Japanese submarine Ro-48
Ro-48 was an Imperial Japanese Navy Kaichū type submarine of the K6 sub-class. Completed and commissioned in March 1944, she served in World War II and was sunk in July 1944 during her first war patrol.
| History | |
|---|---|
 Japan | |
| Name | Submarine No. 389 |
| Builder | Mitsubishi, Kobe, Japan |
| Laid down | 17 March 1943 |
| Renamed | Ro-48 on 31 July 1943 |
| Launched | 15 October 1943 |
| Completed | 31 March 1944 |
| Commissioned | 31 March 1944 |
| Fate | Sunk 19 July 1944 |
| Stricken | 10 October 1944 |
| General characteristics | |
| Class and type | Kaichū type submarine (K6 subclass) |
| Displacement |
|
| Length | 80.5 m (264 ft 1 in) overall |
| Beam | 7 m (23 ft 0 in) |
| Draft | 4.07 m (13 ft 4 in) |
| Installed power |
|
| Propulsion |
|
| Speed |
|
| Range |
|
| Test depth | 80 m (260 ft) |
| Crew | 61 |
| Armament |
|
Design and description
The submarines of the K6 sub-class were versions of the preceding K5 sub-class with greater range and diving depth.[1] They displaced 1,133 tonnes (1,115 long tons) surfaced and 1,470 tonnes (1,447 long tons) submerged. The submarines were 80.5 meters (264 ft 1 in) long, had a beam of 7 meters (23 ft 0 in) and a draft of 4.07 meters (13 ft 4 in). They had a diving depth of 80 meters (260 ft).[2]
For surface running, the boats were powered by two 2,100-brake-horsepower (1,566 kW) diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 600-horsepower (447 kW) electric motor.[3] They could reach 19.75 knots (36.58 km/h; 22.73 mph) on the surface and 8 knots (15 km/h; 9.2 mph) underwater. On the surface, the K6s had a range of 11,000 nautical miles (20,000 km; 13,000 mi) at 12 knots (22 km/h; 14 mph); submerged, they had a range of 45 nmi (83 km; 52 mi) at 5 knots (9.3 km/h; 5.8 mph).[1]
The boats were armed with four internal bow 53.3 cm (21.0 in) torpedo tubes and carried a total of ten torpedoes. They were also armed with a single 76.2 mm (3.00 in) L/40 anti-aircraft gun and two single 25 mm (1.0 in) AA guns.[1]
Construction and commissioning
Ro-48 was laid down at Submarine No. 389 on 17 March 1943 by Mitsubishi at Kobe, Japan.[4] She was renamed Ro-48 on 31 July 1943 and was attached provisionally to the Maizuru Naval District that day.[4] Launched on 15 October 1943,[4] she was completed and commissioned on 31 March 1944.[4] She was completed with a radar detector installed and a modified conning tower designed to be less visible to radar signals.[4]
Service history
March–July 1944
Upon commissioning, Ro-48 was attached formally to the Maizuru Naval District and assigned to Submarine Squadron 11 for workups.[4] She was reassigned to Submarine Division 34 in the 6th Fleet on 3 July 1944.[4]
First war patrol
On 13 June 1944 the Combined Fleet activated Operation A-Go for the defense of the Mariana Islands, and the Battle of Saipan began with U.S. landings on Saipan on 15 June 1944.[4] On 5 July 1944, Ro-48 departed Kure, Japan, to begin her first war patrol, assigned a patrol area in the Marianas off Saipan.[4] She arrived in her patrol area, within 200 nautical miles (370 km; 230 mi) of Saipan, on 12 July 1944, and that date received orders to stand by to rescue Imperial Japanese Navy Air Service pilots stranded on Tinian.[4] While she was 30 nautical miles (56 km; 35 mi) north of Saipan at 21:30 Japan Standard Time on 14 July 1944, her commanding officer reported U.S. forces had forced him to submerge and that he was moving to a new position.[4] On 16 July 1944, 6th Fleet headquarters ordered Ro-48 to return to Japan.[4]
Loss
On 18 July 1944, a United States Navy hunter-killer group centered around the escort aircraft carrier USS Hoggatt Bay (CVE-75) was operating 300 nautical miles (560 km; 350 mi) east of Saipan when Hoggatt Bay′s radar detected an unidentified vessel on the surface at a range of 21,000 yards (19,200 m).[4] At 00:24 on 19 July 1944, two destroyer escorts — USS Wyman (DE-38) and USS Reynolds (DE-42) — detached from the Hoggatt Bay group to investigate.[4] Wyman held radar contact on the vessel until 00:46, when the contact disappeared at a range of 4,000 yards (3,700 m), indicating a submerging submarine.[4] Wyman then established sonar contact on the submarine at a range of 1,600 yards (1,500 m).[4] She fired a barrage of 24 Hedgehog projectiles at 00:51, but did not score a hit.[4] Wyman then opened the range to reload before closing for another attack, and fired a second 24-projectile Hedgehog barrage at 01:25.[4] Five underwater explosions that shook Wyman ensued as the Hedgehog projectiles struck the submarine and tore it apart.[4] Wyman subsequently lost sonar contact and could not regain it, indicating destruction of the submarine at 13°01′N 151°58′E.[4]
The submarine Wyman sank probably was Ro-48.[4] On 10 July 1944, the Imperial Japanese Navy declared Ro-48 to be presumed lost off Saipan with all 76 men on board.[4] She was stricken from the Navy list on 10 October 1944.[4]
Some sources have credited the fast transport USS Gilmer (APD-11) and the destroyer escort USS William C. Miller (DE-259) with sinking Ro-48 on 14 July 1944, but the Japanese submarine they sank was probably I-55.[4]
Notes
- Carpenter & Dorr, p. 124
- Bagnasco, p. 187
- Chesneau, p. 203
- Hackett, Bob; Kingsepp, Sander (2017). "IJN Submarine RO-48: Tabular Record of Movement". combinedfleet.com. Retrieved 24 September 2020.
References
- Bagnasco, Erminio (1977). Submarines of World War Two. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-962-6.
- Carpenter, Dorr B. & Polmar, Norman (1986). Submarines of the Imperial Japanese Navy 1904–1945. London: Conway Maritime Press. ISBN 0-85177-396-6.
- Chesneau, Roger, ed. (1980). Conway's All the World's Fighting Ships 1922–1946. Greenwich, UK: Conway Maritime Press. ISBN 0-85177-146-7.
- Hackett, Bob; Kingsepp, Sander (2017). "IJN Submarine RO-48: Tabular Record of Movement". SENSUIKAN! Stories and Battle Histories of the IJN's Submarines. Combinedfleet.com. Retrieved 24 September 2020.
- Hackett, Bob; Sander Kingsepp (2003). "Kaichu Type". Sensuikan!. Combinedfleet.com. Retrieved 20 September 2020.
- Hashimoto, Mochitsura (1954). Sunk: The Story of the Japanese Submarine Fleet 1942 – 1945. Colegrave, E.H.M. (translator). London: Cassell and Company. ASIN B000QSM3L0.
