No.1-class landing ship

Landing Ship No. 4 on 22 June 1944
Class overview
Name:	No.1-class landing ship
Builders:	Kure Naval Arsenal Mitsubishi Heavy Industries
Operators:	Imperial Japanese Navy Republic of China Navy
Preceded by:	No.1-class patrol boat
Cost:	6,912,000 JPY as first ordered 22 vessels 7,126,000 JPY as second ordered 12 vessels
Built:	1943–1945
In commission:	1944–1950
Planned:	34
Completed:	21
Cancelled:	13
Lost:	16
Retired:	5
General characteristics
Type:	Landing assault ship
Displacement:	1,500 long tons (1,524 t) standard 1,800 long tons (1,829 t) trial
Length:	96.0 m (315 ft 0 in) overall 94.0 m (308 ft 5 in) waterline
Beam:	10.2 m (33 ft 6 in)
Draught:	3.6 m (11 ft 10 in)
Draft:	6.5 m (21 ft 4 in)
Propulsion:	1 × Kampon geared turbine 2 × Kampon water tube boilers single shaft, 9,500 shp
Speed:	22 knots (25 mph; 41 km/h)
Range:	3,700 nmi (6,900 km) at 18 kn (21 mph; 33 km/h)
Capacity:	Example 1: 4 × Daihatsu and 260 tons freight Example 2: 7 × Type 2 Ka-Mi Example 3: 2 × Kō-hyōteki Example 4: 6 × Kaiten or Kairyū
Complement:	148
Sensors and processing systems:	as built 1 × Type 22 radar 1 × Type 93 hydrophone 1 × Type 93 active sonar later fitted 1 × Type 13 radar
Armament:	Landing ship No.1 as built 2 × 127 mm (5.0 in) L/40 AA guns 15 × Type 96 25 mm AA guns 18 × depth charges

The No.1-class landing ship (第一号型輸送艦,, Dai 1 Gō-gata Yusōkan) was a class of amphibious assault ships of the Imperial Japanese Navy (IJN), serving during and after World War II. The IJN also called them 1st class transporter (一等輸送艦,, 1-Tō Yusōkan).

Background

• The IJN lost too many destroyers while employed as transporters ("Tokyo Express") in the Guadalcanal Campaign.
• Therefore, the IJN wanted the enforced transporter which could penetrate the front line. It was realized rapidly after Operation Ke.

Design

• In April 1943, the General Staff requested a high-speed military transporter to the Technical Department. The requirements were as follows:
  • Displacement: 1,250 long tons (1,270 t) standard
  • Propulsion: 1 × geared turbine, 2 × boilers, single shaft
  • Speed: 23 knots (26 mph; 43 km/h)
  • Range: 3,500 nmi (6,500 km) at 18 kn (21 mph; 33 km/h)
  • Capacity: 2 × Landing craft (Daihatsu) and 200 tons freight
  • Armament: 2 × 127 mm (5.0 in) or 120 mm (4.7 in) AA guns, 9 × 25 mm AA guns and 36 × depth charges
• The General Staff thought it was possible to use a variant of the Matsu-class destroyer for this plan, because they aimed to utilise mass production. In this original plan, the requirement for a slope was not considered. They thought about a Japanese version of the High speed transport (APD).
• The Technical Department, however, did not agree with this plan. They submitted a more aggressive plan to the General Staff. They increased the number of landing craft carried and with the effect of reducing the time for landing operations.
• In addition, about the mass production effect, they intended to deal with this by reducing the shipyards being used for production.
• At that time, the stern slope and operating ability of the amphibious tanks were added.
• In September 1943, the Kure Naval Arsenal finished the detailed design. Her project number was J37.

Construction

• The IJN nominated Kure Naval Arsenal as the main builder and Mitsubishi Heavy Industries as support builder.
• Lead ship (Landing ship No.1) was constructed at Mitsubishi, laid down on 5 November 1943, launched on 8 February 1944, and completed on 10 May 1944.
• The Kure Naval Arsenal completed 15 vessels, Mitsubishi completed 6 vessels.
• The Kure Naval Arsenal was earnest. They made the original sized wooden samples, and learned a work procedure. They used the Yamato's dock and repeated build 2 vessels at the same time. Therefore, most of Kure's vessels were completed within 80 days from being laid down.
• The completed vessels were sent one by one to the front.

Service

• Their primary role was that of a transporter, however since their armaments were strong they were useful as multi-purpose ships at the front, functioning as transporters, as minelayers and as escort ships.
• Most of these vessels were sent to the Battle of Leyte and transportation duty of the Bonin Islands. By that time, the IJN already lost air superiority and thalassocracy (naval superiority) in those areas and these vessels suffered heavy losses.
• 5 vessels survived war and were surrendered to the Allies.

Ships in class

Photos

• 

  Landing Ship No. 5 w/ Kō-hyōteki No. 69 on 17 August 1944

• 

  Landing Ship No. 1 class in action

• 

  Landing Ship No. 11 at San Isidro

See also

• High speed transport
• No.1-class patrol boat
• No.31-class patrol boat
• No.101-class landing ship

References

1. ↑ "Japanese Escorts". Combinedfleet.com. Retrieved 2 April 2013. 

Bibliography

• "Rekishi Gunzō". , History of Pacific War Vol.37, "Support vessels of the Imperial Japanese Forces", Gakken (Japan), June 2002, ISBN 4-05-602780-3
• Rekishi Gunzō, History of Pacific War Vol.51, "The truth histories of the Imperial Japanese Vessels Part.2", Gakken (Japan), August 2005, ISBN 4-05-604083-4
• The Maru Special, Japanese Naval Vessels No.50, "Japanese minesweepers and landing ships", Ushio Shobō (Japan), April 1981
• Ships of the World special issue Vol.47, Auxiliary Vessels of the Imperial Japanese Navy, "Kaijinsha". , (Japan), March 1997
• Senshi Sōsho Vol.88, Naval armaments and war preparation (2), "And after the outbreak of war", Asagumo Simbun (Japan), October 1975
• Shizuo Fukui, FUKUI SHIZUO COLLECTION "Japanese Naval Vessels 1869–1945", KK Bestsellers (Japan), December 1994