70,000 gallons of fuel left the depot in North Africa.

30,000 gallons reached the front.

A 57% loss.

The quartermaster in charge logged it as “a good effort.”

That was Allied logistics in the desert war: fuel columns bleeding themselves out across sand and rock before the enemy even fired a shot. The catastrophe had a face—thin tin cans soldiers called “flimsies”—and a solution that had existed for years in enemy hands. The Americans would eventually copy that solution. Then change one invisible detail.

And turn German perfection into a leaking disaster.

September 1942. Egypt.

A soft-spoken American chemical engineer named Richard M. Daniel climbed out of a transport aircraft and into a world of sand, sun, and gasoline fumes. The War Department had sent him to investigate reports of catastrophic fuel losses. What he found was worse than anything the paperwork hinted at.

Between the port and the front line, British quartermasters reported losing 30 to 40 percent of all petrol. War correspondent Alan Moorehead wrote, with dry understatement:

“We could put a couple of petrol cans in the back of a truck. Two hours of bumping over desert rocks usually produced a suspicious smell.”

The “cans” were the problem.

Thin tinplate, four-gallon containers with soldered seams. Soldiers called them “flimsies” for a reason. Stack them, they buckled. Drop them, they split. Heat them, the seams gave way and fuel seeped out in a steady, invisible trickle. Packed two to a wooden crate, then cheaper plywood, then cardboard, they were effectively single-use. Once emptied, they were trash.

Daniel watched fuel soak into the sand in a thousand quiet accidents. He watched men fight with screw caps, cork gaskets, funnels, wrenches—equipment designed for static depots, not mechanized war in a trackless desert. He sent a cable back to Washington estimating 40 percent losses. Years later, he’d admit he’d chosen the number to shock the bureaucracy awake. The real figures weren’t much kinder.

British commander Sir Archibald Wavell had guessed 30 percent losses. In one documented case, 70,000 imperial gallons left a depot. 30,000 arrived. A 57 percent loss.

The quartermaster on site still called it “good.” He’d seen worse.

While Allied fuel evaporated, leaked, or sloshed into the sand, the Germans seemed to have found a way to make fuel containers that simply… worked.

Allied troops first got a good look at them at Benghazi.

After the second capture of the Libyan port in late 1941, British and Commonwealth troops found pallets of squat, green cans scattered through Axis dumps. They looked almost new despite months in the desert. Men quickly discovered they didn’t leak, stacked beautifully, and poured smoothly.

They started hoarding them.

The Long Range Desert Group, those masters of deep penetration raids, switched entirely from British flimsies to captured German cans by early 1942. To them, jerry cans were almost as valuable as captured vehicles.

The formal German name was Wehrmacht Einheitskanister—Armed Forces Standardized Can. It had been born not in the desert, but in an engineering office in Schwelm, Westphalia.

In 1937, engineer Vinzenz Grünvogel at Müller Engineering Works responded to a call by the Wehrmacht for a standard “unit canister.” Field trials had begun as early as 1936; a test batch of 5,000 cans went to troops. On 8 July 1937, after three years of refinement, the German Army formally adopted it in order AHM 324.

By the time war broke out, Germany had stockpiled thousands.

Motorized units received not just cans, but rubber hose for siphoning fuel from any tank, truck, or depot they stumbled across. That little detail would help Panzers outrun their supply lines in Poland and France.

The design looked simple. It wasn’t.

Twenty liters—roughly 5.3 U.S. gallons—held between two pressed steel shells welded together. Across both faces, a recessed “X” indentation zigzagged, like a stamped signature.

That X wasn’t decoration. It was structure and physics: four stiff triangular panels where there would otherwise be thin, weak sheet. A flex zone for expansion and contraction. Gasoline expands a few percent when heated; the X bowed outward under heat and snapped back when cooled. No bulging, no split seams.

Inside, a protective coating guarded against corrosion.

On top, three handles: two short ones at the sides, one long across the middle. The Wehrmacht had written it into the spec: a soldier must be able to carry two full cans or four empties. The triple handle layout allowed one soldier to carry two, one in each hand, or two men to pass cans down a line, hand-to-hand, in a tight chain.

The cap was genius in its own right. No threaded lid with a cork gasket, no wrench. A cam lever clamp, with an internal breather tube. Flip it, pressure equalized, fuel poured in a smooth, glug-free stream. One man could empty the can into a vehicle in seconds, no funnel needed. A small air pocket in the top even let the can float if it fell into water.

Everything was recessed—handles, seams, cap—so the cans could be stacked tight without knocking off fittings. Everything had been field-tested and refined before the war.

The Germans classified the design. They filed the patent in 1939, but kept the details from public view. They didn’t want anyone copying the invisible tricks that made the can work.

But someone noticed anyway.

In 1939, a curious chain of events pulled the jerry can out of secrecy and onto Allied desks.

American engineer Paul Pleiss had built a vehicle to drive to India with a German friend. When they finished the car, they realized they had no good way to carry enough emergency water.

The German had access to a stockpile of the new canisters at Tempelhof Airport in Berlin.

He procured three.

Pleiss was impressed enough to ask for the specs. According to his later account, he brought one can and its measurements back to the United States. He walked it around to military offices, trying to get someone interested.

Without a sample, no one listened.

Eventually, by a circuitous route, the car—and one of the cans—arrived in New York. A sample jerry can made its way to the Quartermaster General’s office in Washington in the summer of 1940. Later that year, Pleiss, in London, was asked about the cans by British officers. He had his second can flown over.

The design was now in Allied hands.

And then… nothing happened.

The U.S. Army initially rejected it. There’s no clean paperwork explanation. Maybe “not invented here” bias. Maybe fears about welding complexity. Maybe simple bureaucratic inertia.

Instead, the War Department chose to keep using existing World War I-era ten-gallon cans with screw tops and spanners. In the meantime, the British kept using flimsies.

Eventually, someone at Camp Holabird, Maryland—Quartermaster Corps’ research and development branch—took a serious look. Engineers there measured every curve and angle, photographed each feature, cut cans open, read the steel.

Then they did what engineers are almost hard-wired to do.

They tweaked it.

The American version that emerged from Holabird in 1940–41 looked very much like the German original. Same roughly 20-liter capacity. Same outline. Triple handles. Cam-lock lid. The X stayed, although slightly simplified. On the outside, a jerry can was a jerry can.

The crucial change was where nobody on a staff tour would see it.

The Germans welded their seams.

Two halves, resistance-welded along the edge, the bead nestled in a recess, strong and continuous. It took good equipment and skilled operators.

The Americans decided to roll theirs.

They folded the edges together and crimped them—a rolled seam. It was faster, needed less specialized gear, used less steel. On paper, more efficient.

The U.S. can was also slightly lighter: about ten pounds compared to the German eleven and a half. For water and non-volatile liquids, those rolled seams worked well enough.

For gasoline in desert heat, they were a bad joke.

Daniel, watching fuel seep into Egyptian sand in 1942, would later write with professional irritation:

“As any petroleum engineer knows, it is unsafe to store gasoline in a container with rolled seams.”

Metal flexes. Daytime temperatures in the desert climbed above 120°F. At night, they could drop 40 or 50 degrees. The steel expanded and contracted, again and again. The crimped joints flexed microscopically.

Tiny gaps opened.

Not dramatic sprays. Just a wet shine along the seam. A dark ring on the sand. A smell that clung to everything.

Multiply that by thousands of cans, loaded on trucks that bounced for miles. The leaks became rivers.

Some American variants also dropped or simplified the internal breather tube. Many lacked the careful interior lining. All kept the convenient handles and silhouette.

They had copied the form.

They had quietly altered the function.

By late 1941 and into 1942, American-made jerry cans began arriving in North Africa alongside British flimsies. Allied logisticians, desperate for any improvement, sorted their containers into a crude hierarchy:

Captured German cans: gold standard. Save for critical missions.

American rolled-seam cans: better than flimsies, but not by much. Use for less critical storage.

British flimsies: last resort.

The rolled seam failed in exactly the way the soldered seam failed, just more slowly. Heat cycles, rough handling, expansion—tiny leaks, big losses.

Daniel’s alarmed cable in September 1942 finally pushed the problem up the priority ladder. The War Department couldn’t ignore it anymore. Tanks were literally stopping in the desert for lack of fuel that technically, on paper, had already been delivered.

Still, the American answer wasn’t to shut down its flawed production and retool.

It was to let the British fix it.

British factories, by 1943, began mass-producing their own jerry cans. Not modified. Not simplified.

Copied.

Welded seams. Proper breather tubes. Interior coatings. Faithful reproductions of the German originals.

By early 1943, two million British-made jerry cans were in North Africa. By 1944, Middle Eastern plants were stamping them out as well. Millions more followed for Italy and Northwest Europe.

They worked. They didn’t leak. They survived heat, cold, rough treatment, and stacking. For every Allied unit that could get them, the fuel crisis eased.

American factories kept right on making rolled-seam cans at the same time.

Even in Europe, with shorter supply lines and milder temperatures, the effects lingered.

Fuel represented about half of all Allied supply tonnage by weight. A standard U.S. 2½-ton truck could carry about 875 gallons of fuel in jerry cans. That fuel meant movement, artillery fire, air operations.

In August 1944, during the pursuit across France, the limiting factor for fuel delivery wasn’t petroleum in depots.

It was cans.

There weren’t enough durable containers forward to physically move the fuel to the front. Patton’s famed Third Army—slicing across France, outrunning maps—screeched to a halt near Metz in early September. Weather and German resistance played their part. So did the logistics system that could flood Cherbourg with fuel but couldn’t move it quickly enough inland.

By October, U.S. records show 3.5 million jerry cans “unaccounted for” in the European Theater. Many hadn’t disappeared. They’d simply… stopped being fuel cans.

Troops had used them to pave walkways over mud. As improvised chairs. As trash containers. As barricades. Others sat in abandoned dumps, scattered from Normandy to the German border.

Quartermaster Corps analysts concluded they didn’t need 800,000 new cans a month, as previously thought.

They needed 1.3 million.

By VE Day, U.S. forces in Europe required some nineteen million jerry cans to keep moving. Total Allied production reached over twenty-one million of various designs.

President Franklin Roosevelt, in November 1944, remarked:

“Without these cans, it would have been impossible for our armies to cut their way across France at a lightning pace.”

He was talking about the cans that worked—the German originals and the British welded copies.

Not the rolled-seam American version that had bled fuel into sand two years earlier.

The exact number of gallons lost specifically because of American rolled seams will probably never be known.

Daniel, in his 1987 article “The Little Can That Could,” noted that little about the jerry can made it into formal records. The same bureaucracy that ignored the design in 1940 wasn’t eager to document its own mistake in 1942.

But the outlines are clear.

Severe fuel losses in 1942–43. German containers far superior in field conditions. British industry stepping in to manufacture proper welded cans in 1943. A gradual improvement in Allied fuel handling as the good design displaced the bad.

The German can worked because every detail had been treated as non-negotiable. Welded seams. Recessed X. Breather tube. Interior lining. Three handles. Recessed cap. All of it had been tested under real conditions, refined, and locked down.

American engineers kept what they could see and simplified what they thought they could get away with.

The seams were invisible—until they weren’t.

After the war, when there was time to think instead of just react, NATO standardized on its own 20-liter fuel container. Its silhouette is instantly recognizable. Welded seams. Triple handles. X pressed into the sides.

Technically, it’s described in dry documents like MIL-C-53109 and later MIL-PRF-32269. Practically, it’s the 1937 German design with a few tweaks, adopted because, in the field, nothing fundamental needed fixing.

Nearly ninety years after Vinzenz Grünvogel drew the first sketches, jerry cans are still in use worldwide. On military bases. In humanitarian relief convoys. On the backs of expedition vehicles.

The rolled-seam U.S. cans are gone—relegated to collectors and museum shelves as artifacts of a lesson learned the hard way.

The lesson is simple:

Details matter.

Invisible engineering choices—how a seam is joined, how a lid vents air, how a panel flexes under heat—can decide whether 70,000 gallons of fuel become 70,000 or 30,000 where they’re needed most.

Copying the shape of a successful design while changing the parts you don’t understand is not innovation.

It’s sabotage by ignorance.

In wartime, that ignorance is measured in stalled tanks, delayed offensives, and fuel soaking silently into sand.