Japan Coast Guard patrol vessel PLH32 Akitsushima. Photo by Kaidai

NavyRecognition is reporting that the Japanese Coast Guard is once again building very large coast guard cutters with the launch of Reimei (PLH 33).

Mitsubishi Heavy Industries (MHI) recently launched a brand new patrol vessel for the Japan Coast Guard (JCG). This vessel is a variant of the Shikishima-class, with two previous vessels built in 1992 and 2013. Two more vessels are also scheduled to be built in the future (emphasis applied–Chuck).

This class is going to be something of an oddity, because it looks like there will be at least 30 years between the commissioning of the first ship and the fifth. In fact the Japanese may be planning to replace the first ship of the class with the fifth (that is only speculation on my part, but the Japanese do not keep there ships nearly as long as the USCG. Referencing my Combat Fleets of the World from 2013, the Japan Coast Guard had no ships older than 35 years).

Before the Chinese built their very large Coast Guard cutters, the two earlier ships of this class, Shikishima (commissioned 1992) and her sister ship, Akitsushima (commissioned 2013), were largest cutters in the world, at 150.0m (492 ft), 9300 ton (full load), twice as large as Bertholf class cutters.

The South Koreans have also built some exceptionally large cutters. None of these ships have particularly large crews. Crews are about the same size or smaller than the crews of the Bertholf class. All seem to be good for about 25 knots and have facilities for two helicopters.

Armament:

The first two Japanese ships don’t have the 76mm guns found on the extremely large Chinese and South Korean cutters, but they are well armed for cutters with four gun mounts on each ship. There does seem to be some variation in the way the Japanese ships are armed–not too surprising considering the first two ships were commissioned 21 years apart, and seven years will separate this third ship from the second of the class.

Japanese 20 mm/76 Gatling Gun. Note the camera for remote targeting. JMSDF Photograph.

Just about all Japan Coast Guard cutters have the 20mm Sea Vulcan, which uses the same 20mm guns as those in the Phalanx Close in Weapon System (CIWS) but in a simpler mount. They have a 3000 round per minute rate of fire and a reported effective range of 1,625 yards (1,490 m). The first ships of the class had two mounts forward of the bridge at the O-2 deck level.

The first two ships have two mounts for the Oerlikon 35mm. These guns have a 550 round per minute rate of fire per gun and a reported effective range against surface targets of 8,700 yards (8,000 m). The first ship has two twin mounts, but it appears the second has two simplified single mounts. If the third ship follows typical Japan Coast Guard practice, the larger mounts will continue to be in the 30 to 40mm range. If on the other hand, they mount something larger, it will mark a departure for the JCG, I would assume, in response to the increased militancy of the China Coast Guard.

In the world of Asian Coast Guards, it may simply be that their large size is their primary armament. These nations seem to regularly engage in shoving matches. In at least one case, the China Coast Guard reportedly sank a Vietnamese fishing vessel by ramming.