At the outbreak of WII engineering company Holman Brothers Limited invented a curious way of dealing with enemy aircraft: the Holman Projector

Across Britain during the Second World War, in government factories, industrial workshops, even garden sheds, all kinds of new weapons were hurriedly developed. Some worked well; others proved more dangerous to their operators than the foe. In Cornwall, the old-established engineering company Holman Brothers Limited invented a curious way of dealing with enemy aircraft: the Holman Projector.

Based in Camborne, Holmans was a world-renowned supplier of compressed air tools, many used by the mining industry; the company had no background in modern weaponry. Undeterred though, within a fortnight of the war’s outbreak a prototype Projector had taken shape, drawn up by director Treve Holman.

A pneumatic mortar, the device consisted of an upward-pointing steel pipe with a simple sighting mechanism, mounted on a hefty metal baseplate. Ammunition was made from hand-grenades wedged in small metal canisters, dropped down the pipe by the Projector’s operator. On striking the pipe’s bottom, compressed air would fling the bomb skyward where it would devastate the enemy’s aerial fleets. That was the theory.

In February 1940 the first Projector was tested on sands near the Victory Inn at Porthtowan, firing its ammunition over 600 feet into the blue. But at Portsmouth naval base for more trials, things started badly. The operator dropped his first bomb down the Projector’s barrel but rather than hurtling aloft, it flopped to the ground just a few feet away. Holman’s boffins and distinguished Navy observers flung themselves down, but nothing happened. Investigations revealed the round was a dummy, used by mistake and without the weight to actuate the Projector properly.

Later tests went better, though not without hiccups. In June 1940 Prime Minister Winston Churchill arrived to witness the trials, but a snag emerged when it was found neither Holmans nor the army had remembered to bring any ammunition. With true British improvisation though some beer bottles were used, substitutes which showed the Projector’s principles as they sailed through the air, leading Churchill to remark cheerfully that the device would “save on cordite.”

At that time there was a desperate shortage of weapons to help defend Britain’s shipping from enemy attack. The Projector quickly entered production in Holman’s works, and a training school opened at Camborne. From as far as Scotland, ratings arrived for a week's course on using and maintaining the apparatus. Thousands of Projectors were fitted on trawlers and merchant ships, minesweepers and destroyers; even the Scillonian passenger ferry between Penzance and the Isles of Scilly received one.

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Later versions of the Projector abandoned the muzzle-loading method and were given a firing trigger. The Navy also asked if Holmans could convert the Projector’s compressed air system to steam, so that its power could be drawn from ships’ steam lines. But Treve Holman was worried the change might affect his weapon’s bombs; with a test in mind, he telephoned Cornwall County Council.

At the beach by Porthtowan, a Council steamroller duly arrived and was connected to a loaded Projector. Its steam pressure was raised; from a distance everyone watched anxiously, while for 20 minutes the bomb was cooked. It suffered no ill-effect from its ordeal, and Holmans successfully introduced the modification.

Unsurprisingly though, since the enemy generally flew well above the greatest height its bombs could reach, the Projector became more a deterrent than a lethal weapon of war. But one odd characteristic was certainly of use; the bombs burst with a great puff of black smoke, a peculiarity not seen with grenades at ground-level. Sometimes the blasts deceived enemy pilots into believing ships’ defences were deadlier than was actually the case, and the German flyers would leave in search of softer targets.

How much did Projectors contribute to seeing off enemy aircraft? Old company papers tell us they were used in numerous actions at sea during which German aeroplanes came down. Usually though, ships fired their Projectors along with other weapons of much greater range and efficiency.

One successful engagement took place off Aberdeen in August 1940, when the small coaster SS Highlander (Captain William Gifford) was attacked just before midnight by three low-flying German floatplanes. The Highlander had only a stern machine-gun and a Projector on the foc’s’le, yet in the exchange two aircraft crashed, one hitting the vessel’s poop. The Projector’s operators were the only ship’s crew injured and Highlander reached port safely. Fireman Bert Whyman and Able Seaman George Anderson, in charge of the Projector, received the British Empire Medal.

But Holman’s device had always been seen as a stop-gap; when better anti-aircraft measures came along, it was taken out of service. Generally the Projectors were discarded or reduced-to-produce’, melted down to make other items. Fortunately though, that wasn’t the end of the story for today, two of these unique weapons survive at King Edward Mine Museum at Troon, near Camborne.

Gerald Bodilly and Frank Kneebone are volunteers with the museum; both retired, they now help keep the exhibits pristine and have a great understanding of the Projector. Gerald admires its simplicity: “It was a practical weapon, easy to manufacture, and used only materials in ready supply: cast iron and mild steel. Projectors were straightforward to operate and ideal for merchant seaman, who weren’t used to handling explosives.”

Surprisingly the weapon also had its amusing side, as Frank explains. “Since the barrels were smooth-bore, you could stuff anything down them. At sea, ships’ crews would sometimes use their Projectors to fling potatoes through the air for fun, or stage light-hearted battles’ by hurling water-filled cans at neighbouring vessels.”

The museum has two Projectors; its intact example was rescued from Holman’s old museum in Camborne, now no more. Even today the weapon is menacing, its cold grey muzzle searching skyward, with arcane controls of heavy pipes and levers. “We’re really lucky to have saved it for future generations to view,” reflects Gerald. But more poignant is the other exhibit, a battered relic shot up in action and returned to Holmans in war-damaged state. It’s the Projector which brought down a Heinkel floatplane onto the little Highlander, more than 70 years ago.

To see the last surviving Holman Projectors, visit the King Edward Mine Museum at Troon, Camborne, TR14 9DP.