The Worst Tank Ever is Clearly Not the M1 Abrams or T-14 Armata – Picture a small Caterpillar tractor. Then throw some thin corrugated steel around the vehicle and give it six light machine guns. Oh, and don’t use blueprints, just start building. What emerged from these ramshackle plans was the worst tank in history.

I’m talking about New Zealand’s Bob Semple Tractor Tank that gave new meaning to “hell on wheels.”

Bob Semple Tractor Tank: The History 

During World War Two, New Zealand was scared. The Japanese might invade at any time and there was no main battle tank in the Kiwi arsenal. They had only six Carden-Loyd tankettes. These were machine gun transporters which were an early version of light armored personnel carriers, hardly sufficient to fight off the Japanese.

Enter Robert Semple

Bob Semple was an eccentric and opinionated New Zealander. He was an effective public speaker but lent his talents to Quixotic causes. For example, he was against New Zealand entering World War One and was not in favor of the draft. So much that he lied to a draft board about his son’s age so he could avoid service. Semple was arrested for that and was in legal jeopardy again for leading a miner’s strike against conscription.

Ironically, when World War Two came around, Semple was appointed to a position in government that resembled the Minster of Defense. Remarkably, Semple was put in charge of the draft and this time he was all in for conscription.

Here Comes His Tank

Semple started with the American medium track-type Caterpillar D8. This made sense because New Zealand had about 100 of these already. Semple thought about getting blueprints from the United States so he would have some semblance of a plan, but time was of the essence, and the New Zealanders quickly developed a prototype without blueprints.

The base tractor of the new “tank” first needed some platform adjustments. Designers made the tracks longer. They improved the driver controls and updated the gearbox. They didn’t have anything resembling armored plating, so they decided to go with corrugated manganese plate to surround the tractor.

Just Machine Guns Only

There was no heavy gun, therefore, they put six Bren light machine guns around the box. The tankette could only push out 127 horsepower with its six-cylinder diesel engine for a snail-like pace of eight miles per hour. Surprisingly, the designers wanted to put eight soldiers inside to man all the machine guns and drive it. One crewman even laid on a mattress on the engine to fire his machine gun.

By 1941, New Zealand had two Semple tankettes. Semple and the designers were so happy they sent the models to a military parade thinking the public would love it. Instead, the media had a field day making fun of the boxy-tracked vehicle.

Bob Semple Tractor Tank Was a Disaster

Media relations were the least of its problems. It tipped over when driving over ditches. The guns jammed due to the vibrations, and it couldn’t fire on the move. They had to stop the tank to switch gears. The turret didn’t have a hatch making it difficult for the crew to escape if the boxy vehicle caught on fire.

Despite all the flaws, Semple delivered the two vehicles to the army, so you could say he accomplished his goal of placing them in the military’s hands. The army quickly balked at their offensive capabilities and simply assigned them to guard beaches for an invasion that never came.

It takes one glance at this aberration to determine it has to be the worst tank in history. Semple will go down in history as an armored designer who was better fitted for sitting in an office and doing administrative work instead of creating tanks.

About the Author 

Brent M. Eastwood, PhD, is the author of Humans, Machines, and Data: Future Trends in Warfare. He is an Emerging Threats expert and former U.S. Army Infantry officer. You can follow him on Twitter @BMEastwood.