Besides having the least-threatening name ever bestowed upon a tank, the Bob Semple barely qualified as one. It was little more than a farm tractor -- and due to several design flaws, it was about as useful as one in a war zone.
The designers based it on an American tractor tank, but the problem was that they had no blueprints, no building materials outside those found in a farm and no idea what the hell they were doing. They literally designed the Bob Semple by looking at a postcard of the original tank. By that logic, half of us should be able to reconstruct the Eiffel Tower.
Via National Library of New Zealand
Also, apparently some of the workers were under the impression that they were building a small house.
The tank was made by placing an armored box on top of a tractor -- and by "armored" we mean "made from roofing material." Supposedly, the corrugated surface would deflect bullets by virtue of its curviness. Since they also lacked artillery in any numbers, they outfitted the Bob Semple with as many machine guns as it could hold. Six to be exact.
Unfortunately, that last part meant having to cram at least six people into that piece of junk. One of the machine gunners had to lie on a mattress in the belly of the tank, right on top of the burning hot engine. The other five had to stand on the first one's back, presumably. And then they needed someone else to drive the damn thing. According to Wikipedia, the total crew consisted of eight people.
In other words, New Zealand had all the military acumen of Hobbiton.