Torpedo
Aircraft
- 'Kate'
Nakajima B5N - Allied reporting-name
"Kate" - was the sole shipborne torpedo-bomber of the Japanese Navy at
the start of the Pacific War. It was by then quite old, having been designed
to meet a specification of 1935, and was already judged to be obsolescent.
However, when first put into production it had been a very advanced aircraft,
and in war it out-performed any Allied shipborne torpedo-plane until the
arrival of the Grumman Avenger in mid-1942. In particular it was greatly
superior to the Douglas TBD Devastator - the carrier-borne torpedo-plane
of the US Fleet at the important Battles of Coral Sea and the decisive
Battle of Midway.
B5Ns played the main role in sinking the carrier Lexington at Coral Sea, Yorktown at Midway, and Hornet at the Battle of Santa Cruz in October 1942. Along with the destruction of the carrier Wasp by a Japanese submarine during the Guadalcanal campaign these were the major blows to the American carrier forces in the early phase of the Pacific War. These exploits supplemented the Kate's success in the surprise attack on Pearl Harbor on December 7 1941, in which 40 B5N2s armed with torpedoes - and 103 B5N1s armed with bombs - inflicted enormous damage on the US Battle Fleet.
Total production of the B5N was 1,149. By the time of the Marianas campaign it had been largely replaced by its successor - the Nakajima B6N Tenzan "Jill"- but at the Battle of the Philippine Sea there were 17 Kates in Admiral Ozawa's Mobile Fleet, aboard the light carriers of Division Three.
Nakajima B6N Tenzan - "Jill"
Tenzans went into action for the first time in late 1943, off Bougainville in the Solomon Islands. At the major Battle of the Philippine Sea the air complement of the Mobile Fleet's carriers included some 80 B6Ns. Towards the end of the war some Tenzans were equipped with radar for night torpedo attacks on Allied shipping. Additionally, many Jills were employed in kamikaze attacks on the US fleet, especially during the Okinawa campaign in April and May of 1945.
below - 3-view of Nakajima
B6N Jill
Origin: Nakajima-Nikoki KK
Type: (B5N1) Three-seat carrier-based bomber - (B5N2) Three-seat carrier-based torpedo-bomber
Dimensions: Span 50' 11" - Length 33' 10" - Height 12' 2"
Weight: (B5N1) 4,645 lb empty, 8,047 lb loaded - (B5N2) 5,024 lb empty, 8,378 lb loaded (normal), 9,039 lb loaded (maximum).
Engine: (B5N1) One 770 hp Nakajima Hikari 3 9-Cylinder radial (B5N1 Model 12 ) 970 hp or 985 hp Sakae 11 14-Cylinder 2-row radial.
Performance
Maximum speed (B5N1) 217 mph - (B5N2) 235 mph
Initial climb: 1,378 feet per minute
Service ceiling: Approx 25,000 feet
Range: (B5N1) 683 miles (B6N2 with normal load) 609
miles.
Armament
(B5N1) One 7.7 mm machine-gun, manually-aimed, in rear
cockpit
Underwing racks for two 250 kg bombs or six 60 kg bombs
(B5N2) Twin 7.7 mm machine-guns, manually-aimed, in rear
cockpit
Two 7.7 mm machine-guns, fixed, above forward fuselage
Fuselage rack for one 800 kg (18-inch) torpedo or three 250 kg
bombs
Nakajima B6N Tenzan "Jill"
Origin: Nakajima Hikoki KK
Type: Three-seat carrier-based and land-based torpedo-bomber
Dimensions: Span 48' 10" - Length 35' 8" - Height (B6N1) 12' 2" (B6N2) 12' 6"
Weight: 6,636 lb empty, 11,464 loaded (normal) 12,456 loaded (maximum)
Engine: (B6N1) One 1,870 hp
Nakajima Mamori-11 14-cylinder two-row radial
(B6N2) One 1,850 hp Mitsubishi Kasei-25
14-cylinder two-row radial
Armament
One 7.7 mm machine-gun, manually-aimed,
in rear cockpit
One 7.7 mm machine-gun, manually-aimed
by middle crew member, in rear ventral position
One 800 kg torpedo (18-inch) -
or six 100 kg bombs - under fuselage
Acknowledgments
The above data are mainly derived from
Bill Gunston's 'Combat Aircraft of World War II' (Salamander,
London 1978),
as are the profile views of the B6N Jill
The profile drawing of the B5N is reproduced,
with thanks, from
'Jane's War at Sea 1897-1997 Centennial Edition' (London 1997)
