HMS ''G4'' was a

British G-class submarine The Royal Navy's G class of diesel/electric submarines were launched between 1914 and 1917, and intended for operations in the North Sea and German Bight in World War I against German U-boats. Description The G-class submarines were designed by ...

built for the

Royal Navy The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against F ...

during World War I.

Description

The G-class submarines were designed by the

Admiralty Admiralty most often refers to: *Admiralty, Hong Kong * Admiralty (United Kingdom), military department in command of the Royal Navy from 1707 to 1964 *The rank of admiral * Admiralty law Admiralty can also refer to: Buildings *Admiralty, Tr ...

in response to a rumour that the Germans were building

double-hulled A double hull is a ship hull design and construction method where the bottom and sides of the ship have two complete layers of watertight hull surface: one outer layer forming the normal hull of the ship, and a second inner hull which is some dis ...

submarines for overseas duties. The submarines had a length of

overall Overalls, also called bib-and-brace overalls or dungarees, are a type of garment usually used as protective clothing when working. The garments are commonly referred to as a "pair of overalls" by analogy with "pair of trousers". Overalls were ...

, a

beam Beam may refer to: Streams of particles or energy *Light beam, or beam of light, a directional projection of light energy **Laser beam *Particle beam, a stream of charged or neutral particles **Charged particle beam, a spatially localized grou ...

of and a mean

draft Draft, The Draft, or Draught may refer to: Watercraft dimensions * Draft (hull), the distance from waterline to keel of a vessel * Draft (sail), degree of curvature in a sail * Air draft, distance from waterline to the highest point on a vessel ...

of . They displaced on the surface and submerged. The G-class submarines had a crew of 30 officers and ratings. They had a partial double hull.Gardiner & Gray, p. 90 For surface running, the boats were powered by two

Vickers Vickers was a British engineering company that existed from 1828 until 1999. It was formed in Sheffield as a steel foundry by Edward Vickers and his father-in-law, and soon became famous for casting church bells. The company went public in 18 ...

two-stroke A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a Thermodynamic power cycle, power cycle with two strokes (up and down movements) of the piston during one power cycle, this power cycle being comple ...

diesel engine The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-call ...

s, each driving one

propeller shaft A drive shaft, driveshaft, driving shaft, tailshaft (Australian English), propeller shaft (prop shaft), or Cardan shaft (after Girolamo Cardano) is a component for transmitting mechanical power and torque and rotation, usually used to connect ...

. When submerged, each propeller was driven by a

electric motor An electric motor is an Electric machine, electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a Electromagneti ...

. They could reach on the surface and underwater. On the surface, the G class had a range of at . The boats were intended to be armed with one 21-inch (53.3 cm)

torpedo tube A torpedo tube is a cylindrical device for launching torpedoes. There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, and deck-mounted units (also referred to as torpedo launchers) installed aboa ...

in the bow and two 18-inch (45 cm) torpedo tubes on the beam. This was revised, however, while they were under construction, the 21-inch tube was moved to the stern and two additional 18-inch tubes were added in the bow. They carried two 21-inch and eight 18-inch torpedoes. The G-class submarines were also armed with a single

deck gun A deck gun is a type of naval artillery mounted on the deck of a submarine. Most submarine deck guns were open, with or without a shield; however, a few larger submarines placed these guns in a turret. The main deck gun was a dual-purpose ...

Career

After commissioning, ''G4'' was sent to join 11th Submarine Flotilla at Blyth. On 19 June 1916, ''G4'' was patrolling in the

Kattegat The Kattegat (; sv, Kattegatt ) is a sea area bounded by the Jutlandic peninsula in the west, the Danish Straits islands of Denmark and the Baltic Sea to the south and the provinces of Bohuslän, Västergötland, Halland and Skåne in Sweden ...

when she encountered the German merchant ship SS ''Ems'', carrying a load of oil, zinc and copper plates from

Oslo Oslo ( , , or ; sma, Oslove) is the capital and most populous city of Norway. It constitutes both a county and a municipality. The municipality of Oslo had a population of in 2022, while the city's greater urban area had a population of ...

Lübeck Lübeck (; Low German also ), officially the Hanseatic City of Lübeck (german: Hansestadt Lübeck), is a city in Northern Germany. With around 217,000 inhabitants, Lübeck is the second-largest city on the German Baltic coast and in the stat ...

, and stopped her with a warning shot. Once the German ship's crew had abandoned ship, ''G4'' fired two torpedo at ''Ems'', both of which missed, and then sank the merchant ship with gunfire. A second German merchantman escaped to neutral Swedish waters. Sweden protested about the sinking of ''Ems'', claiming that it took place within Swedish

territorial waters The term territorial waters is sometimes used informally to refer to any area of water over which a sovereign state has jurisdiction, including internal waters, the territorial sea, the contiguous zone, the exclusive economic zone, and potenti ...

, but Britain denied this. The dispute between Sweden and Britain about the sinking of ''Ems'' was still ongoing at the end of the war. At some point between 20 August 1916 and 3 October 1916, she went to Scapa Flow and left there to go to

Murmansk Murmansk (Russian: ''Мурманск'' lit. "Norwegian coast"; Finnish: ''Murmansk'', sometimes ''Muurmanski'', previously ''Muurmanni''; Norwegian: ''Norskekysten;'' Northern Sámi: ''Murmánska;'' Kildin Sámi: ''Мурман ланнҍ'') i ...

(then called Romanov), arriving on 20 October 1916. She left there on 15 November, arriving in Kirkwall five days later. ''G4'' then spent the rest of the First World War conducting patrols in the North Sea from Blyth, and was there at the time of the armistice.

Notes

References

* * * * {{DEFAULTSORT:G04 British G-class submarines World War I submarines of the United Kingdom Ships built in Chatham Royal Navy ship names 1915 ships