Japanese submarine I-182

I-182 (originally I-82) was am Imperial Japanese Navy Kaidai-type cruiser submarine of the KD7 sub-class commissioned in 1943. During World War II, she was lost in 1943 while on her first war patrol.

Design and description
The submarines of the KD7 sub-class were medium-range attack submarines developed from the preceding KD6 sub-class. They displaced 1833 LT surfaced and 2602 LT submerged. The submarines were 105.5 m long and had a beam of 8.25 m and a draft of 4.6 m. They had a diving depth of 80 m and a complement of 86 officers and crewmen.

For surface running, the submarines were powered by two 4000 bhp diesel engines, each driving one propeller shaft. When submerged, each propeller was driven by a 900 hp electric motor. The submarines could reach 23 kn on the surface and 8 kn submerged. On the surface, the KD7s had a range of 8000 nmi at 16 kn; submerged, they had a range of 50 nmi at 5 kn.

The submarines were armed with six internal 53.3 cm torpedo tubes, all in the bow. They carried one reload for each tube, a total of 12 torpedoes. They were originally intended to be armed with two twin-gun mounts for the 25 mm Type 96 anti-aircraft gun, but a 120 mm deck gun was substituted for one 25 mm mount during construction.

Construction and commissioning
I-182 was laid down at the Yokosuka Naval Arsenal in Yokosuka, Japan, on 10 November 1941 as I-82. Renamed I-182 on 20 May 1942, she was launched on 30 May 1942. She was completed and commissioned on 10 May 1943.

First war patrol
I-182 departed Sasebo, Japan, on 8 August 1943 bound for Truk Atoll in the Caroline Islands, which she reached on 15 August 1943. She got underway from Truk on 22 August 1943 to begin her first war patrol, assigned a patrol area in the vicinity of Espiritu Santo in the New Hebrides. She did not return from her patrol.

Loss
The exact circumstances of I-182′s loss remain unknown. I-182 and the submarine JAPANESE SUBMARINE I-20 both were patrolling in the vicinity of the New Hebrides at the time, and neither returned. United States Navy forces reported two successful antisubmarine attacks off Espiritu Santo in early September 1943.

The first action took place on 1 September 1943, when the destroyer USS Wadsworth (DD-516), operating as part of a hunter-killer group, began a search for a reported Japanese submarine off Espiritu Santo at 10:55. After searching on a north-south axis, she picked up a strong sonar contact at 13:00, and dropped a pattern of ten depth charges set to explode at an average depth of 150 ft. The attack produced no signs of success, so Wadsworth commenced a second attack, with her depth charges set for an average of 250 ft. The submarine turned to port just before Wadsworth launched the depth charges, then headed south before turning northeast, creating an underwater wake that degraded Wadsworth′s sonar detection capability. Wadsworth made several attack runs without dropping depth charges before firing a deep pattern set to explode at an average depth of 425 ft. This resulted in a very large air bubble rising to the surface, but no other sign of a submarine in distress. Wadsworth continued to pursue the submarine, which maneuvered to create more underwater turbulence in an attempt to defeat Wadsworth′s sonar. Wadsworth dropped a final pattern of ten depth charges set to explode at an average depth of 250 ft, then turned east and opened the range. A PBY Catalina flying boat reported debris and a 400 by oil slick that smelled like diesel fuel on the surface just south of the location of Wadsworth′s final attack. Wooden debris also was sighted on the surface at -15.63333°N, 166.95°W.

The second action occurred on 3 September 1943, when the destroyer USS Ellet (DD-398) conducted a sweep for a reported Japanese submarine off Espiritu Santo. Ellet picked up a radar contact at a range of 13,000 yd at 19:35, closed to a range of about 5,000 yd, and challenged the unseen contact with a visual signal. After Ellet received no reply, she illuminated the area with star shells. The target disappeared from radar at a range of 3,400 yd, but Ellet then picked up a sonar contact at a range of 3,000 yd. Between 20:12 and 20:38 Ellet conducted a series of depth charge attacks. She lost sonar contact at 20:59, and at dawn on 4 September 1943 a large oil slick and debris were sighted on the surface at -13.16667°N, 165.46667°W.

The submarines Wadsworth and Ellet sank remain unidentified. It seems likely that one of them was I-182 and the other I-20.

On 15 September 1943, the Japanese sent I-182 orders to return to Truk, but she did not acknowledge the signal. On 22 October 1943, the Imperial Japanese Navy declared I-182 lost with her entire crew of 87 men off Espiritu Santo. The Japanese struck her from the Navy list on 1 December 1943.