What were tanks used for in WW1?

On 31 May 1918, a small tank designed by a famous French car maker and a brilliant army officer saw its first action. Its inspired design still lives on in the tanks of today, 100 years later.

On 31 May 1918, the German army launches a sudden attack near the Forest of Retz near Ploisy in the north-east of France. It is the last year of World War One, and the Germans are desperately trying to beat the Western Allies.

A British blockade is crippling the German economy. Those back at home are suffering shortages of fuel and food. The German Empire faces starvation and defeat.

As the French units at Retz try to resist the onslaught, they are joined by reinforcements. Among them is a new tank: the FT. Compared to the giant, lumbering British tanks that have been used with mixed results for the past 18 months, these are tiny. There is only room for two people inside them.

But they are remarkably effective. The 30 tanks rushed to this battle help to push the Germans back. The tanks only stop advancing because the accompanying infantry cannot keep up with them.

At the site of this action, a century later, there is now a plaque, commemorating the first use of what is arguably the ancestor of every modern tank. The tiny FT is a paradigm of far-sighted design.

And it owes its existence to an unlikely pairing: a pragmatic artillery officer and one of France’s most renowned carmakers.

***

It is a modern myth that the arrival of the tank – a lumbering vehicle bristling with guns – helped end World War One in a matter of weeks.

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They helped turn the tide on the Western Front, but this did not happen overnight.   

Since the end of 1914, the German and Anglo-French armies had faced each other across trench networks in virtual stalemate.

The war on the Western Front had been characterised by sudden offensives, as one side tried to break through the other’s lines with massive artillery bombardments followed by tens of thousands of men attacking via no-man’s land.

German machine gun positions made infantry assaults across no-man’s land very difficult (Credit: Getty Images)

But advancing technology had made these attacks almost unbearably costly. Barbed wire was difficult and time-consuming to clear. Machine guns could cut down man after man from hundreds of yards away. Concrete bunkers and well-built trenches protected enemy soldiers even from the bombardment of hundreds of guns.

Both the British and French worried they would run out of soldiers from failed frontal assaults before the German defences could be breached.

A handful of inventors and visionary engineers arrived at the same idea – build some kind of armed and armoured vehicle that could create gaps in the barbed wire, knock out machine gun posts and bunkers, and protect infantry long enough for the trench networks to be captured.

“It’s an answer to the problem of how to push out an occupying army,” explains David Willey, curator at the Bovington Tank Museum.

“The French and the British and then the American leaders want to use armour plate instead of using, as it were, the blood from the soldiers’ breast. They have to re-learn fighting in this modern age.”

The first tanks clambered onto the battlefield in September 1916. A British design called the Mark I, the giant, lumbering vehicles couldn’t move much faster than a walking man – but they were practically impervious to machine gun fire. Early on, just the sight of them had been enough for some German strongpoints to surrender.

The British tanks had some success, but were slow, ungainly, and difficult for their crews to operate (Credit: Getty Images)

But the Mark I had its limitations. The British had rushed it into service before engineers had ironed out teething problems, and many of the tanks broke down due to mechanical issues. They were dark, noisy, furiously hot and cramped. Engine fumes and flammable materials could turn them into a death-trap in an instant.

Their slow speed made them relatively easy targets for artillery. And while they were armed with cannons and machine guns, these were arranged on their sides, meaning the whole vehicle had to be moved to bring them to bear.

The British constantly updated this basic design, seeking to turn it into a ‘wonder weapon’. An improved version, the Mark IV, came into service in 1917.

But both the Mark I and Mark IV were cumbersome and unwieldy, their rhomboid shape designed to allow the tracks to crush barbed wire beneath them rather than for speed or manoeuvrability. The idea was that the new tanks would operate in concert with infantry, travelling slowly enough that troops could shelter behind them.

For some, it was clear that something smaller and lighter would be needed to cover ground once the impediment of the trenches had been left behind.

***

Jean Baptiste Eugene Estienne was considered one of France’s most visionary artillery commanders. He was a gifted mathematician, a philosopher and a lifelong student of Ancient Greece.

He also saw how new technology was changing warfare. He was an early pioneer of indirect fire – guns firing at the enemy from behind cover, guided by an observer – and worked on machinery that would make this possible. In 1907 he became head of the artillery school in Grenoble.

The first French tank design, the Schneider CA1, was not considered a success (Credit: Alamy)

Even before the war broke out, Estienne had realised the military role aircraft would play – in particular how planes could be used to guide artillery fire. In the opening weeks of World War One, Estienne used aircraft to direct artillery shells to devastating effect at the Battle of Charleroi, as German armies poured across Belgium and north-eastern France.

But his visionary ideas extended far further than aircraft. He saw that machine guns and massed rifle fire made frontal infantry attacks very dangerous – and that troops might need to use some kind of mobile armoured shields to protect themselves when they were advancing.

As early as August 1914, Estienne believed a gun-armed, armoured vehicle could be decisive in the coming conflict. "Gentlemen, the victory in this war will belong to which of the two belligerents which will be the first to place a gun of 75 [mm calibre] on a vehicle able to be driven on all terrain," he told a group of French artillery officers in 1914.

Estienne got permission to create a prototype from French military commander General Joffre. Estienne then approached one of France’s most respected car designers, Louis Renault, to build it.

Renault’s factories were already busy making other vehicles and the carmaker declined to get involved. The design, mounted on a US-built Holt tractor, it was too ambitious a project for an engineer unused to building tracked vehicles. So Estienne went instead to the engineering firm Schneider, which had built France’s first operational tank, the CA1.

Like the British tanks, the CA1 was huge and slow, designed to cross the crater-strewn no-man’s land and drive over enemy trenches. But unlike the British tanks, the CA1 and its sister the Saint Chamond were not effective designs.

“These French designs are pretty terrible,” says Willey. “They’re basically sticking a 75mm gun at the front of a large tractor, but they’re nowhere near as good as the British tanks.”

But Renault did have another idea. He thought that once the trenches and shellhole-strewn landscapes were crossed, there would be urgent need for a much smaller and lighter tank – one able spread out and attack enemy formations from the rear, in much the same way cavalry had done over the centuries. Renault also realised that contemporary engines wouldn’t be able to move a heavy tank across such difficult terrain at a useful speed.

Barbed wire had been very difficult for infantry to deal with before tanks arrived (Credit: Getty Images)

He decided to create something much lighter. The British Mark IV could weigh as much as 29 tonnes, but the new tank would weigh only seven tonnes, making it less likely to get bogged down in the soft, shell-cratered ground between the trenches.

Renault worked with designer Rodolphe Ernst-Metzmaier on the new tank.

It sported several revolutionary features. It was the first to carry its armament – either a machine gun or a 37mm cannon – in a turret that could spin 360 degrees. While the British tanks had crews of up to 12, this one was controlled by a driver sitting in the front and the turret by the commander/gunner directly behind him. And the engine was located in the rear, in a separate compartment – a configuration that almost every tank since has adopted.

The British too had a tank that swapped a heavy cannon for machine guns – this model, the Whippet, would see action in the final battles of 1918. But the Whippet’s engine was at the front, its crew compartment did not have a revolving turret.

There were other innovations hidden under the hood of the Renault machine. The tank cooled its engine by sucking in air from the front of the tank and expelling the heated air out the back. This made it a much more comfortable vehicle to drive in than the Mark I or IV.

The designers also ensured that the engine could work when tilted at steep angles, meaning the tank could climb in and out of deep shell craters without stalling.

French tactics called for large groups of FTs to swarm enemy lines (Credit: Alamy)

As a result, the FT’s two-man crew travelled in relative – if cramped – comfort in a vehicle able to travel as fast as 7mph (11km/h), a speed not to be sniffed at in 1918. The plan was to use swarms of these small tanks with accompanying infantry to overwhelm enemy defences, burst through the trenches and then fan out.

The French high command saw the design’s promise and drew up plans to produce more than 12,000 before the end of 1919. Renault couldn’t make more than a fraction, so other carmakers also set up production lines.

As 1918 wore on, more and more FTs were produced, allowing them to be used in larger numbers. The last months of 1918 saw the kind of open warfare the FTs were designed for as the German defences crumbled and their armies retreated swiftly through France and Belgium.

FTs were widely used after World War One, inspiring similar designs in countries such as Italy and the USSR (Credit: Getty Images)

“It’s part of that final nail in the coffin for the Germans,” says Willey. “They are being blockaded by the British and running out of fuel and food. When you started to see the German memoirs in the 1920s asking the question ‘why did we lose’, the tank was always mentioned.”

Willey says the tank symbolises the fact that the Western Allies – strengthened by the industrial might of the US from 1917 – were going to win. By the end of the war, the Germans only built about 20 tanks. In the time it had taken them to build those, the French had produced more than 1,000 FTs.

“When it’s a war for national survival, this is the kind of thing people come up with,” says Willey.

It was an approach that was to prove devastatingly effective in the years to come.

In 1929, the British Army’s practice manoeuvres on Salisbury Plain used small, fast tanks inspired by machines like the Whippet and the FT – and drew the interest of German commanders. They would combine these tactics alongside aircraft and artillery in a new style of warfare called ‘Blitzkreig’, barely a decade later.

***

One hundred years after it first trundled off the production lines, the FT doesn’t look like something that would give you nightmares.

At just over 16ft (4.8m) long and less than 6ft (1.8m) wide, the FT seems less like a death-dealing weapon of war and more like a vintage tractor with a turret. A modern battle tank like the US M1 Abrams is twice as long, twice as wide, and weighs eight times as much. Like the famous British Matilda I tank of World War Two, there’s the faint resemblance to a cartoon duck.

To see one today, BBC Future has travelled to a farm in the middle of Kent in southern England. It is, at least on the surface, a perfectly normal English farm. A pair of Sussex-breed bulls munch hay in their pens. A couple of friendly old terriers hover around a workshop in one of the farm buildings.

The Renault FT, working after 100 years

 The Renault FT, working after 100 years

Inside this workshop are two Renault FTs – one of which was only restored back to running condition a week ago, the first time it has functioned in nearly 100 years.

The other, a specialised version which contained an early two-way radio, is slowly taking shape as well. Each tank has taken three years’ work to get to this stage.

The FTs are part of a collection owned by South African farmer Mike Gibb, a former soldier who has a fascination with armoured vehicles. He set up the Weald Foundation in 1997 to restore old armoured vehicles to working condition.

Originally, the foundation concentrated on German vehicles from World War Two that weren’t in national collections. The workshop’s array includes staff cars, amphibious jeeps and two Stug tank destroyers, which were anti-tank vehicles built by Germany during World War Two. The restorers who work at the farm workshop have full diaries until 2032.

The FT is the oldest tank they have brought back to life. It is quite common to see an FT as part of a museum collection – but rare to see one actually able to move under its own power.

The team have painstakingly restored the running FT. Even the tiny petrol can the crew used to start the engine – pouring a small amount fuel directly onto the cylinders – has been rebuilt from old blueprints. Experts from around the world, including the Bovington Tank Museum, France’s equivalent museum and even the Brazilian Army, have pitched in to help.

“We didn’t know that you actually get First World War vehicles,” says Gibb. “A First World War one vehicle is like a lunar lander for collections. When we did find you could actually get hold of one, that was a huge event.

“The option then of saying no just wasn’t there. We had to do it.”

Engineer and driver Martin Trowsdale slowly guides the tank down ramps from the workshop (Credit: Stephen Dowling)

Gibb says the team started sourcing parts for the FT back in 2008. They got hold of two partly intact tanks, and started merging them to create one working vehicle.

The more they worked on the FT, the more they discovered. Heat-treating the hatches at the front of the tank – which allow the driver to get in and out with a little bit of gymnastics – brought out identification marks that had been written in chalk when the tank was being built. From it, they could work out that it had been made in the Renault factory in June 1918.

Other photos, says Gibb, showed the kind of camouflage that had been painted on vehicles built around the same time. And even though they were in black-and-white, with a little detective work they could recreate the exact colour scheme. The completed FT was painted with the help of Guy Portelli, a sculptor who was once a successful contestant on the BBC’s Dragon’s Den.

Parts were found in strange places. The tank’s turret, which housed a machine gun, was found in someone’s garden, where it had pride of place on top of a rockery.

“I don’t know how pleased the man’s wife was with this design,” says Gibb. “And also the colour – the camouflage was pink and light blue and some other colour!”

The FT’s turret was made by Fichet, a company now renowned for its handiwork in a completely different area. “Today, I believe they’re the largest safe suppliers in Europe,” adds Gibb.

The FT was designed to drive as fast as 7mph – so that infantrymen could still keep up with it (Credit: Stephen Dowling)

The FT had a long life. It was still a front-line tank more than 20 years later at the start of World War Two in both the Polish and French armies. By this time, however, it was considered slow and offered poor protection from anti-tank weapons.

Nonetheless, hundreds of FTs were committed to battle when the Germans invaded France in May 1940. Even afterwards, the Germans found use for them. They patrolled occupied Europe, protecting supplies, guarding airfields and supporting police.

When the Allies invaded Normandy in June 1944, they encountered FTs in German markings, thrown into the frontline in desperation. The last examples used in combat were in the Arab-Israeli War of 1948.

Because the FT was updated through the 1920s and 30s, piecing together the details of its design from 100 years ago was a painstaking task for the team at the Weald Foundation. After all, it’s not as if you can ring up one of the engineers who helped build them and find out what goes where.

It would be a shame to come all this way and not see the FT go for a spin. Weald Foundation engineer Martin Trowsdale climbs into the tank’s cosy driving compartment, and the FT shudders its way down metal ramps onto the concrete driveway.

Take a ride on the Renault FT

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Its pace is still pedestrian, but still the FT could travel twice as fast as some of its bigger contemporaries. The Weald’s FT negotiates its way around the farm buildings with a growl, before demonstrating its cross-country ability across one of the farm’s paddocks.

“Because it’s so slow, you don’t have to react like when you’re in a car and you’re expecting people to run out in front of you,” says Trowsdale later. “This just sort of chunters along. It gets boring after a while!

“Physically it’s not difficult, there’s nothing heavy about it, although the gear shift is rather prone to catching your knuckles when you’re changing gears, because there’s a bracket that sticks out by the gearknob, and it takes the skin off every time.” He holds up his hands to show the damage.

But, he says, with two levers for turning left and right, a throttle, a clutch and a brake, “it’s basically a simple thing to drive”.

Renault_Tank_DRIVING_1920x1080.mov

What it's like to drive the FT

Trowsdale spent nine months rebuilding the engines for the two tanks. “All the bearings and things on the main crankshaft, you can’t go down the shop and buy new shells for the bearings – they don’t exist. We had to make them. We had to pour white metal bearings into the shells, machine them and then scrape them in. That’s a long, slow process. It’s not a skill that still exists.

“Funnily enough, I used to do it when I was an apprentice many, many years ago. But they don’t teach kids to do these things anymore.”

The crew even rebuilt the original gearbox – which had some of the gears still working. “Top gear seemed to survive better than most, because they didn’t use it that much!” says Trowsdale with a laugh.

And the radiator is a Victorian contraption comprised of some 1,300 tubes. Each tube had to be welded by hand.

With the first FT fully restored, now the team is starting work on the radio version, which they hope will be driving around the farm in a few weeks.

If it does rumble back to life, the Weald team will have been responsible for two of only seven FTs still in running condition. But, Gibb says, they’ll have shown others that the task isn’t an impossible one – and that Louis Renault’s tiny, pioneering tank can live on.

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