Staff Writer (Updated: 7/27/2015):
Haruna was ordered in 1911 and Kawasaki Shipyards was commissioned for her construction. Her keel was laid down on March 16th, 1912 and she was launched on December 14th, 1913. The vessel's official commissioning came on April 19th, 1915. Haruna held a displacement value of 36,600 tons (long) and measured 728.3 feet long with a beam of 101.7 feet and a draught of 31.9 feet. Her propulsion machinery constituted 36 Yarrow boilers helping to develop 64,000 horsepower to four shafts underneath the stern. Maximum speed in ideal conditions reached 26 knots. Her profile was consistent with the period, the superstructures amassed around midships and bookended by two main masts with several smoke funnels being featured. A very pointed bow ensured speeds could be maintained in relatively calm seas and onboard space allowed for a crew of 1,360 to be carried. Armor protection included 230mm at the turrets, 200mm at the belt and up to 70mm along the deck.
Armament was a key consideration for the class and the main gun arrangement was made up of 8 x 14" guns in four twin-gunned turrets, two fitted forward and two fitted aft. This marked the first class in the world to feature this large caliber armament as a uniformed main battery. 16 x 6" guns were also fitted and these across sixteen single-gunned turrets set about midships. 8 x 76mm guns were installed as a final line of firepower. The original armament suite was rounded out by the inclusion of 8 x 530mm (21") submerged torpedo tubes - a common trait of pre-World War 1 warships.
Following successful conclusion of her trials period, Haruna was made a part of the Third Battleship Division (Second Fleet) and began service in the East China Sea for her part in World War 1 (1914-1918). Following the war, during September of 1920, an accident at one of the No.1 turret guns killed seven and caused damage to the installation. A faulty fuse on one of the charge bags was blamed for the explosion. She entered reserve status as the world wide military followed all nations with the conclusion of World War 1. The Kongo-class of the IJN was one of the few notable ship groups to survive the naval purge that was seen after the signing of the Washington Naval Treaty. This treaty served to limit naval arms production and help stave off another global conflict precipitated by a major arms race.
Because of the limitations imparted on the IJN by the Treaty, no new capital ships were ordered and built for a time and this forced the service to modernize and modify existing vessels through greater firepower, armor and capabilities. Haruna was selected for such work in mid-1926 and construction took the better part of two years in which her armor was upgraded (notably exceeding the limitations of the Washington Naval Treaty) and internal spaces improved. Torpedo bulges were added along her sides to improve her survivability amidst the growing threat of submarine use around the globe. Her design also accepted three reconnaissance floatplanes. The boiler arrangement was changed to a more modern and efficient design which resulted in the loss of her forward funnel and a resizing of her existing funnel structure. The new machinery increased ocean-going speeds to 30 knots. Because of the changes instituted, Haruna was now reclassified as a battleship. She joined the Forth Battleship Division in 1928 and entered reserve status in 1930.