1914 and the Great War explodes across Europe, naval battles were fought with cruiser sized vessels in the South Atlantic Ocean, North Sea, and Mediterranean Sea. The big German merchant raiders had proved elusive and when cornered, hard to kill. The Algarvian Admiralty decided to produce a hybrid that could beat any German cruiser and still have a chance to either run or fight if they ran across something bigger.
Laid down in early 1915, the four Vengeance class were originally classed as battlecruisers, but were reduced to Armoured Cruisers in 1918, and eventually Heavy cruisers after 1930. These were big ships and were larger than both the Invincible and Indomitable class ships. 1917, and the knowledge of the trials in Britain of ships to handle wheeled aircraft for both take off and landing, lead to the repurposing of the later two of the class, Venomous and Vendetta which had been laid down in 1916.
The original armament of 10, 6, and 3 guns, proved the problem that had caused the early demise of the semi-dreadnought as a type. The 10 and 6 shell splashes were hard to distinguish from each other at long ranges. This lead to the 6 guns being replaced with single 4.5 on a one for one basis. No other major changes were made to the armament until 1937 when the 3 AA and the light AA machine guns were removed and the new Bofors twin 40mm weapons were fitted. From 1937 refits and new equipment were added regularly as more and more electronic aids and systems became available. 1937-38 the gun armed members of the class received bulges to help with both stability and underwater protection.
1922 and the Washington Treaty said that the Vengeance class cruisers could not be retained under cruiser tonnage but would have to be classed as capital ships. Two of the 12 Newport class battleships were deleted in favour of keeping the Vengeance class ships.
Gun armed ships 1918
Displacement: 18,000 tons normal, 22,500 tons full load.
Dimensions: 634 x 76 x 26 feet
Machinery: 2 shafts, turbines, 80,000shp
Speed: 30 knots
Endurance: 8000 miles at 14 knots
Armour: 5 belt, 2 deck, 6, 3, 2 turrets
Armament:
8 x 10 (4x2)
8 x 6 (8x1) replaced with 4.7 1920
5 x 3 AA (5x1)
Crew: 750
Gun armed cruisers 1940
Displacement: 19,300 tons standard, 24,000 tons full load.
Dimensions: 634 x 84 x 26 feet
Machinery: 2 shafts, turbines, 80,000shp
Speed: 29 knots
Endurance: 8,000 miles at 14 knots
Armour: 5 belt, 2 deck, 6/3/2 turrets
Armament:
8 x 10 (4x2)
12 x 4.5 (6x2)
20 x 40mm (10x2)
Aircraft: 1
Crew: 825