TheNakajima B5N Allied reporting name
Katherine "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
carrier based torpedo plane until the arrival of the Grumman Avenger
in mid 1942. In particular, it was greatly superior to the Douglas
TBD Devastator the shipboard torpedo plane of the US Fleet at
the crucial battles of Coral Sea and 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 stages
of the War. These exploits supplemented the Kate's success in the
surprise attack on Pearl Harbor, December 7 1941, in which 40 B5N2s
armed with torpedoes and 103 B5N1s armed with bombs crippled 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 still 17 Kates in Admiral Ozawa's
Mobile Fleet, aboard the light carriers of Division Three.
Nakajima B6N Tenzan "Jill"
The B6N was a conventional looking aircraft,
but was in some respects superior to Allied torpedo-aircraft of the
same period. The Tenzan ("Heavenly Mountain") was a slender and clean-lined
machine with no internal weapons bay. The torpedo was carried offset
to the right, with the large oil cooler offset to the other side.
The big Mamori engine of the B6N1, driving a four-blade Hamilton type
propeller, underwent severee vibration and overheating. Although it
was kept in service it was replaced in production by the the B6N2.
The lower power of the older and well tried Kasen engine was compensated
for by improved streamlining, which gave less drag.
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.
Data
Nakajima B5N "Kate"
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 x 7.7 mm machine gun, in rear cockpit
Underwing racks for 2 x 250 kg bombs or 6
x 60 kg bombs
(B5N2) Twin 7.7 mm machine guns, in rear
cockpit
Two x 7.7 mm machine guns, fixed, above forward
fuselage
Fuselage centreline rack for one 800 kg (18-inch)
torpedo or 3 x 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
x 7.7 mm machine gun, rear gunner.
One x 7.7 mm machine gun, middle crew member.
One 800 kg torpedo (18-inch) - or six x 100
kg bombs - under fuselage.
