Motor Torpedo Boat

Motor Torpedo Boat (MTB) was the name given to fast torpedo boats by the Royal Navy and the Royal Canadian Navy. The 'motor' in the formal designation, referring to the use of petrol engines, was to distinguish them from the majority of other naval craft that used steam turbines or reciprocating steam engines.

The capitalised term is generally used for the Royal Navy (RN) boats and abbreviated to "MTB". During the Second World War, the US Navy boats were usually called by their hull classification symbol of "PT" (Patrol, Torpedo), and are covered under PT boat although the class type were still "motor torpedo boats".

German motor torpedo boats of the Second World War were called S-boote (Schnellboote, "fast boats") by the Kriegsmarine and "E-boats" by the Allies. Italian MTBs of this period were known as Motoscafo Armato Silurante ("MAS boats", torpedo armed motorboats). French MTBs were known as vedettes lance torpilles ("torpedo-launching fast boats"). Soviet MTBs were known as торпедные катеры (torpedny katery; "torpedo cutters").

After the end of the War in 1945, a number of the Royal Navy's MTBs were stripped and the empty hulls sold for use as houseboats.

MTBs were designed for high speed, operating at night, low speed ambush (to keep noise low and to produce no wake) and manoeuvrability on the water; this was to enable them to get close enough to launch their torpedoes at enemy vessels. With no significant armour, the boats relied upon surprise and their agility at high speed to avoid being hit by gunfire from bigger ships.

The British and Italian navies started developing such vessels in the early 20th century, shortly before the beginning of the First World War. Italian MAS boats were comparatively small, at 20-30 tons displacement. MAS 15 was the only motor torpedo boat in history to sink a battleship, the Austro-Hungarian vessel Szent István in 1918.

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