Gyoraitei 4 Class Torpedo Boat:
Planned to supplement the lacking G-1 class, the Gyoraitei-4 units were built in Germany for Koko no Kaigun like their predecessors. The design was vastly enlarged, resulting in avessel 64,7m long, 6,2m abeam and with a hull draft of 1,4m (2,6m to the propeller and rudder guard). Displacement, at 288 tons, was nearly three and a half times larger than thet of the previous class. the larger hull and displacement allowed for fititng more powerful engines, resulting in a top speed of 26,5knots. armament was composed by a single 88mm cannon and to 37mm ones. Two 450mm trainable torpedo tubes fitted on centerline completed the set.
The first ship, Gyoraitei 4, or G-4, was deliviered to Koko no Kaigun in 1889. Despite lacking her torpedo equipment -which was fitted only two years later- the naval staff was much more satisfied with the new vessel, quickly extending the order to ten vessels. Gyoraitei 5 was the first to be delivered fully fitted, in 1891. Like the previous Gyoraitei 1 class, the new ships were also painted in the standard black paint that was common on German Torpedoboots at the time.
The folowing units were deliviered with a pace of one ship each year up to 1898. The last one, G-13, was delayed until 1900 for bureaucratic reasons following the Kokoan switch from German to British built ships as a consequence of the toumachi treaty of 1897. Gyoraitei 13 was repainted into Kure grey upon delivery, with the other units already in service following shortly thereafter.
The first three units were decommissioned between 1903 and 1905 while the larger Kuchikukan 1 units were entering service. The other seven sisters were refitted during the same timeframe, losing the 76mm and 37mm cannons in lieu of one 76mm 12-punder gun and two 6,5mm rapid fire guns. The torpedo tubes were also switched to newer units, compatible with the Japanese built 450mm torpedoes. Finally a compass platform was fitted between the funnels.
Initially planned to be retired around the mid 1910s, G-7 through G-13 had their service life extended when WWI started. With the more recent, and advanced, units leaving port to join the naval blockade off Tsingtao or for patrols around the Pacific, the older ships served for coastal patrol duties until the end of the conflict. Starting in 1919 the last seven units began to leave the fleet, the last gone by 1922. The last four however had their service life further extended when the Naval Staff decided to convert them into Minesweepers.
Ships in class: (laid down-launched-commissioned - fate)
Gyoraitei 4 1888-1889-1889 - Decommissioned 1903
Gyoraitei 5 1890-1891-1891 - Decommissioned 1904
Gyoraitei 6 1891-1892-1892 - Decommissioned 1905
Gyoraitei 7 1892-1893-1893 - Decommissioned 1919
Gyoraitei 8 1893-1894-1894 - Decommissioned 1920
Gyoraitei 9 1894-1895-1895 - Decommissioned 1921
Gyoraitei 10 1895-1896-1896 - Decommissioned 1922 (converted to Minesweeper)
Gyoraitei 11 1896-1897-1897 - Decommissioned 1922 (converted to Minesweeper)
Gyoraitei 12 1896-1897-1898 - Decommissioned 1922 (converted to Minesweeper)
Gyoraitei 13 1897-1898-1900 - Decommissioned 1922 (converted to Minesweeper)