View source for Type A1 submarine

{|{{Infobox ship begin
}}
{{Infobox ship image
| Ship image = Japanese submarine I-10 at Penang port in 1942.jpg
| Ship caption = ''I-10'' in [[Penang]], 1942
}}
{{Infobox ship class overview
|Name=
|Builders=
|Operators={{navy|Empire of Japan}}
|Class before=[[Junsen type submarine#Junsen III (I-7 class)|Type J3 submarine]]
|Class after=[[Type A2 submarine]]
|Cost=
|Built range=1939–1942
|In service range= 1941–1944
|In commission range= 
|Total ships planned=5
|Total ships completed=3
|Total ships cancelled=2
|Total ships lost=3
}}
{{Infobox ship characteristics
| Hide header = 
| Header caption = 
| Ship type = [[Cruiser submarine]]
| Ship displacement = *{{Cvt|2919|LT|t|0|disp=flip|lk=on}} (surfaced)
*{{Cvt|4129|LT|t|0|disp=flip}} (submerged)
| Ship length = {{convert|113.7|m|ft|0|abbr=on}} ([[o/a]])
| Ship beam = {{convert|9.5|m|ftin|abbr=on}}
| Ship draft = {{convert|5.3|m|ftin|abbr=on}}
| Ship power = *{{cvt|12400|bhp|lk=on}} (diesel)
*{{convert|2400|shp|abbr=on}} ([[electric motor]])
| Ship propulsion = *[[Diesel-electric]]
*2 × [[diesel engine]]s
*2 × electric motors
| Ship speed = *{{convert|23.5|kn|lk=in}} (surfaced)
*{{convert|8|kn}} (submerged)
| Ship range = *{{convert|16000|nmi|abbr=on|lk=in}} at {{convert|16|kn}} (surfaced)
*{{convert|60|nmi|abbr=on}} at {{convert|3|kn}} (submerged)
| Ship crew = 100
| Ship test depth = {{convert|100|m|ft|abbr=on}}
| Ship armament = *6 × bow {{convert|533|mm|in|0|abbr=on}} [[torpedo tubes]]
*1 × [[14 cm/40 11th Year Type naval gun|{{convert|14|cm|in|1|abbr=on}}]] [[deck gun]]
*2 × twin [[Type 96 25 mm AT/AA Gun|{{convert|25|mm|in|0|abbr=on}}]]  [[AA gun]]s
| Ship aircraft = 1 × [[Yokosuka E14Y]] seaplane
| Ship aircraft facilities = 1 × [[Aircraft catapult|catapult]]
| Ship notes = 
}}
|}

The {{nihongo|'''Type A1 submarine'''|巡潜甲型潜水艦|Junsen kō-gata sensuikan, "Cruiser submarine type A"}}, also called {{nihongo|'''I-9-class submarine'''|伊九型潜水艦|I-kyū-gata sensuikan}} were a trio of aircraft-carrying [[cruiser submarine]]s built for the [[Imperial Japanese Navy]] (IJN) during the 1930s. All three participated in the Pacific War and were lost.

==Design and description==
The submarines of the A1 type were versions of the preceding [[Type J3 submarine|J3 class]] with superior range, improved aircraft installation. Unlike the earlier boats, they were equipped with extensive communication facilities to allow them to serve as squadron [[flagship]]s.<ref name=b4/> They [[Displacement (ship)|displaced]] {{Convert|2919|LT|t|0|disp=flip|lk=on|sp=us}} surfaced and {{Cvt|4129|LT|t|0|disp=flip}} submerged. The submarines were {{convert|113.7|m|ft|0|sp=us}} long, had a [[beam (nautical)|beam]] of {{convert|9.5|m|ftin|sp=us}} and a [[draft (hull)|draft]] of {{convert|5.3|m|ftin|sp=us}}. They had a diving depth of {{convert|100|m|ft|sp=us}}.<ref name=b4>Bagnasco, p. 188</ref>

For surface running, the boats were powered by two {{convert|6200|bhp|lk=in|0|adj=on}} [[diesel engine]]s, each driving one [[propeller shaft]]. When submerged each propeller was driven by a {{convert|1200|hp|0|adj=on}} [[electric motor]]. They could reach {{convert|19|kn|lk=in}} on the surface<ref name=c5>Chesneau, p. 200</ref> and {{convert|8.25|kn}} underwater. On the surface, the A1s had a range of {{convert|16000|nmi|lk=in}} at {{convert|16|kn}}; submerged, they had a range of {{convert|90|nmi|abbr=on}} at {{convert|3|kn}}.<ref name=cd3/>

The boats were armed with six internal bow {{convert|53.3|cm|in|0|abbr=on|sp=us}} [[torpedo tube]]s and carried a total of 18 [[torpedo]]es. They were also armed with a single 40-caliber [[14 cm/40 11th Year Type naval gun|{{convert|140|mm|in|abbr=on}}]] [[deck gun]] and two twin [[Type 96 25 mm AT/AA Gun|{{convert|25|mm|in|0|abbr=on}} Type 96]] [[anti-aircraft gun]]s.<ref name=cd3>Carpenter & Dorr, p. 101</ref>

Unlike the J3 class, the aircraft [[hangar]] was integrated into the [[conning tower]] and faces forward; the positions of the deck gun and the [[Aircraft catapult|catapult]] were exchanged so the aircraft could use the forward motion of the ship to supplement the speed imparted by the catapult. The hangar could be accessed from inside the [[pressure hull]] and the [[floatplane]] was stowed with its wings folded.<ref name=cd3/>

==Boats==
* {{ship|Japanese submarine|I-9||2}} was sunk by destroyer [[USS Frazier (DD-607)|USS ''Frazier'']] in the [[Aleutians]] on 11 June 1943.
* {{ship|Japanese submarine|I-10||2}} was sunk by destroyer [[USS David W. Taylor (DD-551)|USS ''David W. Taylor'']] and destroyer escort [[USS Riddle (DE-185)|USS ''Riddle'']] east of Saipan on 4 July 1944.
* {{ship|Japanese submarine|I-11||2}} disappeared south of Funafuti after 11 January 1944. The ''I-11'' probably struck a mine laid by [[USS Terror (CM-5)|USS ''Terror'']].
Two more boats were ordered under the [[Modified 5th Naval Armaments Supplement Programme|1942 Naval Program]], but were later cancelled.<ref name=b4/>

==Notes==
{{Reflist|30em}}

==References==
*{{cite book|last=Bagnasco |first=Erminio |title=Submarines of World War Two |year=1977 |publisher=Naval Institute Press |location=Annapolis, Maryland |isbn=0-87021-962-6}}
*{{cite book|last1=Boyd|first1=Carl|last2=Yoshida|first2=Akikiko|title=The Japanese Submarine Force and World War II|date=2002|publisher=Naval Institute Press|location=Annapolis, Maryland|isbn=1-55750-015-0|name-list-style=amp}}
*{{cite book|last1=Carpenter|first1=Dorr B.|last2=Polmar|first2=Norman|title=Submarines of the Imperial Japanese Navy 1904–1945|year=1986|publisher=Conway Maritime Press|location=London|isbn=0-85177-396-6|name-list-style=amp}}
*{{cite book|title=Conway's All the World's Fighting Ships 1922–1946|editor1-last=Chesneau|editor1-first=Roger|publisher=Conway Maritime Press|location=Greenwich, UK|year=1980|isbn=0-85177-146-7}}
*{{cite book|last=Hashimoto|first=Mochitsura|others=Colegrave, E.H.M. (translator)|title=Sunk: The Story of the Japanese Submarine Fleet 1942 – 1945|publisher=Cassell and Company|location=London|year=1954|id=ASIN B000QSM3L0}}
*{{cite book|last=Stille|first=Mark|title=Imperial Japanese Navy Submarines 1941-45| series =New Vanguard|volume=135|year=2007|publisher=Osprey Publishing|location=Botley, Oxford, UK|isbn=978-1-84603-090-1}}
{{Type A submarine}}

[[Category:Submarine classes]]
[[Category:Type A1 submarines| ]]
[[Category:Submarine aircraft carriers]]