America’s FORGOTTEN Masterpiece of WWII That DOMINATED The Wehrmacht

It is the decisive arm of the modern battlefield, artillery.

And in the Second World War, no army on Earth was more obsessed with the power of artillery than the United States Army.

But a powerful cannon is useless if it can’t keep up with the battle.

As the German Blitzkrieg proved, the new way of war was speed.

The German answer to this problem was the self-propelled gun.

machines like the Vespie or Wasp.

They took their existing and often obsolete tank chassis, mounted a field howitzer on top, and created a mobile artillery piece that could keep pace with the panzers.

It was a clever, coste effective, and deadly solution.

The American answer was not just a gun on a chassis.

It was a complete purpose-built weapon system, the M7 Priest.

It was bigger, more heavily armed, and designed from the ground up for the American doctrine of overwhelming unstoppable firepower.

It was so effective, so reliable, and so beloved that it became the standard self-propelled gun for the entire Allied war effort.

This is the story of two approaches to mobile artillery and why the American masterpiece dominated the battlefield.

The likely felt habits 18 of Fargashel Pansa Vagen 2 better known as the Vespa was a weapon born of desperation and ingenuity on the brutal Eastern front.

The German army’s standard 10.5 cm lefth field howitzer was an excellent weapon, but it was horsedrawn in the vast muddy steps of Russia.

It simply couldn’t keep up with the panzer divisions.

The solution proposed in 1942 was brilliantly simple.

The Panzer 2 light tank was by this point in the war completely useless as a combat tank.

So German engineers took the Panzer 2 AUSF chassis, removed the turret, moved the engine forward to the middle of the vehicle, and built a thin open topped armored box at the rear to house the 10.5 cm howitzer.

It was a cost-effective way to get a mobile gun to the front quickly, recycling an obsolete chassis.

But it was a machine of compromises.

It was small, cramped for its five-man crew, carried a very limited amount of ammunition, and its armor was paper thin.

It was a good solution, but it was a stop gap.

The American M7 Priest, by contrast, was a purpose-built weapon system born from the US Army’s doctrine of total mechanization.

As early as 1941, the Armored Force Board knew they needed a powerful, reliable, self-propelled howitzer to equip their new armored divisions.

After a brief experiment with a prototype on a light tank chassis, the designers made a critical and war-winning decision.

They would base their new vehicle, the T32, on the chassis of the M3 Lee medium tank.

This meant the M7, as it would be standardized in 1942, shared the same powerful Continental radial engine and rugged, reliable suspension as a frontline battle tank.

It was mechanically robust, easy to maintain, and could keep up with the Sherman tanks it was designed to support.

Its fighting compartment was huge.

Its main weapon was the superb American M2A1 105 mm howitzer, a gun renowned for its accuracy and reliability.

And for self-defense, it carried the legendary M2 Browning50 caliber machine gun.

It was mounted in a distinctive raised ring that gave the gunner a commanding view.

British soldiers upon seeing this for the first time remarked that it looked like a church pulpit and the nickname priest was born.

It was a complete and brilliantly thoughtout design.

Both vehicles were armed with the standard lightfield howitzer of their respective armies.

The German 10.5 cm and the American 105 mm.

Both were excellent, highly effective guns capable of providing devastating indirect fire support with a range of over 11,000 yards.

The difference, however, was in the platform.

The small, cramped Westb could only carry 32 rounds of ammunition.

This was a critical limitation.

In a prolonged battle, it would quickly run out of shells, forcing it to withdraw or wait for a vulnerable unarmored ammunition carrier to arrive.

The M7 Priest, with its large medium tank chassis, was a mobile arsenal.

It could carry 69 rounds of ammunition, more than double its German counterpart.

This meant a priest battery could sustain a barrage for much longer without needing to be resupplied.

A critical advantage in a fast-moving battle.

Verdict: A decisive victory for the M7 Priest.

At their core, these vehicles were a marriage of a gun and a tank chassis.

The Vespie was built on the chassis of a Panzer 2 light tank.

This gave it good mobility for its time with a 140 horsepower Maybach engine and a top speed of around 25 mph.

It was agile and capable of keeping up with the Panzer divisions it was designed to support.

The M7 Priest, however, was built on the chassis of an M3 medium tank.

This was a heavier, more powerful foundation.

It was powered by a massive 400 horsepower Continental radial engine and featured the rugged and reliable vertical vollet spring suspension or VVSS, the same system used on the M4 Sherman.

This gave it a higher top speed of up to 30 mph on roads and its wider tracks gave it superior cross-country performance in the mud and broken terrain of Europe.

It was fundamentally a medium tank chassis versus a light tank chassis.

Verdict: A clear victory for the M7 Priest.

Its more powerful, robust, and reliable medium tank chassis gave it superior tactical and strategic mobility.

A weapon is only as good as the men who operate it.

And here the design philosophies had a profound impact on the crews.

The Vespe was incredibly cramped.

Its fiveman crew were packed into a small boxy compartment with the massive breach of the howitzer dominating the space.

In a sustained firefight, this crowded environment would have been a chaotic nightmare of tangled limbs, hot brass casings, and shouted commands.

The M7 Priest, by contrast, was designed around the crew.

Its large open fighting compartment was comparatively spacious.

The American doctrine called for a larger crew of seven men, which allowed for redundancy and the ability to split duties.

This space was not a luxury.

It was a combat multiplier.

It allowed the canonners to pass and load the heavy 105 mm shells with speed and efficiency, dramatically increasing the sustainable rate of fire.

The famous war correspondent Ernie Pile, who spent significant time with priest crews, noted their incredible teamwork, a direct result of a design that gave them the room to do their jobs properly.

Verdict: A decisive victory for the M7 Priest.

Both the Vespe and the Priest were open topped vehicles, making their crews highly vulnerable to air bursting artillery.

However, the Priest’s design gave it a significant edge in protection.

The Vespe, built on a light tank chassis, had a maximum of 30 mm of armor on its front.

Its super structure was even thinner.

The M7 Priest, built on a medium tank chassis, had up to 51 mm of frontal armor.

This gave its crew and internal components, particularly the large ammunition stores, a much higher degree of protection from counterbatter fire and small arms.

More importantly, the Priest’s50 caliber machine gun gave it a powerful defense against attacking infantry and crucially against the strafing enemy fighter bombers that were a constant menace.

The Westby’s crew with only a single light machine gun could do little against an attacking P47.

Verdict: a clear victory for the M7 priest.

The Vespe was a clever, cost-effective design, and Germany produced around 676 of them.

They served effectively, primarily with the Panzer divisions on the Eastern Front.

The United States produced over 4,300 M7 priests.

It wasn’t just a vehicle.

It was an industrial title wave that allowed the US Army to fully mechanize its artillery battalions.

But its impact was global.

Under Lend lease, the priest became the standard self-propelled gun for the British Eighth Army in North Africa, where it played a decisive role at the second battle of Elamagne.

The British loved the vehicle, but had one major complaint.

Its American 105 mm gun complicated their ammunition supply, which was based on their own excellent 25pounder.

This led them to create their own version, the Sexton.

But the priest was the vehicle that set the standard and proved the concept of a fully mechanized hard-hitting artillery force for all the Western Allies.

Verdict, a crushing strategic victory for the M7 Priest.

The German Westpe was a brilliant piece of battlefield improvisation.

It was a smart, cost-effective solution that gave the German army a mobile artillery piece when they desperately needed one.

It was a weapon born of scarcity.

But the M7 Priest was a weapon born of abundance and foresight.

It was a masterpiece of industrial design and clear, focused doctrine.

It was more survivable, carried more ammunition, and was built on a more reliable and powerful chassis.

It was designed from the start to be the backbone of a modern, mobile, and unstoppable artillery force.

The Vespe was a clever stop gap.

The M7 Priest was a war-winning weapon system.

It was the chariot that allowed American and Allied artillery to dominate every front deserts of Africa to the heart of Germany.

What do you think is the most underrated but essential support vehicle of World War II? Let us know in the comments below.

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