The ‘Ultimate’ Churchill Tank That Arrived The Same Week The War Ended | Too Late!

May 1945, Vauxhall Motors Factory, Luton.

Six brand new tanks rolled off the production floor.

Each one carrying the most powerful anti-tank gun in the British arsenal behind 152 mm of frontal armor.

They were the answer to every problem British tank crews had faced since the first Tiger appeared in North Africa 2 years earlier.

They were also 2 weeks too late.

The war in Europe ended on May 8th.

The production contract for 300 vehicles was cancelled on May 30th.

The A43 Black Prince, the ultimate Churchill, the most heavily armed and armored British infantry tank ever built, never fired a single shot in anger.

This is the story of a tank that could have changed everything.

Designed by engineers who solved every technical challenge except the one that mattered most, time.

To understand why the Black Prince existed, you need to understand the crisis that created it.

British tank crews in 1943 were in serious trouble.

The Churchill, Britain’s primary infantry tank, mounted a 75mm gun with the same ballistics as the American M3.

It was adequate against infantry positions and lighter vehicles.

Against German heavy armor, it was useless.

The Tiger 1 carried 100 mm of flat frontal armor.

The Churchill 75 mm gun could not penetrate that plate at any practical combat range.

The Panther presented 80 mm of glacis armor sloped at 55°, yielding roughly 139 mm of effective thickness.

The 75 mm could not defeat that either.

British crews were fighting tanks they simply could not kill from the front.

German crews knew it.

The first Tiger tanks appeared in North Africa in early 1943.

The situation was so urgent that the first 100 prototype 17 pounder anti-tank guns were rushed to the front mounted on 25 pounder howitzer carriages came before proper gun carriages even existed.

Britain did have a weapon that could solve the problem.

The Ordinance quickfiring 17 pounder was a 76.2 mm anti-tank gun capable of penetrating 163 mm of armor at 500 m with standard armor-piercing ammunition.

With the newer discarding Sabbath round, that figure jumped to 256 mm at the same range.

This gun could kill a Tiger frontally at well beyond 1,700 m.

As a towed weapon, it was devastating.

The challenge was putting it inside a turret where it could move with the armored advance.

The problem was fitting it inside a tank.

The 17 pounder was physically large and heavy.

No British tank turret in production could accommodate it.

The Churchill’s hull was too narrow, constrained by pre-war railway loading gauge restrictions to accept a turret ring wide enough for the weapon.

Multiple programs ran in parallel to solve this crisis.

The Challenger mounted the 17 pounder on a lengthened Cromwell hull, but suffered production delays and was disliked by crews.

The Sherman Firefly squeezed the gun into a modified Sherman turret and became the first successful 17p pounder tank, proven in combat from D-Day onward.

The Archer mounted the gun backwards on a Valentine chassis.

Each was a compromise.

None combined the 17 pounder with the heavy armor protection that Churchill crews depended on for survival.

In September 1943, the War Office asked Vauxhall Motors to produce something that did.

Vauxhall at Luton had designed every variant of the Churchill since the tank’s inception.

Their engineers knew the hull’s strengths and limitations better than anyone.

The formal specification for the A43 was issued on December the 2nd, 1943.

It called for a widened Churchill hull carrying the 17 pounder in a new turret adapted from the A41 Centurion design with frontal armor of 152 mm and a target weight of approximately 50 long tons.

The name chosen was Black Prince after Edward the Black Prince, the 14th century English military commander.

According to tank archives, many Royal Navy ships had carried this name over the centuries, though with mixed fortunes.

Before cutting any steel, Vauxhall conducted a clever preliminary test.

They took a standard Churchill, fitted it with a new 5-speed gearbox, and added ballast to bring it up to 50 tons.

On December 28th, 1943, this weighted tank was tested against the A 33 Excelsia heavy assault tank and performed in Vauxhall’s assessment hardly worse.

This gave the engineers confidence to move forward.

The hull grew roughly 70 cm wider than the Churchill Mark 7.

An extra road wheel was added on each side.

Tracks widened to 24 in to distribute the additional weight.

Air intakes moved from the hull sides to the hull top.

The turret ring expanded to 1880 mm to accept the 17 pounder.

The tank carried 89 rounds of main gun ammunition in three types.

Standard armor-piercing discarding Sabbat and high explosive.

Two 7.92 mm Bisa machine guns provided secondary armorament, one coaxial and one in the hull bow.

A crew of five operated the vehicle.

The engine was the critical weak point.

Vauxhall retained the Bedford Twin 6, a horizontally opposed 12-cylinder petrol engine, producing 350 brake horsepower.

This was the same engine that powered the 40 ton Churchill Mark 7.

In the 50 ton Black Prince, the powertoweight ratio dropped to roughly 7 horsepower per ton.

According to tank archives, the director of the Royal Armored Corps pointed out that using this engine in a tank 10 tons heavier, would make it critically underpowered.

His protests were brushed aside.

Plans existed to install a 600 horsepower Rolls-Royce Meteor, the same engine that would make the Centurion so successful.

This upgrade never left the drawing board.

Tank Archives notes it would have required major redesigns to the hull, defeating the purpose of what was meant to be a rapid adaptation of existing Churchill components.

In May 1944, six prototypes were ordered alongside a contract for 300 production vehicles with deliveries projected to begin the following spring.

A full-sized wooden mockup was completed by August.

The first prototype rolled out in January 1945, delayed partly because Vauxhall received the wrong gun variant from the factory.

By May, all six were delivered.

The war ended in the same week.

Now, before we get into how this tank performed in trials and how it stacked up against everything else on the battlefield, if you are enjoying this deep dive into British engineering, consider subscribing.

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Now, let us get into the results.

Each prototype was assigned a specific testing role.

Two stayed at the factory.

One went to Lworth in Dorset for gunnery trials.

One underwent penetration testing.

One was subjected to extended usage trials.

The sixth tackled deep water waiting tests.

The Lullworth gunnery trials in March 1945 produced an encouraging official report.

It praised the armament and turret arrangement as successful.

The tank proved to be a stable firing platform with effective ventilation and good visibility from the commander’s position.

The 17 pounders performance in the roomy new turret was everything the designers had promised.

But the problems ran deeper than any gun could fix.

Top road speed was 10.5 mph cross country.

That dropped to roughly 7.5 mph.

To put that in perspective, a person jogging at moderate pace would outrun this tank.

The five-speed gearbox that replaced the Churchill’s four-speed unit made things worse.

The gear ratios were too close together, and drivers had to change within 1.5 seconds to avoid stalling the engine entirely.

A firstirhand account adds texture to the official records.

Rob Cook, whose father, John Cook, was stationed at Bovington and drove the Black Prince during trials, later recalled his father saying the tank was difficult to drive because it had no brakes.

Drivers relied on the gears exclusively.

This is consistent with the Churchill’s regenerative steering system, but the experience was clearly worse at 50 tons.

Testing crews also criticized the flat fronted hull.

They recognized that sloped armor was the way forward.

A lesserknown detail explains why the Black Prince kept its archaic flat face despite British engineers having studied a captured Panther and fully understanding the advantages of angled plate.

The A43 was intended to double as a flamethrower tank.

A sloped front would have made that conversion very difficult.

This secondary role never materialized, but it constrained the primary design throughout development.

One persistent myth deserves correction.

Some accounts claim Blackprints prototypes were sent to the front lines, but arrived after the fighting stopped.

According to historian Yuri Pasholock, working from original wartime documents, this is not true.

Unlike the Centurion, which was indeed dispatched for frontline evaluation, the Black Prince never left British testing grounds against the tanks.

It was designed to fight.

The numbers told a compelling story.

The Tiger 1’s 88 mm gun firing standard armor-piercing ammunition could penetrate roughly 151 mm at 500 m.

The Black Prince’s frontal plate was 152 mm.

That single mm margin meant the Tiger could not reliably penetrate the Black Prince’s front at typical combat distances.

The Panther’s 75 mm gun achieved roughly 149 mm of penetration at pointblank range.

still insufficient to defeat 152 mm, even with the muzzle touching the plate.

No other Allied tank in 1945 could make that claim.

While simultaneously carrying a gun powerful enough to destroy both German heavies at long range against the Sherman Firefly, which carried the identical 17 pounder, the trade-off was brutal.

Both tanks could kill the same targets.

The Firefly had nearly double the power to weight ratio and more than double the road speed at 25 mph.

Over 2,100 were produced and battle tested across northwest Europe.

The Black Prince offered superior protection, 152 mm versus the Sherman’s 50 to 89 mm, but the Firefly already existed in quantity, was proven in combat, and could keep pace with an advancing army.

The AmericanM26 Persing and Soviet Yes2 both use sloped armor to achieve comparable or superior effective protection at significantly lower weight.

Both were far faster.

The IS-2’s 122 millimeter gun delivered devastating singleshot power, but fired only two to three rounds per minute compared to the 17 pounders roughly 10.

The Black Prince was the most heavily armored tank in its weight class.

It paid for that armor with mobility that was already unacceptable by 1944 standards.

The 300 vehicle production contract was formally cancelled on May 30th, 1945, 3 weeks after VE Day.

The War Office’s attitude toward the program had been telling from the start.

Only six prototypes were ordered, compared to 20 for the Centurion.

Tank Archives notes that department leadership saw such low figures as proof the military had never taken the Blackprint seriously.

It was ordered more as a way to cover all their bases than as a genuine commitment to production.

A photograph from the trials shows a Black Prince prototype parked beside the rather sorry remains of a Churchill Mark1.

Tank Archives describes this image as one that was supposed to show progress, but instead makes for an effective epitar.

Britain’s first and last infantry tanks side by side.

The Centurion offered the same gun with equivalent effective frontal protection through sloped armor, used the meteor engine the Black Prince never received, achieved a top speed of over 20 mph, and weighed 5 tons less.

It was a superior vehicle in every measurable respect.

The Black Prince’s influence endured through an unexpected lineage.

Work on the A45, a heavy tank concept from 1944, eventually produced the FV201 prototype.

That vehicle’s hull was repurposed for the FV214 Conqueror, Britain’s Cold War heavy tank, which served with the British Army of the Rine into the 1960s.

The chain of development runs directly from the Black Prince’s canceled ambitions through to the tanks that faced down Soviet armor in Germany.

Five of the six prototypes were scrapped.

One survivor sits at the Tank Museum Boington, restored to running condition, and demonstrated at Tankfest events.

Tank Archives notes that even in museum appearances, the gearbox routinely gives trouble.

A fitting final echo of the design’s original curse.

May 1945, Vauxhall Motors Factory, Luton.

Six tanks that could shrug off a Tiger’s best shot and kill it in return at ranges the German crew could barely see.

Six tanks too slow to keep pace with a man on a bicycle.

The Black Prince was the last British infantry tank ever designed.

It proved conclusively that the infantry tank doctrine had reached its end point.

You could not keep adding armor and armament without addressing the engine underneath.

The Centurion answered that lesson and went on to serve for half a century across dozens of nations.

British engineers at Vauxhall solved the gun problem.

They solved the armor problem.

They solved the turret ring problem.

The engine problem defeated them.

Not because they lacked the talent, but because the schedule demanded an interim design built from existing components.

The Meteor installation that would have transformed the Black Prince required a redesign there was no time to complete.

The A43 Black Prince stands as proof that British engineers could build a tank the enemy could not kill.

It stands equally as proof that in war, arriving late, no matter how good your engineering means arriving irrelevant.

The documents confirm it.

The specifications prove it.

And one surviving prototype at Bovington, gearbox still grinding after 80 years, tells the story better than any words ever could.

British engineering was not the problem.

Timing was