Bjørgvin-class coastal defence ship

Bjørgvin as HMS Glatton
Class overview
Operators:	Royal Navy
Preceded by:	Eidsvold-class battleship
Succeeded by:	None
Built:	1912–1914
In commission:	1914–1928
Completed:	2
Lost:	1
General characteristics
Type:	Coastal defence ship
Displacement:	4,900 long tons (4,979 t)
Length:	94 m (308 ft 5 in)
Beam:	16.8 m (55 ft 1 in)
Draught:	5.4 m (17 ft 9 in)
Propulsion:	Coal-fired reciprocating steam engines, 4,000 shp (2,983 kW)
Speed:	15 knots (17 mph; 28 km/h)
Complement:	305
Armament:	2 × 24 cm (9.4 in) guns 4 × 15 cm (5.9 in) guns 6 × 10 cm (3.9 in) guns 2 × submerged torpedo tubes
Armour:	Belt: 7 in (180 mm) Bulkheads: 4 in (100 mm) Barbettes: 8 in (200 mm) Turrets: 8 in (200 mm) Decks: 2.5 in (64 mm) Conning tower: 8 in (200 mm)

The Bjørgvin class coastal battleships were ordered by Norway in 1912 to supplement the older Eidsvold and Tordenskjold-class coastal defence ships. The two ships laid down were compulsorily purchased by the Royal Navy when World War I broke out, and classified as monitors. The British government paid Norway £370,000 as compensation for each ship.

Ships in class

• Bjørgvin (1912) - Compulsorily purchased by the British Navy and renamed HMS Glatton, blew up in September 1918.
• Nidaros (1912) - Compulsorily purchased by the British Navy and renamed HMS Gorgon.

Description

The Bjørgvin class would be significantly more heavily armed than the previous Eidsvold class:

• Two 24 cm/50 guns, which in British service were relined to use standard British ammunition and became 9.2"/51.^[1] These were considered among the longest-ranged guns in the world in 1918. As designed, they would have fired a 190 kg (419 lb) projectile with a muzzle velocity of 884 m/s (2,900 ft/s), capable of penetrating 22.2 cm (8.75 in) of face-hardened armour at a range of 7,000 m (7,650 yards).
• Four 15 cm/50 in single turrets - one aft, one fore, two midships (one on either side). In British service they were relined to take standard 6 inch (15 cm) ammunition.^[2]
• Six 10 cm (3.94 in) guns.
• Two submerged torpedo tubes.

In addition to the heavier armament, the two ships of the Bjørgvin class were also significantly better armoured, with her armour better distributed:

• 7 inch (17.78 cm) thick armour in the belt
• 8 inch (20.32 cm) thick armour on the turrets
• 8 inch (20.32 cm) thick armour in the barbettes
• 2.5 inch (6.35 cm) thick armoured deck
• 8 inch (20.32 cm) thick armour on the conning tower
• 4 inch (10,16 cm) thick armoured bulkheads

External links

• Model of KNM Bjørgnvin, head on view
• Details of the forecastle and details of bridge.
• The loss of the HMS Glatton, an "interesting little ship", retrieved 15 January 2007

Notes

References

• Model of KNM Bjørgnvin, from the website of the Norwegian Armed Forces Museum, retrieved 9 December 2005
• On guns, see Notes.
• Naval History via Flix: KNM Nidaros, retrieved 11 December 2005
• Naval History via Flix: Technical Details of Ship HMS Gorgon, retrieved 9 December 2005