Did you know the Italians put a flamethrower on a submarine in World War II?

If there are two pieces of military equipment you wouldn’t think go well together, it must be submarines and flamethrowers. How are you going to set anything on fire underwater? Or, if you have a surface target, why would you use short-range flames which do not damage a steel hull when you could just use your deck gun at a far longer range?

And yet, the Italians did marry the two technologies – at least experimentally.

Italy’s four Gofredo Maneli class submarines were built and commissioned in the 1920s. They played a minor role in the Spanish Civil War, clandestinely supporting the Nationalist side. In 1938, they underwent technological evaluation at the port of Taranto, the later site of an innovative British attack in what became the “prototype” of Pearl Harbor. (The Pioneering Attack on Taranto)

Two of the submarines, the Tito Speri and the Giovanni da Procida, were equipped with the so-called Girosi device, named after its inventor, at this time. The device was a flamethrower mounted on top of the periscope so it could be remotely activated when the boat was at periscope depth. The one photo we could find of it, shown at the beginning of this article, depicts the flame being pointed at the sky, but this was not the intended use. The submerged vessels were supposed to release some of their fuel into the water, then rise to periscope depth and fire the flamethrower downwards, into the oil slick, setting it on fire. 

This was supposed to be done at the entrance of an enemy-held harbor, creating a brief but intimidating wall of flame which would confuse and terrify crews while constraining ship movement, allowing the submarine to hit its targets more easily (with its conventional weaponry). 

Some sources claim over 20 Italian submarines were equipped with the Girosi device, but there are no records of it ever having been actually used. While the idea was certainly imaginative, it ended up in the pile of innovations that failed to pan out in the war. 

You can learn more about Italian weapons and inventions on our Italian Campaign Tours while you enjoy the exquisite Italian meals and cultural highlights.