The Grampus class submarines were a group of minelaying submarines built for the British Royal Navy in the late 1930s. These boats are sometimes referred to as the Porpoise class. A single prototype, HMS Porpoise was built in 1932 and five modified follow-on ships were built between 1936 and 1938. The mines were stored in a special "gallery" with a conveyor belt built into the outer casing as pioneered by the converted submarine HMS M3. These boats were of a saddle tank type. They were used extensively in the Mediterranean, particularly to supply the besieged island of Malta in a service nicknamed the "magic carpet". A minelayer is a naval ship used for deploying sea mines. ... German UC-1 class World War I submarine A model of Günther Priens Unterseeboot 47 (U-47), German WWII Type VII diesel-electric hunter-killer (SSK) submarine Inside of the Argonaute, showing the typical obstructed, tiny space of a post-WWII diesel attack submarine. ... The Royal Navy of the United Kingdom is the oldest of the British armed services (and is therefore the Senior Service). ... The M class submarines were a small class of Diesel electric submarine used by the British Royal Navy during World War I. The main distinguishing feature of the M class was a 12_inch gun mounted in a turret forward of the conning tower. ... The Mediterranean Sea is an intercontinental sea positioned between Europe to the north, Africa to the south and Asia to the east, covering an approximate area of 2. ...

General characteristics

From Conway's All the World's Fighting Ships 1922-1946:

• Displacement
  • Surface - 1,768 tons (Porpoise), 1,810 tons (others)
  • Submerged - 2,035 tons (Porpoise), 2,157 tons (others)
• Length - 88 m (298 ft) (Porpoise), 89.30 m (293 ft) (others)
• Beam - 9.09 m (29 ft 10 in) (Porpoise), 7.77 m (25 ft 6 in) (others)
• Draught - 4.84 m (15 ft 10 in) (Porpoise), 5.13 m (16 ft 10 in) (others)
• Machinery - 2 shaft, Diesel (3300 hp) plus electric (1630 hp),
• Speed
  • 15.5 knots surfaced
  • 8.75 knots submerged
• Armament
  • 6 - 21 inch torpedo tubes (bow 12 torpedoes carried)
  • 1 - 4 in deck gun
  • 50 mines
• Crew: 59

Ships

Vickers Armstrong (Aircraft) company logo Vickers, founded as the Vickers Company in 1828, was a British manufacturer, primarily of military equipment, traditionally based in Barrow-in-Furness. ... HMS Grampus (N56) was a submarine of the Royal Navy, the lead ship of her class. ... Chatham Dockyard, located on the River Medway in Kent, England, came into existence at the time when, following the Reformation, relations with the Catholic countries of Europe had worsened, and thus requiring added defences. ... Vickers Armstrong (Aircraft) company logo Vickers, founded as the Vickers Company in 1828, was a British manufacturer, primarily of military equipment, traditionally based in Barrow-in-Furness. ... Vickers Armstrong (Aircraft) company logo Vickers, founded as the Vickers Company in 1828, was a British manufacturer, primarily of military equipment, traditionally based in Barrow-in-Furness. ... HMS Seal (M37/N37) was a Grampus-class mine-laying submarine of the Royal Navy. ... Chatham Dockyard, located on the River Medway in Kent, England, came into existence at the time when, following the Reformation, relations with the Catholic countries of Europe had worsened, and thus requiring added defences. ...

References

• Conway's All the World's Fighting Ships 1922-1946
• - page from U-boat.net
• - page from submariners.co.uk