 However, the London Naval Treaty after World War I limited tonnage of warships, but placed no limits on ships of under 600 tons.The French, Italian, Japanese and German Navies developed torpedo boats around that displacement, 70 to 100 m long, armed with two or three guns of around 100 mm (4 in) and torpedo launchers.For example, the Royal Norwegian Navy s were in fact of a torpedo boat size, while the Italian s were closer in size to a destroyer escort.