Nakajima G10N Fugaku, G8N Renzan N-40 "Rita"& Nakajima G5N1 Shinzan(Liz)- strategic heavy bombers.Nakajima G10N - strategic heavy bomber
In April 1943, as a private venture, Nakajima initiated studies for an aircraft (Project Z) capable of carrying out bombing operations against the US mainland from bases in Japan. Later during that year these studies served as the basis for a joint Navy-Army project, which initially was intended to be powered by six 5,000 hp Nakajima Ha-505 thirty-six cylinder radials. However, because of expected late availability of these powerplants, the design was scaled down to use six 2,500 hp Nakajima NK11A radials. In this form the G10N1 Fugaku (Mount Fugi) was designed to cruise at altitudes in excess of 32,810 ft (10,000 m) and to reach a top speed of 423 mph (680 km/h). It remained in development at war's end and never saw operational service. http://en.wikipedia.org/wiki/Nakajima_G10N
From "(FUGAKU)" ,Author:Maema Takanori,Kodansha Tokyo
published in 1991.ISBN4-06-205543-0 C0095 P2000E(0) No.(1)
In November 1942, Chikuhei Nakajima called twenty Nakajima's elite engineers to the Nakajima club, explained that
Japan would lost the war by strategic bombing to Japan using B-29 and B-36 from 1944.(He already knew B-36 at the day!)
The only way to win the war was strategic bombing to the United States by transoceanic large
bomber with 5,000hp engines, which speed was higher than American fighter.
This plan was already explained to the JIJA and IJN.
Study how to realize this bomber as the secret private venture, keep secret.
Named secret study party as “Winning game, guard Japanese sky research party ”, leader was chief engineer Satoshi Koyama.
Then the conceptual design began by the secret party, the chief of fuselage study was Shinobu Mitake (Shinzan chief designer), the chief of engine study was Tanaka Kiyoshi ,Mamori engine and NBD engine chief designer). The engine designing team started discussion between Kotani (Section manager), Tanaka, Nakagawa chief designer of Homare engine), Inoue and Kudo . They discussed about several engine types.
Tanaka and Kudo recommended 4 array 36 cylinder HA54 engine.(tandem double HA44 engine)
BTW Nakagawa argued against this engine that cooling would be the big problem, too risky.
Nakagawa insisted 4,000hp 26 cylinder!!(2 array 13 cylinder) engine which diameter was rather
bigger than HA54. Finally Tanaka and Inoue agreed Nakagawa's plan. The 26 cylinder engine plan
was explained to Chikuhei by Koyama. BTW Chikuhei rejected this 4,000hp engine and ordered to Koyama ”Don't be less than only 1hp from 5,000hp”.
Mitake studied 26 aircraft types based on Chikuhei's idea for the answer of Chikuhei's order.
They were from small plane to large plane, carrier base bomber, torpedo bomber, attack bomber, twin engine bomber, long range bomber, gun ship and cargo plane. At the time, Nakajima's design for the aircraft were based on British R&W report and NACA's report for wing section. Yasuo Naito(Desiger of Saiun's laminar flow wing and past war T-1 trainer) made his own chart for the aircraft basic design from the British R&W report and NACA's report. Naito helped Mitake's study, he thought that among 26 types, the final 3 types were very difficult to design. They were very big long range bomber, gun ship which had 20 cannon located under the fuselage to shoot American fighter and cargo plane to carry soldiers to the United States.
Finally Mitake and Naito merged these 26 types into one long range bomber.
From "(FUGAKU)" ,Author:Maema Takanori , No.(2)
The results of basic design for Z-plane(Final Z-plane) performed by Satoshi Koyama,Yasuo Naito,etc in Nakajima club in 1943/4?1943/6 were as follows.
Wing span:65m, Length:45m, Height:12m, angle of ground position:9 degree?, Wing area:350m2, Maximum wing chord length:9m, Dihedral:3.5 degree, aspect ratio:12, Taper ratio:1:5, angle of incidence:6 degree, horizontal tail stabilizer area:60m2, Vertical tail stabilizer area:40m2,Distance between main wheels:9m, Fuselage fuel tanks capacity;42,720L, Wing fuel tanks capacity:57,200L,
Wing loading:457kg/m2, Power loading:5.3kg/hp, Empty weight:67.3ton, MTOW:160ton, Engine:six double BH(HA54) 5,000hp in take off, 4,600hp/7,000m, Propeller:3 blade contra rotating 4.8m diameter, Maximum speed:680km/h/7,000m, Service ceiling:12,480m, Take off run:1,200m, Range:16000km with 20 ton bomb.
From "(FUGAKU)" ,Author:Maema Takanori, Yoshiro Ikari, No.(6)
In fall of 1943, there were four plans which could bombing the United States. They were Nakajima
Z-plane, Kawanishi TB, Kawasaki Ki-91 and Tachikawa Ki-74?, the IJA and the IJN confused very much. Finally the IJA and IJN Aviation technology committee asked Chikuhei Nakajima to be the chairman of Fugaku committee in 24th of November 1943. In 26th of January 1944, the IJN
held the meeting to compare with Fugaku and TB. The specifications of Fugaku and TB were
as follows.(Source:Ministry of Defense official documents) The IJA held same meeting in 27th of January.
[Fugaku]: Wing span:61m, Wing area:310m2, Range:18,500km with 5ton bomb, Service ceiling:15,000m, Armament:13mm gun×1, 20mm cannon×3, Max speed:700km/h(15,000m), MTOW:116ton, Takeoff run:1,500m, Engine:Nakajima modified six HA219(HA44) ,2340hp in 15,000m.
[TB]: Wing span:52.5m, Wing area:220m2, Range:23,700km with 2ton bomb, Service ceiling:12,000m, Crew:6, Armament:13mm gun×4, Max speed:600km/h(12,000m), MTOW:74ton, Takeoff run:1,900m, Engine:Perhaps Mitsubishi modified four HA214(HA42) or HA211(HA43).
From "(FUGAKU)" ,Author:Maema Takanori Yoshiro Ikari, No.(7)
From January 1944, almost all design managers of Nakajima Aircraft concentrated Fugaku design in parallel with other aircraft design for example Renzan design. The Fugaku design team were consisted of 200 engineers including Mitsubishi and Kawasaki's engineers, 40% engineers were from the IJA and the IJN's aviation technology institute, worked as computers.
In the middle of March 1944, the IJA and IJN joint meeting was held to compare with Fugaku, TB and Ki-74?. Finally Fugaku was selected as the United States bombing aircraft, settled following two plans. HA54 engine was judged too risky. But Nakajima Aircraft kept development of HA54.
[The first plan] Wing area:330m2, Range:18,200km with 10ton bomb, 21,200km with 5ton bomb,Service ceiling:15,000m, Armament:20mm cannon×24, Max speed:640km/h(12,000m), MTOW:122ton, Takeoff run:1,700m, Engine:Nakajima modified six HA219(HA44) ,2500hp in take off, 2,050hp in 7,000?15,000m. Take off run:1,700m. Wing loading:370kg/m2
[The second plan] Wing area:330m2, Range:16,500km with 10ton bomb, 19,400km with 5ton bomb,Service ceiling:15,000m, Armament:20mm cannon×24, Max speed:700km/h(12,000m), MTOW:122ton, Takeoff run:1,200m, Engine:Mitsubishi six HA50, 3300hp in take off, 2,370hp in 10,400m. Take off run:1,200m. Wing loading:370kg/m2
Specifications (Project Z / Fugaku projected)
Crew: 6 to 10
Fugaku: 7 to 8
Length: 44.98 m (147 ft 7 in)
Fugaku: 39.98 m (131 ft)
Wingspan: 64.98 m (213 ft 2 in)
Fugaku: 62.97 m (207 ft)
Height: 8.77 m (28 ft 9 in)
Wing area: 352.01 m2 (3,789.0 sq ft)
Fugaku: 330 m2 (3,552.09 sq ft)
Aspect ratio: 12.1
Empty weight: 65,000 kg (143,300 lb)
Fugaku: 33,800 kg (74,516.24 lb)
Gross weight: 122,000 kg (268,964 lb)
Fugaku: 42,000 kg (92,594.15 lb)
Max takeoff weight: 160,000 kg (352,740 lb)
Fugaku: 70,000 kg (154,323.58 lb)
Powerplant: 6 × Nakajima Ha-54 36-cyl. air-cooled radial piston engines, 3,700 kW (5,000 hp) each at take-off
Fugaku: 6x Nakajima NK11A 18-cyl. air-cooled radial piston engines developing 2,500 hp (1,864 kW) at take-off
Propellers: 6-bladed contra-rotating constant speed propellers, 4.5 m (14 ft 9 in) diameter
Fugaku: 4-bladed constant speed propellers 4.8 m (16 ft) diameter
Maximum speed: 679 km/h (422 mph; 367 kn) at 10,000 m (32,808 ft)
Fugaku: 779 km (484 mi)at 10,000 m (32,808 ft)
Range: 17,999 km (11,184 mi; 9,719 nmi) maximum
Fugaku: 19,400 km (12,055 mi)
Service ceiling: 15,000 m (49,213 ft)
Wing loading: 456.99 kg/m2 (93.60 lb/sq ft)
Fugaku: 211.89 m² (43.4 lb/ft²)
Power/mass: 0.103 kW/kg (0.063 hp/lb)
Fugaku: 0.118 kW/kg (0.07 hp/lb)
Guns: 4× 20mm Type 99 cannon
Bombs: 20,000 kg (44,092 lb) of bombs
It's very difficult to find precise Fugaku variant drawings,also base design,too.
Almost drawings were lost.
Base design : Nakajima HA54 engine(5,000hp in take off) ×6
Variant 1 : Nakajima HA44 engine(2,500hp in take off) ×6
Variant 2 : Mitsubishi HA50 engine(3,000hp in take off) ×6
Variant 3 : Kawanishi designhttp://ww2drawings.jexiste.fr/Files/2-Airplanes/Axis/3-Japan/04-Bombers/G10N1-Fugaku/G10N1-Fugaku.htmBrief history of Project Z/Nakajima G10N Fugaku :
(1) 1943/1/28 : 4 engine and 6 engine large bomber plan(including gun ship variant and cargo variant) was made by Nakajima aircraft
private venture.(Engine was HA177,Mamori engine variant? Take off power is unknown.)
(2) 1943/2/16 : 4 engine and 6 engine large bomber plan was made by Nakajima aircraft private venture.(Engine was double BH(HA54),take off power was 4,400hp each.)
(3) 1943/3/5 : Temporary 6 engine(HA44,take off power was 2,600hp each) bomber plan(including cargo
variant) was made by Nakajima aircraft.
(4) 1943/4 1943/6 : Basic design for Z-plane was performed by Satoshi Koyama,Yasuo Naito,etc
in Nakajima club.
(5) 1943/6/8 : 'Z-plane design explanation' was made by Nakajima aircraft.(final Z-plane plan)
(6) 1943/8 : 'Winning strategy or Winning game plan' was made by Chikuhei Nakajima.
(7) 1943/9 : Z-plane was selected as IJN and IJA joint research program, IJN insisted that service
ceiling was 15,000m with light armament, IJA insisted that service ceiling was 10,000
with heavy armament. Finally IJN's plan was selected with range was
(8.) 1944/1 : IJN and IJA compared with Fugaku and Kawanishi TB, selected Fugaku, although JJN
(9) 1944/1 : Named this plane as Fugaku. Established Fugaku committee, chairman was
Chikuhei Nakajima, members were Kugisho, IJA aircraft technology research institute,
Central aircraft research institute, Tokyo imperial university, Nakajima Aircraft,
Mitsubishi Aircraft, Sumitomo Metal and Hitachi.
(10) 1944/3/14 : Fugaku committee offered to IJN and IJA following two stage developing plan for
Fugaku because of the delay of HA54 development.
Realize HA44 engine×6 bomber.
Realize HA54 engine×4 bomber or HA50 engine×6 bomber.
(11) 1944/8 : IJN and IJA stopped Fugaku project followed the fall of Saipan island .
Nakajima G8N Renzan N-40 "Rita"
The Nakajima G8N Renzan ("Mountain Range") was a four-engine long-range bomber designed for use by the Imperial Japanese Navy. The Navy designation was "Type 18 land-based attack aircraft"; the Allied code name was "Rita".
In February 1943 the Imperial Navy staff asked Nakajima Aircraft Company to design a four-engined bomber, capable of meeting an earlier specification set for a long-range land-based attack plane. The final specification, issued on 14 September 1943, called for a plane with a maximum speed of 320 knots (370 mph; 590 km/h) able to carry a 4,000 kg (8,800 lb) bomb-load 2,000 nmi (3,700 km; 2,300 mi) or a reduced bomb-load 4,000 nmi (7,400 km; 4,600 mi).
Nakajima's design featured a mid-mounted wing of small area and high aspect ratio, a tricycle landing gear and a large single-fin rudder. Power came from four 2,000 hp Nakajima NK9K-L "Homare" 24 radial engines with Hitachi 92 turbosuperchargers driving four-bladed propellers. The engines were cooled by counter-rotating fans positioned just inside the engine cowlings. Defensive armament included power-operated nose, dorsal, ventral and tail turrets along with two free-swiveling machine guns at the beam positions.
A captured G8N with a C-45 and T-6
The initial prototype was completed in October 1944 and delivered to the Navy for testing in January 1945, a mere one year after the Navy ordered development to start. Three further examples were completed by June 1945, with the third prototype being destroyed on the ground by US carrier aircraft.
Other than minor problems with the turbosuperchargers, the Renzan performed satisfactorily and the Navy hoped to have a total of 16 prototypes and 48 production-version G8N1s assembled by September 1945. But the worsening war situation and a critical shortage of light aluminum alloys led to the project's cancellation in June.
One proposed variant was the G8N2 Renzan-Kai Model 22, powered by four 2,200 hp Mitsubishi MK9A radial engines and modified to accept attachment of the air-launched Ohka Type 33 Special Attack Bomber.
Just prior to Japan's surrender in August 1945 consideration was also briefly given to producing an all-steel version of the aircraft, to be designated G8N3 Renzan-Kai Model 23, but the cessation of hostilities precluded any further development.
After the war, one prototype was taken to the United States and scrapped after testing. None are in existence today.
G8N1 : Four-engine heavy bomber. Production version.
G8N2 : Modified to carry Ohka Type 33 Special Attack Bomber. Four Mitsubishi MK9A radial engines.
G8N3 : All-steel airframe.
Imperial Japanese Navy Air ServiceSpecifications Nakajima G8N
Role Heavy bomber
Manufacturer Nakajima Aircraft Company
First flight 23. October 1944
Primary user IJN Air Service
Length: 22.94 m (75 ft 3 in)
Wingspan: 32.54 m (106 ft 9 in)
Height: 7.20 m (23 ft 7 in)
Wing area: 112 m² (1,205 ft²)
Empty weight: 17,400 kg (38,400 lb)
Loaded weight: 26,800 kg (59,100 lb)
Max. takeoff weight: 32,150 kg (70,900 lb)
Powerplant: 4 × Nakajima NK9K-L Homare 24 18-cylinder radial engines, 1,491 kW (2,000 hp) each
Maximum speed: 576 km/h (358 mph)
Range: 7,250 km (4,500 miles)
Service ceiling: 10,200 m (33,500 ft)
Rate of climb: 457 m/min (1,500 ft/min)
Wing loading: 239 kg/m² (49 lb/ft²)
Power/mass: 0.22 kW/kg (0.14 hp/lb)
2× 20 mm Type 99 cannon in each dorsal, ventral, and tail turrets
2× 13.2 mm (.51 in) Type 2 machine guns in nose turret
2× 13.2 mm (.51 in) Type 2 machine gun in fuselage sides
Up to 4,000 kg (8,818 lb) of bombshttp://en.wikipedia.org/wiki/Nakajima_G8N3D drawing:http://commons.wikimedia.org/wiki/File:Nakajima_G8N1_Renzan_-_3D_drawing.svgNakajima G8N1 Renzan Attack Bomber Test Flight:http://www.youtube.com/watch?v=pmj9Dw8UlTsCockpit:http://www.flickr.com/photos/sdasmarchives/7586030858/in/photostream/http://www.flickr.com/photos/sdasmarchives/7586031218/in/photostream/http://www.flickr.com/photos/sdasmarchives/7586031656/in/photostream/http://www.flickr.com/photos/sdasmarchives/7586031350/in/photostream/
Nakajima G5N1 Shinzan(Liz)
Aircraft History and Specification
In 1938, with success of the Mitsubishi G4M attack bomber, the Japanese Navy issued requirement for an advanced four-engine heavy bomber which could operate more long-range and bomb load than the G4M. Nakajima and Kawanishi were selected to create two new bombers, one was the land-based airplane and the other was flying boat. Kawanishi agreed to tackle the flying boat that became H8K Emily, and Nakajima took the land-based bomber that led to the G5N Shinzan program. The G5N Shinzan was the first Japanese largest aircraft ever built. The Japanese Army also interested in this heavy bomber. The Army owned Douglas DC-4E was hand-overed to Nakajima for both the Navy G5N and Army Ki-68 programs start. Nakajima engineers took the wings, landing gears and powerplant installation from the DC-4E to complete the G5N1 prototype. The first prototype made its first flight in 1942. Performance was disappointing as the DC-4E. Totally six prototypes were completed. Four prototypes were converted to G5N-2 transport airplane. Due to the lack of experience with large aircraft development, the G5N program was cancelled in 1944.http://www.ijnafphotos.com/jbwg5n1.htmSpecifications G5N1
Type: Long-range heavy attack bomber
Purpose: To build an aircraft capable more than 3500km range and 3000kg load.
Engine: 4x NK7A Nakajima Mamoru radial engine
Max.speed: 392 km/h
Armament: 2x 20mm cannon / 4x 7.7mm machine gun / 3200 kg bomb load
Crew: 7 (G5N1/2), 6 (G5N2-L)
Length: 31.02 m (101 ft 9 in)
Wingspan: 42.12 m (138 ft 2 in)
Height: 8.8 m (27 ft 6 in)
Wing area: 201.8 m² (2,171.37 ft²)
Empty weight: 20,100 kg (44,300 lb)
Loaded weight: 28,150 kg (62,060 lb)
Max. takeoff weight: 32,000 kg (70,528 lb)
Powerplant: 4 × Nakajima NK7A "Mamori-11" 14-cylinder air-cooled radial Sumitomo/Hamilton four-blade constant-speed, 1395 kW (1870 hp) each
Maximum speed: 420 km/h (227 kn, 261 mph)
Cruise speed: 278 km/h (150 kn, 173 mph, G5N1)
Range: 4,260 km (2,302 nmi, 2,648 mi)
Service ceiling: 7,450 m (24,442 ft)
2× 20 mm Type 99 cannons
4× 7.7 mm (0.303 in) Type 92 machine guns
2,000-4,000 kg (4,408-8,816 lb) bombs or torpedoes
2× 1,500 kg torpedoes
2× 1,500 kg bombs
4× 800 kg bombs
12× 250 kg bombs
24× 60 kg bombs
4,000 kg freight (G5N2-L)