Go-1, 2, 5, 8 Class Submarine
Kokoan interest in Submarine began to dawn after the Russo-Japanese war, resulting in the creation of a small fleet of foreign-built units at the turn of the first world war.
The first was a single boat intended for training duties. It was ordered in the United Kingdom and built by Vickers. This was nothing more than a de-powered C-class submarine delivered in 1909. 43,3m long, 4,1m wide and with a surfaced draft of 3,4m. It displaced 286 T surfaced and 321 submerged. It could do 12knots surfaced but only 4 submerged. Range was 1.500 nautical miles ( 2.778km) surfaced and 55 (102km) submerged. Two forward mounted 450mm torpedoes made up the armamament.
Recieving the bare and simple denomination go-1 (literally nothing more than N°1) the surbmarine served into her intended training role until 1924, when it was replaced by the newer Ki-1 units. It was scrapped that very same year.
Following the delivery of Go-1, Koko no Kaigun ordered three more C-class units from Vickers. This time they had not de-rated engines and performed like their British counterparts. 43,7m long, 4,1m wide and with a surfaced draft of 3,4m they displaced 294T surfaced and 329 submerged. Surfaced speed was still 12 knots, but submerged increased to 8. Range too increased to 2.000 nautical miles (3.704km) surfaced, while submerged remained at 55. The armament was still two 450mm torpedo tubes forward.
named Go-2 through 4, the three submarines were delivered in 1911-12. They took part in some short-range patrols during WWI and served until the late 1920's when the newer and larger Ki-3 ones arrived. All three were decommissioned in 1929.
Koko turned again on the British for more submarines in 1913, ordering another class of three, named Go-5, 6 and 7. Based on the E-class, they were 55m long, had a beam of 4,6 and a surfaced draft of 3,8m. Displacement was 662 T surfaced and 807 t submerged. They had a 3.000 nautical miles (5.556km) range surfaced and 65 (120km) submerged. They were armed with a single 76mm deck gun, two bow and one stern 450mm torpedo tubes, but had no beam ones like other British boats. When world War One broke out the submarines -with n°7 yet to be laid down- were requisitioned by the British Government with the intention of commissioning them into the Royal Navy. To be used against German forces. Ultimately, they were delivered to Koko no Kaigun between late 1916 and early 1917 as a sort of reparation for the loss of the battlecruiser Kuromegami against the Thiarian during the Battle of Tristan da Cunha in June 1916. They were however delivered without the 76mm deck gun.
The three submarines reached the pacific theater too late to be useful in any way, as the German forces had been long dealt with. After the end of WWI all three finally recieved ther deck gun and went on to serve for a decade until the Ki-3 class started being commissioned.
They were ultimately decommissioned between 1929 and 1930.
The Go-8 would become the last class of Kokoan submarines to be ordered and built abroad. Plans for a follow-up to earlier submarines had been considered since early 1914, with a possible order to be finalized in 1916. Eventually, the breakout of WWI meant that the Kokoan request only became reality in 1918. As previous practice the ships were built in British shipyards and based on british designs, this time the second batch of the L-class. The initial contract called for ten boats to be built and delivered by 1926 in order to replace the older and smaller submarines while Koko worked on getting domestic-built units as well.
The subsequent falling out in diplomatic relationships between Koko, Japan and the British Empire, with the subsequent dissolution of the anglo-Japanese alliance resulted in only three submarines being built and delivered by 1922.
The three units were 67,5m long, had a beam of 7,1 and a surfaced draft of 4m. They displaced 870T surfaced and 1.074 submerged. Their maximum surface speed was 17knots while the sumberged one was 9,5. Maximum range surfaced was 2.800 nautical miles (5.185km), while submerged was 80 nm (148km). Armament was sub-par, with only four 450mm tubes at the bow (thus lacking the two beam tubes), and all three submarines were delivered without their deck gun once again.
Nevertheless, they still were the most advanced submarines Koko had in service at the time, and they soon recieved a 76mm gun to be fitted forward of the sail.
They served until 1931, when they were all retired. Both because of newer units entering service and the tonnage limitations of the london Naval Treaty.
Ships in class: (laid down-launched-commissioned - fate)
Go-1 1907-1908-1909 - Decommissioned 1924
Go-2 1910-1911-1911 - Decommissioned 1929
Go-3 1910-1911-1911 - Decommissioned 1929
Go-4 1910-1912-1912 - Decommissioned 1929
Go-5 1913-1914-1916 - Decommissioned 1929
Go-6 1913-1915-1917 - Decommissioned 1930
Go-7 1915-1916-1917 - Decommissioned 1930
Go-8 1918-1919-1920 - Decommissioned 1931
Go-9 1919-1921-1922 - Decommissioned 1931
Go-10 1920-1921-1922 - Decommissioned 1931
Go-11 / - / - / - Canceled
Go-12 / - / - / - Canceled
Go-13 / - / - / - Canceled
Go-14 / - / - / - Canceled
Go-15 / - / - / - Canceled
Go-16 / - / - / - Canceled
Go-17 / - / - / - Canceled