This Bofors 40 mm anti-aircraft cannon is one of the most extraordinary exhibits at the Anti-Aircraft Museum. There is nothing extraordinay in the cannon itself; it is an ordinary 40 mm Bofors anti-aircraft cannon from 1939, but how it ended up in Finland is still a mystery. Enquiries have been made with experts, including curators of the Imperial War Museum, but the origin of the cannon is still shrouded in obscurity.

The cannon was manufactured for the British Armed Forces in 1939. We know that manually-controlled single-mount versions were made for the smaller vessels in the British Navy, while aircraft carriers and cruisers were armed with Bofors mechanical-electric automatic cannons, or alternatively, twin-mount or quadruple-mount versions. It is also possible that this cannon is one of about 180 original Bofors cannons delivered from Sweden in 1939, later modified by the Germans or the British to fit a fixed artillery platform. Both options are plausible, as pictorial evidence suggests that the cannon mount includes features of both a British fixed mount and a movable mount. In addition, historical literature tells us that Nuffield Factories carried out experimentation at the beginning of the war to accelerate the mass production of Bofors parts. It is also possible that the cannon and the mount do not come from the same weapon. Finnish sights and safety markings have been added to the weapon, possibly in the 1960s.

According to some information, the cannon had arrived in Finland onboard the German anti-aircraft ship Niobe (formerly HNLMS Gelderland), but this is not certain. However, photographs of the era do show 40 mm Bofors cannons on the deck of Niobe. The Germans could have taken the cannon from the British Navy or ground forces either in Dunkirk or Egypt or during the Norwegian campaign. Niobe sank in the port of Kotka in July 1944, so the cannon could have fallen into Finnish hands between 1944 and 1953. The sunken Niobe was raised for scrapping in 1953. Another explanation is that the cannon is from Belgium, where it was captured when the Wehrmacht attacked in 1940. During the Continuation War, Finland procured many cannons from Germany, which the Germans had taken from their enemies.

References: Gander, Terry J., The Bofors Gun Bofors Ordnance AB /Patrick Stephens Ltd. Colchester 1986, http://www.bellabs.ru/51/Photos/_Attack.html#Niobe (visited on 14 Oct 2020)