried fatal compromises.

The 16 10.5 cm guns were split between two incompatible mount types.

Forward guns sat on older mounts with different training and elevation characteristics than the newer aft mounts.

The fire control system never properly integrated them.

Worse, the best fire control directors originally built for Bismar had been delivered to the Soviet Union under a trade agreement.

The ship sailed with inferior partially unstabilized replacements.

The medium anti-aircraft battery of 16 3.7 cm guns fired single rounds handloaded at roughly 30 rounds per minute.

The Allied Bowfor’s 40mm gun achieved 120.

Bismar’s medium guns were widely considered the worst of the war.

Her crew had conducted only one practice session with the flat guns before deployment.

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The first Ark Royal strike on May 26 ended in disaster.

15 Swordfish armed with torpedoes fitted with magnetic influence detonators attacked what they believed was Bismar.

It was HMS Sheffield.

The magnetic pistols proved catastrophically unreliable.

Several torpedoes exploded on contact with the water.

Sheffield’s captain held fire and evaded.

One sheepish crew signaled back to the carrier.

Sorry for the kipper.

The fiasco had one critical consequence.

For the second strike, torpedoes were rearmed with contact detonator pistols.

The reliable Mark 12 contact fuse that would actually work.

At 7:10 in the evening on May 26th, 1941, 15 Swordfish launched from Ark Royal’s pitching deck.

Aircraft from 810,818 and 820 Naval Air Squadrons led by Lieutenant Commander Cud of 818 each carried a single 18in Mark12 torpedo,548 lb of steel and TNT with a 388lb warhead.

They found Sheffield at 7:55 in the evening.

Sheffield vetoed them to Bismar by signal lamp bearing 110° 12 m.

They climbed to 6,000 ft, split into subflights, then attacked from multiple directions between 8:47 and 9:25 in the evening.

Bismar fired everything: main battery, secondary guns, every available anti-aircraft weapon.

The 15-in guns created enormous water plumes intended to swat the biplanes from the sky.

One crew member recalled the whole aircraft shaking as if express trains were roaring past.

Two torpedoes struck home.

One hit the armored belt and midshipips on the port side.

Negligible damage.

The second hit the stern on the starboard side, tearing open the hull near the rudder assemblies.

Both rudders jammed at 12° to port.

The steering gear was wrecked beyond repair.

Engineers and divers worked in flooded compartments.

Nothing could fix it.

Bismar could only steam in circles, driven by the gale back toward the approaching British battleships.

Not a single swordfish was shot down.

All 15 returned to Ark Royal.

One aircraft came back with 175 counted holes in its wings and fuselage.

At 9:40 in the evening, Admiral Luchen signaled Berlin, ship unmaneuverable.

We will fight to the last shell.

Captain Vian’s destroyers harassed Bismar through the night, denying her crew any rest.

The final battle began at 8:47 on the morning of May 27 when HMS Rodney and King George V opened fire.

By 9002, a 16-in salvo from Rodney destroyed the bridge and main fire control.

By 9:31, all four main turrets were silenced.

Rodney closed to 3,000 yds, virtually point blank, and hammered the burning wreck.

At 10:39, Bismar capsized and sank, taking approximately 2,100 of her 2,221 crew with her.

Only 115 men survived.

The Bismar action was the Swordfish’s most famous hour, but not its first.

On the night of November 11, 1940, 21 Swordfish from HMS Illustrious attacked the Italian fleet at Toronto.

Three battleships, half the Italian capital ship strength, were knocked out in a single night for the loss of just two swordfish.

The Italian fleet withdrew.

The Mediterranean balance of power shifted toward Britain.

Lieutenant Commander Teeshi Naidito, Japan’s assistant naval attaches in Berlin, flew to Toronto in December 1940 to study the damage firsthand.

Toranto confirmed the feasibility of what became the attack on Pearl Harbor.

The Swordfish’s darkest hour came on February 12, 1942 during the Channel Dash.

Lieutenant Commander Eugene Mond led six Swordfish of 825 Naval Air Squadron from RAF Manston against the German battle cruisers Shanho and Naisenau in daylight under an umbrella of 250 Luftwuffer fighters.

The promised Spitfire escort never fully arrived.

All six swordfish were shot down within 20 minutes.

13 of 18 crew were killed.

No torpedo hits scored.

Essond received aostumous Victoria Cross.

Captain Hoffman of Shanhost watched from his bridge and remarked that the slow biplanes were flying into nothing but suicide.

The channel dash proved what the Bismar action obscured.

Strip away the storm, the darkness, the multiaxis approach, and the swordfish was horrifyingly vulnerable.

Every advantage present against Bismar was absent and every aircraft was destroyed.

In the Battle of the Atlantic, Swordfish found their ultimate role.

operating from escort carriers and merchant aircraft carriers, Mark 2 and Mark III variants armed with rockets, depth charges, and sentiment radar hunted hubot across the Mid-Atlantic Gap.

They credited with sinking at least 14 Ubot.

In September 1944, Swordfish from HMS Vindex sank four Ubot during a single Arctic convoy run.

The Swordfish is widely credited with sinking more Axis shipping tonnage than any other Allied aircraft across its 9-year combat career.

Total production reached 2,391 aircraft, 692 built by Ferry Aviation at Hayes, 1699 by Blackburn Aircraft at Sherburn in Elmet, affectionately nicknamed Blackfish.

Three main variants served across the war.

The Mark 1 original torpedo bomber.

The MK2 with metal lower wings for rocket rails.

The Mark III fitted with centimetric radar in a redome between the landing gear for submarine hunting.

The Swordfish served from 1936 to 1945.

The only fleet airarm type to serve throughout the entire war.

It earned more battle honors than any other British aircraft.

The Board of Admiral T’s postaction assessment of the Bismar Chase was unequivocal.

There can be no doubt, they wrote, that had it not been for the gallantry, skill, and devotion to duty of the fleet air arm in both victorious and ark royal, our object might not have been achieved.

Baron Burkard von Mullenheim Recreberg, Bismar’s senior surviving officer, watched the swordfish from his fire control position.

He later wrote of the pilots, describing their suicidal courage as if they did not expect ever again to see a carrier of the rudder hit.

He recalled watching the steering indicator read left 12° and waiting for it to change.

It never did.

The lesson is not that old technology is inherently superior.

The Swordfish demonstrates that capability is context dependent.

The Fleet Airarm matched tactics to the aircraft’s limitations.

Night attacks, storm weather operations, multiaxis approaches from cloud cover.

Crews trained relentlessly with live torpedoes.

The Swordfish succeeded not despite being obsolete, but because its obsolete characteristics, ultra- low stall speed, extreme maneuverability, fabric resilience, mechanical simplicity were precisely what certain missions demanded.

On the evening of May 26, 1941, in a North Atlantic gale at twilight, with rain lashing open cockpits and waves breaking over fabric wings, no aircraft on Earth could have done the job better.

A 139 mph biplane crippled a 50,300 ton battleship and changed the course of the war at sea.

The skeptics who called the swordfish a relic were not entirely wrong.

It was a relic.

It was also the weapon that stopped Bismar when nothing else could reach her.

British naval aviation did not have the fastest aircraft or the most modern technology.

What it had were crews willing to fly canvas bipplanes into the teeth of a gale and an aircraft stubborn enough to bring them home with 175 holes in its wings.

That was enough.