DIY defence

The Semple tractor tank has a reputation as a homegrown groaner, but was it really such a bad idea?

IN MID-1941, THE CHRISTCHURCH AND DUNEDIN UNIVERSITY STUDENTS HELD THEIR CAPPING PARADES. ALONG WITH THE USUAL MOTLEY, INCLUDING A SIX-LEGGED PANTOMIME HORSE, LOTS OF BOYS IN DRESSES AND A DEVICE CALLED “THE NEW POMME POMME” THAT FIRED APPLES AT THE CROWD, BOTH HAD FLOATS HONOURING NEW ZEALAND’S MOST RECENT FORAY INTO MILITARY HARDWARE: THE SEMPLE TANK. WELL, MAYBE NOT HONOURING. ONE WAS BRANDED THE “SEPTIC TANK”.

The students had a point. The Semple has not fared well in the cold light of historical hindsight, and it was recently called “the least useful tank ever conceived and actually built”. Yeah, nah. I love the Semple Tank, and I am not alone.

The Bob Semple Tank was the brainchild of the honourable Robert Semple, Minister of Public Works for the wartime Labour Government. A former boxer from Crudine Creek, New South Wales, Semple was a militant trade unionist who immigrated to New Zealand in 1904 after being blacklisted back home. Nicknamed “Fighting Bob Semple”, he carried on rabble-rousing in his adopted country, including against conscription in World War I, and even served a 12-month jail stint in 1916. Semple was also a technophile – he saw machines as a liberating force that would free the working class from the shackles of manual toil. To make this point, he once famously drove a bulldozer over a wheelbarrow.

Enter World War II. As 1940 progressed, it became apparent that New Zealand was in a pickle, defence-wise. Britain, otherwise occupied with the fall of France, had made it clear she wouldn’t be sailing south to help us anytime soon, and we faced a growing threat from Imperial Japan.

New Zealand had plenty of soldiers, but modern warfare was more and more about machinery – aeroplanes, ships and tanks – something the Antipodean nations were short of. Semple had strong opinions about this. The British were not coming, and he argued that “instead of sitting around and moaning”, it was time to make do with what we had. The Semple Tank was, at least, something. And what a thing.

Fighting Bob Semple astride a Caterpillar tractor. Ref: 1/2-041944-G. Alexander Turnbull Library, Wellington, New Zealand

Semple’s design revolved around the Caterpillar D8 tractor, a track-based tractor still in use today (for tractoring, that is, not combat). Semple was familiar with the Caterpillar. According to one story, he used his position as Minister of Works to commandeer a couple earmarked for public works to bulldoze a new road down to his own bach at Waikawa Beach.

The first Semple tank prototype came together at the Public Works Department workshop in Temuka in 1940, with two more built in early 1941 at the Railway Workshops in Addington, Christchurch. They weren’t all bad. For one, the kitset concept was brilliant. Unfortunately, the thing had a few shortcomings, and it never got past the prototype stage for a reason.

The Semple had a sluggish top speed of 24 kilometres per hour and, at more than 25 tonnes, was too heavy for most bridges in New Zealand. It would have to ford streams, instead of crossing them. As for use on an actual battlefield, the tank had to be slowed or stopped for gear changes, and it was 4.2 metres tall, which made it both an easy target and alarmingly tippy. The tank was fitted out with six 0.303 calibre Bren machine guns (there were no heavy-calibre anti-tank weapons available in New Zealand, so small arms it was): one poked out from the turret, two faced forward, one protruded from each side, and one pointed backwards.

The crew of eight, as you can imagine, had very little room and, even worse, the all-important forward gunner had to lie on top of the engine, where, after not a significant amount of time, he would start to gently roast.

The Semple’s greatest weakness, however, was telegenic. Take its armour. Nothing says “rural New Zealand” quite like corrugated iron, and the tank’s exterior bore an unfortunate resemblance to the cladding that graces the woolsheds and shearers quarters of our nation.

In fact, the Semple’s outer shell was perfectly decent, and clever. Semple had sourced a supply of made- in-Newcastle military-grade steel that had been shipped to Australia for an Aussie version of the Bren Gun Carrier, but his railway engineers told him it was too flimsy to protect a tank. So, he ordered it cut into strips and welded into a corrugated pattern. Cooke explains this both increased its effective thickness, and protected against small arms fire: “nothing hits a face flat on, so bullets are more likely to be deflected.” As for similarities to corrugated iron, the tank’s corrugations were pointed, not rounded (a cross section would look like a bunch of Ws, not a bunch of Us).

Still, the roofing-ironesque armour gave it a knocked-together-in-a-barn aesthetic that didn’t engender confidence in the populace it was supposed to protect. When the prototypes went on a PR tour in Christchurch, Wellington and Auckland in April and May of 1941, one paper dubbed the tank “Semple’s Pie Cart”, foreshadowing the capping parade parodies to come.

But, had there been an invasion, was it better than nothing? An October 1941 article from the Evening Star quotes Major General Puttick, Chief of the New Zealand General Staff, as calling the Semple “a very impressive job”. After watching off-road trials, he said it might be a useful weapon for certain types of fighting, adding, “I was impressed with the skill and ingenuity displayed by those concerned in the tank’s design and manufacture, adapting a civilian vehicle for military purposes.” Too right, General.

Also, as Cooke points out, although it may have not been the most practical tool in combat, the Semple did help what was a “very neurotic” New Zealand at the time do something palpable for its own defence. As the Auckland Star reported in August of 1941, Semple himself saw the tank as “not a stroke of genius by the Minister of Railways, but of honest effort on the part of the military and the Public Works Department to create something out of material they had at their disposal at the time.”

And let it be noted that, say, compared to the 85,000 Soviet tanks that were destroyed in World War II, not a single Semple was lost. Ok, it was never deployed, but still. (One of the three, the first prototype, did serve in the Pacific, but only after it was reconverted to a bulldozer.)

The Semple Tank says so much about New Zealand’s cultural DNA – its ruralness, its inventiveness, its self-sufficiency – you have to love it at least a little, and, today, many people do, most of them nowhere close to alive in 1940. Thanks to an online renaissance led by tank warfare gamers, the Semple has become a meme. Hey, Fighting Bob, you’re back!

WORDS: LAURA WILLIAMSON

PHOTOS: SUPPLIED BY PETER COOKE

READ MORE ABOUT THE HISTORY OF MILITARY ENGINEERING IN NEW ZEALAND IN WON BY THE SPADE: HOW THE ROYAL NEW ZEALAND ENGINEERS BUILT A NATION BY PETER COOKE (EXISLE PUBLISHING, 2019).