Motor gunboat

MGB 314,aFairmile C motor gun boat,duringWorld War II

Themotor gunboat(MGB) was a small, high-speed British military vessel of theSecond World War,which was armed with a mix of guns, in contrast to the physically similarmotor torpedo boat(MTB), whose main offensive weapon weretorpedoes.The small size of the MGBs, and their high speed, made them difficult targets for GermanE-boats,though, like their opponents, they were limited by heavy weather, because they did not provide a stable-enough platform to aim the guns.The large number of guns meant the crew was relatively large, numbering as high as thirty men on the largest boats.

Description

MGBs were extremely heavily armed for vessels of their size. Early MGBs were, nevertheless, small boats, being based on Motor Anti-Submarine Boats of 63–70 feet in length; these would later be considered 'short' boats by Coastal Forces. These were mostly equipped with one heavy weapon and numerous lighter guns. The later 71.5-foot short MGBs would sport two heavy weapon locations (a pom-pom forward and twin Oerlikon aft), outmatching contemporary enemy boats of larger size. The outstanding feature of most short MGBs was their very high speed of 36–40 knots, enabling them to work with, or in place of, MTBs on offensive sweeps.

From June 1941, the Fairmile Type 'C' MGB began to join Coastal Forces; this boat was based on the earlier Type 'A' Motor launch and was the first of the 'long boats', being 110 feet long. A major feature of the long MGBs was that they carried two heavy guns as well as numerous lighter weapons; the 27-knot Type 'C' began to introduce the versatile & hard-hitting Vickers pom-pom to Coastal Forces' inventory, as well as carrying one of the ubiquitous 2-pdr Rolls guns on the aft bandstand.

In March 1942, the first of the Fairmile 'D's joined the MGB force, this type becoming the main long MGB for the remainder of the conflict. These had room for an even heavier armament than the Type 'C' and the weight of armament was incrementally improved as the war went on. early models had as little as one powered pom-pom mount forward, twin powered 20mm aft and two twin HMGs by the bridge plus LMGs, but more often placed the 20mm twin mount amidships and added a QF 6-pdr gun aft. By 1945,MGB 658carried two power-mountedQF 6-poundersin the A and Y turret positions, a twin 20 mmOerlikon cannonin the X turret position, a single 20 mm Oerlikon on either side forward of the bridge, and two twin.303Vickers machine gunson the bridge wings. They were also equipped with smoke-making equipment, basicradaranddepth charges.

Service

MGB 66at speed with the crew at action stations, off the coast of Scotland

In the early years of the war, MGBs saw action defending shipping against enemy torpedo boats, such as theGermanE-boats,on the southern and eastern coasts of the UK, with the faster 'short' boats frequently undertaking patrols hunting for the enemy. MGB flotillas (particularly underRobert Hichens' command) also developed the tactic of accompanying MTBs on their patrols across the North Sea to attack enemy coastal shipping. On these missions, the MGBs' role was to close stealthily with the enemy and then attack with guns from an unexpected quarter, drawing the convoy escort's attention, while the MTBs manoeuvred into position unseen by the Germans, so as to better attack the protected convoy shipping with their torpedoes.

The modest speed of the larger & heavier Type 'C' compared with the short boats saw them assigned much more frequently to defensive & convoy escort duties as well as clandestine work. The latter duties often involved extraction of Allied agents/escapees from occupied France but also included the commando raid 'Operation Chariot':Robert Ryderused a Type 'C' MGB for command of theSt Nazaire Raid.Ryder andWilliam Savage,the gunner of the unprotected two-pounder gun on MGB 314, receivedVictoria Crossesfor their part in the raid, Savage posthumously.

In theMediterranean,MGBs were used in an attacking role to sink Italian and German shipping. They were formed into flotillas which often operated alongsidemotor torpedo boats(or USPT boats)and helpedinterdictsupplies being sent fromItalyto Axis forces inNorth Africain 1943. After that campaign, they moved northwards and assisted with theinvasion of Sicily,Sardinia,CorsicaandElba. Operating from island bases they patrolled along the western coast ofItaly,attacking small coastal ships and E-boats until mid-1944. As Italy was progressively liberated, certain flotillas, such as the 56th, were sent around Italy to theAdriaticto assistpartisansin the islands offYugoslavia.

MGBs were also involved in the protection of shipping afterD-Day.

MGBs did not take the prefixHMSas they were boats, not ships, and instead used the prefix "HMMGB" on formal occasions. The crews generally referred to them by their numbers.

In 1947,MGB 2009was fitted with aMetrovickgas turbine, thereby becoming the world's firstgas turbinepowered naval vessel.

Types

Thegas turbinefromMGB 2009(formerlyMGB 509)

British Power Boats

Early-war motor anti-submarine boats (MA/SBs) built by BPB Co. were converted from early 1941 into MGBs. These included 63-foot and 70-foot types.

63-foot MGBs (numbered40–45) were of 24 t std displacement and powered by 2-shaft Rolls-Royce petrol engines developing 2,200bhpfor a top speed of 40 knots. They were rearmed for the MGB role with 1 × 20 mm Oerlikon aft (some may have briefly carried a Rolls gun until the Oerlikon was available), a twin HMG turret on the coach-house roof and 2-4 ×.303-inch MGs (two twin mounts would be mounted abreast the wheelhouse).

70-foot MGBs were of several different original batches or types:MGB 6-21originally had 3-shaft Napier petrol engines for 1,650 bhp and a top speed of 27 knots, being later refitted with Packards for 3,600 bhp and 38 kts, whileMGB 46andMGB 50-67had 3-shaft Rolls-Royce installations for 3,300 bhp and a top speed of 36.7 kts. All were of 28–30 t std displacement. Individual armament varied, but most boats had 2 × twin HMG turrets abreast the bridge (some early models had the single dorsal turret seen on the 63-feet type) in the case of ex-French boats likeMGB 66these turrets replaced a pair of twin 0.303-inch turret which had been carried side by side amidships. Heavier gun armament on these boats, located aft, was initially either a 2-pdr 'Rollsgun' or less commonly a Boulton & Paul quad 0.303-inch MG turret. Surviving boats were later rearmed with a far more effective Oerlikon in the aft position.

71+1⁄2ft Motor Gun Boat

BPB built 34 purpose-built 72 ft MGBs (also referred to as 71.5-feet). Capable of 40 knots, they carried a hydraulically powered 2-pounder gun mount forwards for engaging other vessels, along with a twin powered 20mm mount on the aft cabin roof and two twin.303-in machine guns (one either side of the wheelhouse) for additional firepower in surface actions as well as defence from aircraft. Some early boats even carried a Holman Projector right aft. Side-dropping depth charges and smoke generators at the stern completed the loadout.

Over one hundred vessels of this class built, first ones were given identities MGB 74-97The second series were numberedMGB 107-onwards. After the initial 34 MGBs, further craft of the 71.5-feet type (in the sequence up to176and from502onwards) were of a modified type, known as a 'Type G' to the Canadians, and were intended to be MTBs. However, some of the earlier boats in the 'Type G' series were only ever equipped 'for but not with' 18-inch torpedo tubes and otherwise were armed as the original 2-pdr MGB variant, functioning as gunboats in the mixed29th Motor Torpedo Boat Flotillaalongside the torpedo-armed MTB versions from 1944.

Camper and Nicholson

All Camper & Nicholson MGBs were composite-hulled craft.

The entirely gun-armedMGB 502class was preceded by the experimentalMGB 501,which was a unique vessel adapted from a combined MA/SB & MTB design and completed in 1942 as a combined MGB & MTB, with 1 × 2-pdr pom pom, 1 × Oerlikon cannon, 2 × twin 0.5-inch HMGs and 2 × 21-inch torpedo tubes.

The502class were slightly enlarged but otherwise based on the design of501.They dispensed with the torpedo tubes and shipped an armament of 1 ×pom pomin MkXVI mounting, 1 × twinOerlikonin MkV mounting, 2 × twinHMGsand a6-pdrHotchkiss gun. Only502,503and509were completed as MGBs;504-508were completed as fast blockade runnersMaster Standfast,Gay Corsair,Gay Viking,HopewellandNonsuch.

Dimensions for theCamper and Nicholsonmotor gunboats (MGB 502 to MGB 509):

• Length: 117 ft (36 m)
• Beam: 20 ft 3 in (6.17 m)
• Draught: 4 ft 1 in (1.24 m)
• Displacement: 95 tons
• Propulsion: 3 ×PaxmanVRBdiesel engines
• Total power output: 3,000bhp
• Speed:
  • Maximum: 28 knots (52 km/h)
  • Continuous: 25 knots (46 km/h)
• Complement: 21
• Endurance: 2,000 nautical miles (4,000 km) at 11 knots (20 km/h)

MGB 509 was powered by threePackardsupercharged petrol engines giving a total output of 4,050 bhp (3,020 kW) and a maximum speed of 31 knots (27 knots continuous). Later re-numberedMGB 2009,the central engine was replaced with aMetrovick F.2gas turbine engine in 1947.

Elco

Elcobuilt twelve 70 ft (21 m) MGBs for the Royal Navy.

Higgins

Higginsbuilt 12 70 ft (21 m) MGBs and 15 82 ft (25 m) MGBs.

Fairmile designs

Fairmile Marineproduced designs for small craft for the Royal Navy but most construction was carried out in other yards. TheFairmile C motor gun boatswere 110 ft (34 m) long boats.

For flexibility the followingFairmile Ddesign (approx. 200 built) could be fitted out either as MGB or MTB. These equipped the Royal Canadian Navy, Royal Navy, andRoyal Norwegian Navy.

Survivors

MGB 81 at Gosport

The only fully restored and operational example of a Royal Navy Coastal Forces MGB which saw active service in World War II is MGB 81.She was built by theBritish Power Boat Company,Hythe, launched in 1942, and served at the Normandy landings (although renumbered asMTB 416by this time, as the MGB designation had been largely abolished by the RN late in the war). She is now at Portsmouth.MGB 81 is owned and maintained by Portsmouth Naval Base Property Trust

See also

• Motor launch
• Harbour defence motor launch
• Fairmile C motor gunboat
• Steam gun boat
• Motor torpedo boat
• Coastal Forces of the Royal Navy
• Type Two 63 ft HSL
• Robert Peverell Hichens,renowned MGB flotilla commander
• Guy Hamilton,film director who served on MGBs during the war.

References

Bibliography

• Motor Gunboat 658LC Reynolds (Cassell Military Paperbacks, London, 2002)ISBN0-304-36183-6
• Konstam, Angus (2010),British Motor Gun Boat 1939–45,New Vanguard 166, illustrated by Tony Bryan, Osprey,ISBN9781849080774
• Kemp, Paul J (1997),British Coastal Forces of WWII,ISO Publications, London,ISBN0-946784-52-3

External links

• British Military Powerboat Trust
• Whaleback MGB
• The Coastal Forces Heritage TrustArchived20 February 2020 at theWayback Machine
• Official account of MGB and MTB actions in Mediterranean 1943,published 1948
• Database MTB-/MGB-Battles 1940-1945.Historisches Marinearchiv(German/English)