Japanese submarine I-165 in 1932.jpg
I-65, similar to I-70, pictured here in 1932.
Empire of Japan
Name: I-70
Builder: Sasebo Naval Arsenal
Laid down: 25 January 1933
Launched: 14 June 1934
Commissioned: 9 November 1935
Homeport: Kure
Fate: Sunk on December 10, 1941 by SBD Dauntless aircraft from USS Enterprise off the coast of the Hawaiian Islands.
General characteristics
Class and type: KD6 Type, Kadai type submarine
  • 1,400 (1,785 maximum) tons surfaced
  • 2,440 tons submerged[1]
Length: 322 ft 10 in (98.4 m)
Beam: 26 ft 11 in (8.2 m)
Draught: 15 ft 0 in (4.6 m)
Propulsion: Twin shaft Kampon 9,000 bhp (6,711 kW)/two stroke diesels
  • 23 knots (43 km/h; 26 mph) diesel
  • 8.2 knots (15.2 km/h; 9.4 mph) electric[1]
Range: 14,000 nmi (26,000 km; 16,000 mi)[1]
Test depth: 230 ft (70 m)
Complement: 60–84 officers and enlisted

The Japanese submarine I-70 was a Kaidai type of cruiser submarine active in World War II. A KD6 boat, I-70 was built for the Imperial Japanese Navy (IJN) in the early 1930s. At that time it was commanded by Commander Sano Takao.[2]

Early career

I-70 was laid down on January 25, 1933 in Sasebo Naval Arsenal and was launched almost a year later on June 14, 1934. It was commissioned on November 9, 1935. On May 12. 1941, I-69 (another Japanese submarine) collided with I-70 creating a gash in the latter's starboard tanks and conning tower. Both were able to make it to Yokosuka for repairs.

Pearl Harbor attack and loss

I-70 was part of a group of submarines sent to patrol of the coast of the Hawaiian Islands during the attack on Pearl Harbor on December 7, 1941 (December 8 in local Japan time). That day, it failed to answer a radio call. The last radio received from the submarine was on December 9, 1941 when it reported seeing USS Enterprise near Naval Station Pearl Harbor.

On December 10, 1941, it was sighted by a Douglas SBD-2 Dauntless aircraft from USS Enterprise from VS-6 after 6:00 AM. The aircraft scored a near-miss with a 1,000-pound (454 kg) bomb which damaged its hull and prevented it from diving. Later that day, another SBD of VS-6 saw the damaged submarine. Although the submarine attempted to maneuver and was even able to fire its 13 mm deck machine gun, the SBD was able to climb to 5,000 feet (1,500 m) and hit the ship amidships with a bomb, blowing several gunners overboard. The sub stopped and then disappeared underwater about 45 seconds later at coordinates 23°45′N 155°35′W﻿ / ﻿23.750°N 155.583°W﻿ / 23.750; -155.583﻿ (Japanese submarine I-70)Coordinates: 23°45′N 155°35′W﻿ / ﻿23.750°N 155.583°W﻿ / 23.750; -155.583﻿ (Japanese submarine I-70).[2]


  1. ^ a b c Jentschura p. 172
  2. ^ a b "Imperial Submarines". www.combinedfleet.com. Retrieved 2018-12-16.