Kaidai VI class, SUBMARINES, 潜水艦
 
IJN Submarine I-168
Displacement: 1,785 t Surf., 2,440 t Sub. Machinery: 2 diesels, 2 electric motors, 2 shafts   Bow Torpedo Tubes: 4×21 in (533 mm)
Max Length: 343 ft 6 in 104.7 m Power Surf./Sub.: 9,000 / 1,800 hp 6711 / 1342 kW Aft Torpedo Tubes: 2×21 in (533 mm)
Beam: 26 ft 11 in 8.2 m Speed Surf./Sub.: 23 / 8.25 kts 42.6 / 15.3 km/h Torpedoes: 14×Type 95
Draft: 15 ft 0 in 4.6 m Range Surf./Sub.: 14,000 / 65 nm 26 000 / 120 km DP Gun: 1×3.9 in (100 mm)/50
Complement: 70 officers and enlisted Operating Depth: 245 ft 74 m AA MG: 1×.52 in (13.2 mm)

  * Specifications for Kaidai VIa subtype, early production (I-168I-170).

The initial design of IJN “Navy Large Type Submarine” (was shortened to Kaidai) was based on the German U-139 class long- range submarine commerce raiders from the WWI. Thirty-five ships of the type were divided into seven classes, Kaidai I-VII.

Eight submarines of Kaidai VI class were completed between 1934 and 1938. The ships were longer and fitted with more powerful diesels then their predecessors, so these boats had the highest surface speed of any submarines in the world in the mid-1930s. The submarines were armed with six 21 in (533 mm) torpedo tubes and fourteen lethal Type 95 kerosene-oxygen torpedoes. The first three boats carried the 3.9 in (100 mm) gun, the last five mounted a 4.7 in (120 mm) deck gun. All boats were also equipped with one or two .52 in (13.2 mm) anti-aircraft machine guns.

The class was active during the Midway operation, when I-168 scored the biggest Japanese submarine success of the war when she torpedoed and sank the already damaged fleet carrier USS Yorktown (CV-5), and destroyer USS Hammann (DD-412) off Midway on June 6.

 

Ship Builder Laid Down    Launched    Commisioned       Fate
 伊一六八  I-168 Kure Naval Arsenal 18 Jun 1931     26 Jun 1933     31 Jul 1934     Sunk in action 27 Jul 1943
 伊一六九  I-169 Mitsubishi, Kōbe Shipyard 22 Dec 1932   15 Feb 1934   28 Sep 1935   Sunk in action   4 Apr 1944
 伊一七十  I-170 Sasebo Naval Arsenal 25 Jan 1933   14 Jun 1934    9 Nov 1935   Sunk in action 10 Dec 1941
 伊一七一  I-171 Kawasaki, Kōbe Shipyard 15 Feb 1933   25 Aug 1934   24 Dec 1935   Sunk in action 30 Jan 1944
 伊一七二  I-172 Mitsubishi, Kōbe Shipyard 16 Dec 1933    6 Apr 1935    7 Jan 1937   Sunk in action 10 Nov 1942
 伊一七三  I-173 Kawasaki, Kōbe Shipyard   5 Sep 1933   20 Jun 1935    7 Jan 1937   Sunk in action 27 Jan 1942
 伊一七四  I-174 Sasebo Naval Arsenal 16 Oct 1934   28 Mar 1937   15 Aug 1938   Sunk in action 12 Apr 1944
 伊一七五  I-175 Mitsubishi, Kōbe Shipyard  1 Nov 1934   16 Sep 1936   18 Dec 1938   Sunk in action 17 Feb 1944