Mizuho (PLH-41) is a future large patrol boat of the Japan Coast Guard and a new class. It was launched in November 2018 by Mitsubishi Heavy Industries (MHI)’s Shimonoseki Shipyard & Machinery Works in South West Japan.
Pictures by local ship spotter @PLH22_Yashima (おはぎ) show the vessel fitted with a BAE Systems Bofors 40Mk4 40mm main gun. This contract was never announced before. Hence Japan becomes the second export customer of this gun system after Brazil, the launch customer. The Swedish Navy recently ordered this gun as well (which is manufactured locally in Sweden).
Mizuho is a large patrol vessel displacing 6,000 tons and measuring 134 meters in length. In addition to the 40mm main gun, it will be fitted with two JM61R-MS 20mm Gatling gun systems. It is also equipped with six water cannons and can accommodate two Sikorsky S-76D helicopters of the JCG. The vessel is expected to be commissioned later this year. It will be reportedly join the flotilla tasked with patrolling the Senkaku Islands, which will limit the need to detach large patrol boats from other bases. The first of class vessel will have a sister-ship: PLH42 “Shunri”.
Accoding to BAE Systems Bofors, the 40mm gun is used as a general purpose system to combat both air and surface threats, but it can also be used against coastal ground targets.
The Bofors 40Mk4 has the capability to rapidly switch between optimised ammunition types, including programmable 40mm 3P all-target ammo. It can go from warning to destruction in less than 0.5 seconds. The 3P ammo can be programmed for optimised effect against any target, including airburst patterns for new threats that were previously impossible to engage. The automatically loaded, remotely controlled weapon can also be locally controlled as a backup, equipping the operator for any scenario.