NAVYPEDIA

Photo

Ajax 1935

Ships

Name	No	Yard No	Builder	Laid down	Launched	Comp	Fate
Achilles (RNZN 10.1941-9/1946)	70, 1948- C70	983	Cammell Laird, Birkenhead	11.6.1931	1.9.1932	6.10.1933	to India 7.1948 (Delhi)
Ajax	22, 1948- C22	682	Vickers-Armstrong, Barrow	7.2.1933	1.3.1934	12.4.1935	sold for BU 11.1949
Leander (RNZN 10.1941-5/1944)	75, 1948- C75		Devonport DYd	8.9.1930	24.9.1931	24.3.1933	sold for BU 12.1949
Neptune	20		Portsmouth DYd	24.9.1931	31.1.1933	23.2.1934	sunk 19.12.1941
Orion	85, 1948- C85		Devonport DYd	26.9.1931	24.11.1932	18.1.1934	sold for BU 7.1949

Technical data

Max speed, kts, kn	32.5
Displacement standard, t	6985 - 7270
Displacement full, t	9000 - 9280 (later 9460 - 9740)
Length, m	159.1 pp 169.0 oa
Breadth, m	17.0 Leander: 16.8
Draught, m	5.79 - 5.99 deep load (later 6.07 - 6.22)
No of shafts	4
Machinery	4 sets Parsons geared steam turbines, 6 Admiralty 3-drum boilers
Power, h. p.	72000
Fuel, t	oil 1680 - 1785
Endurance, nm(kts)	10300(14)
Armour, mm	box protection to magazines: 89 - 25, belt: 76 on 25mm plating, bulkheads: 38, barbettes: 25, turrets: 25, deck: 51 - 25
Armament	4 x 2 - 152/50 BL Mk XXIII, 4 x 1 - 102/45 QF Mk V, 4 x 1 - 47/40 Hotchkiss Mk I, 3 x 4 - 12.7/62, 2 х 4 - 533 TT, 2 (later 1) aircraft (Fairey III, Osprey, Seal), 1 catapult D-I-L Leander: 4 x 2 - 152/50 BL Mk XXIII, 4 x 1 - 102/45 QF Mk V, 4 x 1 - 47/40 Hotchkiss Mk I, 3 x 4 - 12.7/62, 2 х 4 - 533 TT, 2 (later 1) aircraft (Fairey III, Osprey, Seal), 1 catapult E-II-H
Complement	570

Standard scale images

Graphics

Project history

First British cruisers designed under terms of London conference of 1930, according to which Britain had the right to build till 1936 some cruisers of a 'B' category (no more than 10000t displacement , no more than 155mm main guns calibre) with the 91000t common displacement. It was supposed to build 14 6500t ships designed on a basis of Exeter with similar protection but with 8 152mm guns and less powerful machinery. The latter, together with some re-planning of boiler rooms, has allowed to deduce boiler uptakes to single funnel.

As well as on Kent class, basic thrust became not on achievement of a high speed or heavy armament, but on seaworthiness and endurance. Unlike cruisers with 203mm guns they not were so rigidly limited by limitations as a result their displacement significantly (almost on 1000t) exceeded the planned. It has compelled Admiralty to shrink number of ships of class to 8 (taking into account three "improved" ships of Amphion class).

Protection

Armoured belt protected machinery spaces (51mm armour on 25mm plating) and extended to upper deck abreast boiler rooms and to main deck abreast engine rooms. Machinery also was protected by 32mm armoured deck. Magazines were covered by 89mm longitudinal and 76mm transverse bulkheads and 51mm crowns. Steering gear was protected by 32mm deck with 38mm slopes.

Modernizations

1936 - 1938, all but Achilles: - 4 x 1 - 102/45; + 4 x 2 - 102/45 QF Mk XVI

3/1936, Achilles: - 1 catapult D-I-L with Osprey seaplane; + 1 catapult E-II-H with 1 Walrus seaplane

1939, all: - 4 x 1 - 47/40

6/1940, Ajax: - 1 catapult D-I-L with Osprey seaplane; + 1 catapult E-II-H with Walrus seaplane, type 279 radar

2/1941, Orion: + type 286M radar

5/1941, Neptune: + 3 x 1 - 40/39 QF Mk II, 3 x 4 - 12.7/62, type 281, type 284, type 285 radars

5/1941, Ajax: - 1 catapult with seaplane; + 1 x 4 - 40/39 2pdr QF Mk VIII

6/1941, Leander: - 1 catapult with seaplane; + 1 x 4 - 40/39 2pdr QF Mk VIII

8/1941, Orion: - 1 catapult with seaplane

late 1941, Leander: - 3 x 4 - 12.7/62; + 1 x 4 - 40/39 2pdr QF Mk VIII, 5 x 1 - 20/70 Oerlikon Mk II/IV, 1 catapult E-II-H with 1 Walrus seaplane

early 1942, Ajax: + 6 x 1 - 20/70 Oerlikon Mk II/IV

2/1942, Orion: - 3 x 4 - 12.7/62; + 2 x 4 - 40/39 2pdr QF Mk VIII, 7 x 1 - 20/70 Oerlikon Mk II/IV

4/1942, Orion: - type 286M radar; + type 273, type 279, type 284, type 285 radars

1942, Achilles: - 4 x 1 - 102/45, 3 x 4 - 12.7/62; + 7 x 1 - 20/70 Oerlikon Mk II/IV

mid-1942, Leander:+ type 284, type 291 radars

9/1942, Ajax: - 3 x 4 - 12.7/62, type 279 radar; + 1 x 4 - 40/39 2pdr QF Mk VIII, 3 x 1 - 20/70 Oerlikon Mk II/IV, type 272, type 281, type 283, type 284, type 285 radars

10/1942, Orion: + 2 x 1 - 20/70 Oerlikon Mk II/IV

early 1943, Leander: - 1 catapult with seaplane; + 4 x 1 - 20/70 Oerlikon Mk II/IV, type 273 radar

8/1943, Ajax: - 2 x 4 - 40/39, 4 x 1 - 20/70, type 284 radar; + 2 x 4 - 40/56 Bofors Mk 1.2, 4 x 2 - 20/70 Oerlikon Mk II/IV, type 282, Mk 4 radar

10/1943, Orion: - 2 x 4 - 40/39, 4 x 1 - 20/70; + 2 x 4 - 40/56 Bofors Mk 1.2, 4 x 2 - 20/70 Oerlikon Mk II/IV

5/1944, Achilles: - 1 x 2 - 152/50 ("X"), 3 x 1 - 20/70, 1 catapult with seaplane; + 4 x 2 - 102/45 QF Mk XVI, 4 x 4 - 40/39 2pdr QF Mk VIII, 7 x 2 - 20/70 Oerlikon Mk II/IV, type 277, type 281B, 4x type 282, 2x type 285, type 293 radars

1944, Ajax: + 1 x 2 - 20/70 Oerlikon Mk II/IV

4/1945, Achilles: - 2 x 2 - 20/70; + 4 x 1 - 40/56 Bofors Mk III, 1 x 1 - 20/70 Oerlikon Mk II/IV

mid-1945, Orion: + type 283 radar

8/1945, Leander: - 1 x 2 - 152/50 ("X"), 5 x 1 - 20/70; + 2 x 4 - 40/56 Bofors Mk 1.2, 3 x 2 - 20/70 Oerlikon Mk II/IV, 2x type 285 radars

9.1946, Achilles: 3 x 2 - 152/50 Mk XXI, 4 x 2 - 102/45 Mk XIX, 4 x 1 - 40/60 Mk III, 4 x 4 - 40/39 Mk VII, 5 x 2 - 20/70 Mk V, 5 x 1 - 20/70 Mk III, 2 х 4 - 533 TT, type 277, type 281B, 4x type 282, 2x type 285, type 293 radars

1.1946, Ajax: 4 x 2 - 152/50 Mk XXI, 4 x 2 - 102/45 Mk XIX, 2 x 4 - 40/60 Mk 2, 5 x 2 - 20/70 Mk V, 5 x 1 - 20/70 Mk III, 2 х 4 - 533 TT, type 272, type 281, type 282, type 283, type 285, Mk 4 radars

1.1946, Leander: 3 x 2 - 152/50 Mk XXI, 4 x 2 - 102/45 Mk XIX, 2 x 4 - 40/60 Mk 2, 2 x 4 - 40/39 Mk VII, 3 x 2 - 20/70 Mk V, 4 x 1 - 20/70 Mk III, 2 х 4 - 533 TT, type 273, type 284, 2x type 285, type 291 radars

1.1946, Orion: 4 x 2 - 152/50 Mk XXI, 4 x 2 - 102/45 Mk XIX, 2 x 4 - 40/60 Mk 2, 4 x 2 - 20/70 Mk V, 5 x 1 - 20/70 Mk III, 2 х 4 - 533 TT, type 273, type 279, type 283, type 284, type 285 radars

Naval service

Achilles and Ajax were damaged 13.12.1939 in battle with German heavy cruiser Admiral Graf Spee, repair lasted 2 and 6 months respectively. Achilles was damaged by Japanese bomb at Guadalcanal 5.1.1943 and has failed almost on one and half year. Ajax was damaged 1.1.1943 by the 500kg bomb off Cape Bon (Mediterranean sea) and has failed for a year. Leander was damaged by Japanese 610mm torpedo 13.7.1943 in battle at Kolombangara (Solomon Islands) and was under repair till the end of war. Orion was damaged 29.5.1941 by German aircraft off Crete (2 bomb hits) and has failed for 9 months. Neptune was lost after being stricken by three or four Italian mines off Tripoli 19.12.1941.

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