NAVYPEDIA

Photo

Formidable 1946

Ships

Name	No	Yard No	Builder	Laid down	Launched	Comp	Fate
Illustrious	87, 1948- R2, 1949- R87	732	Vickers-Armstrong, Barrow	27.4.1937	5.4.1939	25.5.1940	stricken 11.1956
Formidable	67, 1948- R1, 1949- R67	1007	Harland & Wolff, Belfast	17.6.1937	17.8.1939	24.11.1940	stricken 11.1953
Victorious	38, 1948- R23, 1949- R38	11	Vickers-Armstrong, Tyne	4.5.1937	14.9.1939	15.5.1941	stricken 3.1968

Technical data

Data variant	as completed	Victorious, 1958 modernization
Displacement standard, t	23000	30530
Displacement full, t	28620 (29110 - 29240 service)	35500
Length, m	205.1 pp 229.6 oa	225.5 pp 238.0 oa
Breadth, m	29.2 w 32.5 oa	31.5 wl 47.8 fd
Draught, m	8.69 normal	9.50
No of shafts	3	3
Machinery	3 sets Parsons geared steam turbines, 6 Admiralty 3-drum boilers	3 sets Parsons geared steam turbines, 6 Foster Wheeler boilers
Power, h. p.	111000	110000
Max speed, kts	30.5	31
Fuel, t	4840 oil	6000
Endurance, nm(kts)	9250(14)	10000(20)
Armour, mm	belt: 114, hangar sides: 114,  bulkheads: 114 - 64, flight deck: 76	belt: 102, hangar sides: 102, flight deck: 76, hangar deck: 51
Armament	Illustrious: 8 x 2 - 114/45 QF Mk III, 6 x 8 - 40/39 2pdr QF Mk VIII, 33 aircraft (Sea Gladiator, Roc fighters, Skua diving bombers, Swordfish, Albacore torpedo bombers, Walrus flying boats) Formidable: 8 x 2 - 114/45 QF Mk III, 6 x 8 - 40/39 2pdr QF Mk VIII, 33 aircraft (Sea Gladiator, Fulmar, Martlet fighters, Skua diving bombers, Swordfish, Albacore torpedo bombers, Walrus flying boats) Victorious: 8 x 2 - 114/45 QF Mk III, 6 x 8 - 40/39 2pdr QF Mk VIII, 33 aircraft (Fulmar, Sea Hurricane, Buffalo, Martlet fighters, Swordfish, Albacore torpedo bombers, Walrus flying boats)	6 x 2 - 76/50 Mk 33, 1 x 6 - 40/60 Mk 6, 36 aircraft (Sea Hawk, Sea Venom fighters, Wyvern torpedo bombers, Skyraider attackers, Gannet, Avenger early warning planes, Whirlwind, Sycamore helicopters)
Electronic equipment	Illustrious: type 79 radar Formidable: type 279 radar Victorious: type 79B radar	type 262, type 963, type 984, type 974, type 293Q, 3x Mk 34 radars
Complement	1229, up to 1997 later	2400

Air group

Year	Fighters	Torpedo bombers / attackers	Rescue planes / asw planes	Helicopters
4.1940 Illustrious	15 Fulmar	18 Swordfish	---
11/1940 Illustrious	12 Fulmar, 2 Sea Gladiator	24 Swordfish	---
11.1940 Formidable	---	21 Albacore	---
2.1941 Formidable	12 Fulmar	21 Albacore	---
3.1941 Illustrious	15 Fulmar, 2 Sea Gladiator	24 Swordfish	---
3.1941 Formidable	13 Fulmar	10 Albacore, 4 Swordfish	---
5.1941 Victorious	6 Fulmar	9 Swordfish	---
7.1941 Victorious	12 Fulmar	30 Albacore	---
8.1941 Victorious	2 Martlet	21 Albacore	---
4.1942 Formidable	16 Martlet	1 Swordfish, 21 Albacore	---
5.1942 Illustrious	1 Fulmar, 20 Martlet	20 Swordfish	---
8.1942 Victorious	18 Fulmar, 6 Sea Hurricane	14 Albacore	---
9.1942 Illustrious	6 Fulmar, 23 Martlet	18 Swordfish	---
10.1942 Victorious	6 Seafire, 12 Wildcat, 6 Sea Hurricane	14 Albacore	---
11.1942 Formidable	6 Seafire, 24 Wildcat	6 Albacore	---
11.1942 Victorious	11 Martlet, 6 Fulmar	21 Albacore, 9 Swordfish	---
1.1943 Victorious	---	15 Avenger	---
2.1943 Victorious	18 Wildcat	---	---
5.1943 Victorious	36 Wildcat	15 Avenger	---
5.1943 Formidable	5 Seafire, 28 Wildcat	12 Albacore	---
7.1943 Illustrious	10 Seafire, 24 Martlet	12 Barracuda	---
9.1943 Illustrious	4 Seafire, 28 Martlet	---	---
9.1943 Formidable	3 Seafire, 15 Wildcat	12 Albacore	---
10.1943 Victorious	36 Wildcat	18 Avenger	---
2.1944 Victorious	14 Corsair	12 Barracuda	---
3.1944 Victorious	14 Corsair	---	---
4.1944 Illustrious	42 Corsair	15 Barracuda	---
4.1944 Victorious	28 Corsair	21 Barracuda	---
5.1944 Illustrious	28 Corsair	21 Barracuda, 18 Avenger	---
7.1944 Illustrious	42 Corsair	9 Barracuda	---
7.1944 Victorious	39 Corsair	---	---
7.1944 Formidable	18 Corsair	24 Barracuda	---
8.1944 Victorious	28 Corsair	21 Barracuda	---
8.1944 Formidable	30 Corsair	24 Barracuda	---
9.1944 Victorious	36 Corsair	12 Barracuda	---
10.1944 Victorious	37 Corsair	---	---
11.1944 Victorious	36 Corsair	19 Avenger	2 Walrus
12.1944 Illustrious	36 Corsair	21 Avenger	---
3.1945 Illustrious	36 Corsair	16 Avenger	---
3.1945 Victorious	37 Hellcat	14 Avenger	---
3.1945 Formidable	36 Corsair	18 Avenger	---
7.1945 Formidable	36 Corsair, 6 Hellcat	12 Avenger	---
8.1945 Victorious	37 Corsair	16 Avenger	2 Walrus
1959 Victorious	10 Sea Venom FAW.21	12 Scimitar F.1	6 Gannet AS.4	---
1963 Victorious	8 Sea Venom FAW.21	8 Buccaneer S.2	5 Gannet AS.4	5 Wessex

Standard scale images

Graphics

Aircraft facilities

: (fd - 5,510 m², ha - 2,638 m² / 12,928 m³); others: (fd - 5,922 m², ha - 2,638 m² / 12,928 m³): Flight deck: 190(Illustrious)/204.2(Victorious, Formidable) (useful length) x29.0 m. Hangar: 139.6x18.9x4.9m. 2 lifts (6.4t, 13.7x6.7m). 1 catapult BH-III (5.4t plane was launched at 122 km/h). Aircraft fuel stowage: 230,000l. Later useful length of flight deck was increased to 229.6m.

Project history

Illustrious by right is considered as significant ship in evolution of aircraft carriers. She had protection of the flight deck for the first time in world practice which considerably raised her battle immunity. Six ships of Illustrious class became the largest class of fleet aircraft carriers of Royal Navy. They were sectioned into 3 groups and had significant differences. First three ships had one level hangar and 3 shafts.

Designing of Illustrious has begun in 1936. Ship should have protection against 500pdr (227kg) bombs and 152mm shells. Standard displacement was limited by 23 000ts as resolved by the London conference of 1936.

Protection was rather strong, 62% of flight deck area was covered by 76mm armour. Increase of battle resistance was paid by 2 times smaller, than on Ark Royal, air group and reduction of freeboard (11.6 m at Illustrious instead of 17.1m at Ark Royal).

The "aerodynamic" form of island and funnel in the form of a profile of a plane wing, and also the round-downs of the deck became feature of architecture of Illustrious: it was supposed, that it will decrease the air turbulence and will improve conditions of take-off and landing of aircrafts. At the same time round-downs shrank deck effective length to 189m, therefore on the subsequent aircraft carriers, since Victorious, round-downs became not so large, that has allowed to extend her deck to 204.2m. The AA armament repeated accepted on Ark Royal, but with new 114mm so-called "inter-decks" mountings.

Ship protection

  Main belt protected about 30% of length by waterline. Main belt amidships was taken to the hangar deck and to the flight deck on the starboard side abreast island. 9m ends of main belt were taken to the upper deck only. Hangar sides were protected on full hangar length. 62% of flight deck (over hangar) had 76mm armour, another part of flight deck was 38mm. Hangar deck had 76 - 64mm thickness between ship sides and hangar sides and 25mm inside citadel. Lower deck was 76mm aft. Lifts were not armoured. There were 38mm anti-torpedo bulkheads. 4.1m deep underwater protection can resist exploding of 340kg TNT.

Modernizations 1.

1941, Illustrious; 11.1941, Formidable: + 10 x 1 - 20/70 Oerlikon Mk II/IV

10/1941, Victorious: + 8 x 1 - 20/70 Oerlikon Mk II/IV

1/1942, Illustrious: - type 79 radar; + type 281 radar

1/1942, Formidable: - type 279 radar; + 2x type 265, type 281 radars

1/1943, Victorious: + 17 x 1 - 20/70 Oerlikon Mk II/IV

4/1943, Victorious: - type 79B radar; + 2 x 4 - 40/56 Bofors Mk 1.2, 2 x 2 - 40/56 Bofors Mk 1.2, 10 x 2 - 20/70 Oerlikon Mk II/IV, type 272, type 277, type 279, type 281B, 6x type 282, type 293 radars

6/1943, Illustrious: - type 281 radar; + 16 x 2 - 20/70 Oerlikon Mk II/IV, 2 x 1 - 20/70 Oerlikon Mk II/IV, type 79B, type 272, type 281B, 6x type 282, type 285 radars

11/1943, Illustrious: useful length of flight deck increased to 225.7m.(fd - 6,545 m², ha - 5,690 m² / 27,878 m³)

4/1944, Formidable: - type 281 radar; + type 79B, type 277, type 281B radars

4/1944, Victorious: - 1 x 8 - 40/39, 10 x 1 - 20/70; + 13 x 2 - 20/70 Oerlikon Mk II/IV

10/1944, Illustrious: - 1 x 8 - 40/39; + 3 x 1 - 40/56 Bofors Mk I/III, 3 x 2 - 20/70 Oerlikon Mk II/IV, 2 x 1 - 20/70 Oerlikon Mk II/IV

end 1944, Formidable + 20 x 2 - 20/70 Oerlikon Mk II/IV, 4 x 1 - 20/70 Oerlikon Mk II/IV

1945, Victorious: - 4 x 2 - 20/70, 2 x 1 - 20/70; + 6 x 1 - 40/56 Bofors Mk I/III

late 1945, Victorious: - 3 x 2 - 20/70 Oerlikon; + 3 x 1 - 40/56 Bofors Mk I/III

1945, Formidable: - 9 x 2 - 20/70, 2 x 1 - 20/70; + 12 x 1 - 40/56 Bofors Mk I/III

1945, Victorious: + SG radar

1.1946, Illustrious: 8 x 2 - 114/45 Mk IIBD, 3 x 1 - 40/60 Mk III, 5 x 8 - 40/39 Mk VIA, 19 x 2 - 20/70 Mk V, 14 x 1 - 20/70 Mk III, 33 aircraft, type 79B, type 272, type 281B, 6x type 282, type 285 radars

1.1946, Formidable: 8 x 2 - 114/45 Mk IIBD, 12 x 1 - 40/60 Mk III, 6 x 8 - 40/39 Mk VIA, 11 x 2 - 20/70 Mk V, 12 x 1 - 20/70 Mk III, 33 aircraft, type 79B, 2x type 265, type 272, type 277, type 281B, type 293 radars

1.1946, Victorious: 8 x 2 - 114/45 Mk IIBD, 2 x 4 - 40/60 Mk 2, 2 x 2 - 40/60 Mk 1, 9 x 1 - 40/60 Mk III, 5 x 8 - 40/39 Mk VIA, 16 x 2 - 20/70 Mk V, 13 x 1 - 20/70 Mk III, 33 aircraft, type 272, type 277, type 279, type 281B, 6x type 282, type 293, SG radars

mid-1946, Illustrious: catapult was replaced by more powerful, 30% more aviation fuel was carried. Flight deck ends were reconstructed, so its useful area was increased; - 14 x 1 - 20/70; + 1 x 8 - 40/39 Mk VIA, 18 x 1 - 40/60 Mk III, 1x type 282 radar

(3/1950 - 1.1958) Victorious : Hull was lengthened, widened and deepened, machinery and boilers replaced. Two 44m steam catapults, two new faster lifts and angled (8.75°) deck fitted. Hangar height was 5.25m. Electric generating capacity doubled. New artillery fitted.

(fd - 6,366 m², ha - 5,690 m² / 29,869 m³).

8/1963, Victorious: - 2 x 2 - 76/50, 1 x 6 - 40/60, 1x Mk 34, type 262 radars; Angle deck was strengthened, some other improvements were added.

Naval service

Illustrious was badly damaged by direct hits of seven 500kg and 1 250kg German air bombs and one near-miss 10.1.1941. She has received new bomb hits 16.1.1941 during damage repair at Malta. Illustrious has left out of operation for a year. Formidable was damaged by two 500kg bombs 26.5.1941 off Scarpanto and repaired about half a year.

Formidable and Victorious were twice damaged by kamikazes in 1945, but in all cases the ships could continue operational task fulfilment.

Many thanks to Wolfgang Stöhr for additional information on this page.