Japanese submarine Ro-102

History
Empire of Japan
Name:	Ro-102
Builder:	Kawasaki Jyuko
Laid down:	30 September 1941
Launched:	17 April 1942
Completed:	29 July 1942
Fate:	Sunk, 1943
General characteristics
Class and type:	Ro-100-class submarine
Displacement:	611 tonnes (601 long tons) surfaced 795 tonnes (782 long tons) submerged
Length:	60.90 m (199 ft 10 in) overall
Beam:	6.00 m (19 ft 8 in)
Draft:	3.51 m (11 ft 6 in)
Installed power:	1,000 bhp (750 kW) (diesel) 760 hp (570 kW) (electric motor)
Propulsion:	Diesel-electric 1 × diesel engine 1 × electric motor
Speed:	14.2 knots (26.3 km/h; 16.3 mph) surfaced 8 knots (15 km/h; 9.2 mph) submerged
Range:	3,500 nmi (6,500 km; 4,000 mi) at 12 knots (22 km/h; 14 mph) surfaced 60 nmi (110 km; 69 mi) at 3 knots (5.6 km/h; 3.5 mph) submerged
Test depth:	75 m (246 ft)
Crew:	38
Armament:	4 × bow 533 mm (21 in) torpedo tubes 2 × 25 mm (1 in) Type 96 anti-aircraft guns or 1 × 76 mm (3 in) AA gun

The Japanese submarine Ro-102 was a Ro-100-class submarine built for the Imperial Japanese Navy during World War II.

Design and description

The Ro-100 class was a medium-sized, coastal submarine derived from the preceding Kaichū type. They displaced 611 tonnes (601 long tons) surfaced and 795 tonnes (782 long tons) submerged. The submarines were 60.9 meters (199 ft 10 in) long, had a beam of 6 meters (19 ft 8 in) and a draft of 3.51 meters (11 ft 6 in). They had a double hull and a diving depth of 75 meters (246 ft).^[1]

For surface running, the boats were powered by two 500-brake-horsepower (373 kW) diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 380-horsepower (283 kW) electric motor. They could reach 14.2 knots (26.3 km/h; 16.3 mph) on the surface and 8 knots (15 km/h; 9.2 mph) underwater. On the surface, the Ro-100s had a range of 3,500 nautical miles (6,500 km; 4,000 mi) at 12 knots (22 km/h; 14 mph); submerged, they had a range of 60 nmi (110 km; 69 mi) at 3 knots (5.6 km/h; 3.5 mph).^[2]

The boats were armed with four internal bow 53.3 cm (21.0 in) torpedo tubes and carried a total of eight torpedoes. They were also armed with two single mounts for 25 mm (1 in) Type 96 anti-aircraft guns or a single 76 mm (3 in) AA gun.^[3]

Construction and career

Laid down at the Kawasaki Jyuko on 30 September 1941 and launched on 17 April 1942. Completed on 29 July 1942. Ro-102 was lost after May 1943 whilst on patrol south of New Guinea. Motor Torpedo Boats PT-150 and PT-152 were credited with her loss off Lae, New Guinea on 13/14 May 1943, however this was confirmed later as I-6, which survived the encounter.

Notes

1. Carpenter & Dorr, p. 123
2. Chesneau, p. 204
3. Bagnasco, p. 193

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 (2013). "IJN Submarine RO-102: Tabular Record of Movement". SENSUIKAN! Stories and Battle Histories of the IJN's Submarines. Combinedfleet.com. Retrieved 18 August 2015.