These are all aluminum patrol boats built by Sumidagawa Shipyard. This ship built in 1993 has a speed of 35.40 KT at a horsepower of 4/4 MCR. In 1995, we developed a new boat called TAKEYORI. We succeeded in realizing a speed of 42.92 KT at 4/4, maximum 45 KT.

　

　

　

 ※ is NAMIHAYA and is TAKEYORI. This shows that even with the same horsepower, there is a difference in speed of 6 KT. The speed length ratio of this ship is Vs (42.92)√Lwl (22.5)42.92/ 4.743=9.04, classifying it in the category of ultra-high speed ships. You can see that despite having even horsepower, the speed differs considerably according to the type of ship.

 The N11-18 & 19 and N11-36 & 37 built in 1999, use three main engines GM16V-92T, 3 x 1130 ps , and have a total horsepower of 3,390. The N12-19, 20, 41, and 42 use three main engines MAN D2842LE406, or 3 x 1090, with total horsepower of 3270 ps, which is 120 ps lower than the former.

　

 We reexamined the weight of the equipment of the boat, main engine, and equipment for engines and electricity, and finally succeeded in reducing the total weight by 5 tons.

 We did this by reducing the weight of the main engine by 3.5 tons, changing the material of the rudder and shaft bracket to titanium alloy, changing the exhaust gas and seawater pipes to titanium, changing all ship bolts and nuts to titanium, incorporating a honeycomb structure for part of the boat outfitting, and using lightweight cables.