Motor Torpedo Boat

MTBs on their way back from Anti-E-boat Patrol

Motor Torpedo Boat (MTB) was the name given to fast torpedo boats by the Royal Navy, the Royal Canadian Navy and the United States Navy.

The capitalised term is generally used for the Royal Navy (RN) boats and abbreviated to MTB. During World War II the US Navy boats were usually called by their hull classification symbol of "PT" (from Patrol, Torpedo) and are covered under PT boat though the class type was still "motor torpedo boat". German motor torpedo boats of World War II were called S-Boote (Schnellboote German for "fast boats") by the Kriegsmarine and E-boats by the allies. Italian MTBs of this period were known as "Motoscafo Armato Silurante (MAS) translating as "torpedo armed motorboats".

History

MTB in the Mediterranean.

MTBs were designed for high speed and manoeuvrability on the water to get close enough to launch their torpedoes at enemy vessels. With next to no armour, the boats relied upon 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 World War I. Italian MTBs were called MAS boats and were comparatively small, at 20-30 tons displacement. MAS 15 was the only Motor Torpedo boat in History to sink a battleship, the Austrian Szent István in 1918.

British torpedo boats of the First World War were small at only around 15 tons and were known as Coastal Motor Boats.

In the Second World War, British MTBs were operated by Royal Navy Coastal Forces.

A similar size boat with a different role of the Second World War was the BPB 63 ft High Speed Launch used by the RAF.

The last MTBs for the Royal Navy were the two Brave class fast patrol boats of 1958 which were capable of 50 knots (93 km/h).

Notable operations

• Dunkirk evacuation
• Channel Dash
• St. Nazaire Raid
• Operation Neptune

This section requires expansion.

Specification

Many boats were built with the MTB designation.

Vosper Private Venture Boat

Designed by Commander Peter Du Cane CBE, the Managing Director of Vosper Ltd, in 1936. She was completed and launched in 1937, she was bought by the Admiralty and taken into service with the Royal Navy as MTB 102.

• Length: 68 ft (21 m)
• Beam: 14 ft 9 in
• Draft: 3 ft 9 in
• Powerplant: 3 Isotta Fraschini 57-litre petrol engines
• Power: 3,300 hp.
• Speed 48 knots (light), 43 knots (loaded and armed)
• Crew: 2 officers, 10 men.
• Armament:
  • Two 21-inch (533 mm) torpedo tubes (depth-charges, machine guns and the Swiss made Oerlikon 20 mm cannon were trialled on her)

MTB 102 was the fastest wartime British naval vessel in service. She was at Dunkirk for the evacuation and carried Winston Churchill and Dwight Eisenhower to review the fleet for the Invasion of Normandy.

British Power Boat 60 ft MTB

Based on the British Power Boat rescue boat for the Royal Air Force but reduced to 60 ft in length. It could carry two 18 inch torpedoes at a maximum speed of 33 knots. The Royal Navy ordered their first in 1936; with a total of 18 ordered. These entered service as MTB Numbers 1 to 12 and 14 to 19.

Vosper 70 ft Motor Torpedo Boat

Although various boat lengths were produced by Vosper for the Royal Navy, the "70 ft" was produced from 1940. The design was produced with modifications as MTBs 31-40, 57-66, 73-98, 222-245, 347-362, 380-395 and 523-537.

On 3 Packard marine engines, they were capable of around 37 knots. Early models carried two 21-inch torpedo tubes, two 0.50 in machine guns and two 0.303 in machine guns. They could also carry four depth charges.

Vosper Types 1 & 2

Between 1943 and 1945 two Vosper designs appeared, the "Vosper Type I 73ft", and then the Type II

Vosper Type I

• Length: 73 ft (22 m)
• Engine: 3 Packard 12M engines for a total of 4,200 hp
• Speed: 40 knots (74 km/h)
• Range: 470 nmi (870 km) at 20 knots (37 km/h)
• Displacement: 47 t
• Armament:
  • Four 18-inch (457 mm) Torpedo tubes
  • Oerlikon 20 mm cannon
  • Two 0.303 in Vickers K machine guns (optionally two 0.5 Vickers MG)
• Crew: 13

Vosper Type II

This design remained in use after the war.

• Length 73 ft (22 m)
• Engine 4,200 hp
• Speed 40 knots (74 km/h)
• Range 480 nmi (890 km) at 20 knots (37 km/h)
• Displacement 49 t
• Armament
  • Two 18-inch (457 mm) Torpedo
  • QF 6 pdr Mark IIA (57 mm)^[1]
  • 20mm Oerlikon
  • Two 0.303 Vickers MG
• Crew 13

RCN MTB

These where used by the Royal Canadian Navy 29th MTB Flotilla. Originally designed as Motor Gun Boats (MGBs) carrying a 6-pounder (57 mm, 2.24 inch) to engage enemy small craft they were redesignated as Motor Torpedo Boats.

Scott-Paine Type G 70 foot boat.

• Manufacturer: British Power Boats, Hythe
• Displacement: 55 tons
• Overall length: 72 ft 6 inches (21 m)
• Breadth: 20 ft 7 inches (6.3 m)
• Draught: 5 ft 8 inches (1.7 m)
• Maximum speed: 38 to 41 knots (new)
• Armament:
  • auto-loading 6 pounder gun (57 mm, 2.24 inch)
  • Two 21-inch (530 mm) torpedo tubes
  • .303 or .50 Vickers machine guns
  • 20 mm Oerlikon or 40 mm Bofors cannon
• Powerplant - three Rolls-Royce or Packard 14M supercharged V-12 (three shafts)
• Power - 3,750 hp total
• Range - 140 miles (260 km) at 25 knots (46 km/h)
• Crew -

See also

• Motor Launch
• Motor Gun Boat
• Fairmile D motor torpedo boat - British "Dog Boats"
• German torpedoboats of World War II
• Fast Attack Craft
• Coastal Forces of the Royal Navy

Notes

References

• British Motor Torpedo Boat 1939–45 by Angus Konstam, Osprey, 2003, ISBN 1-84176-500-7
• Dog Boats at War: A History of the Operations of the Royal Navy d Class Fairmile Motor Torpedo Boats and Motor Gunboats 1939-1945 by L. C. Reynolds and Lord Lewin, Sutton Pubns Inc, 2000, ISBN 0-7509-2454-3

External links

• A Short History of HMS St Christopher
• http://www.bmpt.org.uk/index.htm - British Military Powerboat Trust