MAS-Boat

This was a slow, quiet, electrically driven boat inspired by the British rhomboid tanks. It combined the flat-bottomed hull of a landing craft with a pair of 45-cm torpedoes in side-dropping gear and two hook-studded, engine-driven chains mounted on either side of the hull. The Grillo could approach boom defenses quietly and clamber over them, much like a tank crushing barbed wire. Once inside the anchorage, it would attack with its torpedoes and retire the way it came. The Grillo was not very successful in action. The chain mechanism produced a frightful clatter that all but negated the advantage of the silent, 15-hp electric motor. They were usually destroyed by shellfire before they got over the booms. Nevertheless, the Austrian navy was interested enough to raise and copy a sunken example.

While the war was raging on the battlefields of Europe, and submarines were terrorising the ships on the high seas, the Austro-Hungarian fleet and Italian fleet lay mostly well protected in their harbours, surrounded by mine-fields and anti-submarine nets. This passivity was, in the main, due to the ongoing submarine war. In 1915, after Italy had severed its connections with its German and Austrian allies, and joined the English-French Alliance, Italian naval officers had thought long and hard about how the Austro-Hungarian fleet could be attacked in the harbour.

The first attempt, carried out from Venice, on 13/14 May 1918, was made by the Italian naval Commander Pellegrine, who, with three other crew members in a motor-boat, tried to attack the Austro-Hungarian fleet in Pola. Pellegine’s boat Grillo was equipped with caterpillar tracks which enabled it to crawl up over the various barriers in Pola. Two torpedoes, which hung on the side of the boat, were to be sent against the ships in the harbour. Pellegrine’s attempt failed because the boat was discovered as it was forcing a barrier. Pellegrine and his crew spent the rest of the war in captivity.