Design G3 Final Design February 1921
The final design of the battlecruiser sequence, G3 was a development of the H3 series and the most impressive. A high metracentric height was designed in to allow G3 to remain stable with her spaces outside the citadel riddled with battle damage.
Displacement: 48,400 tons; dimensions 850ft (wl) length, 106ft beam, 32ft 6ins draught. Machinery 160,000shp for 32kts. Calculations showed 32kts just possible but the powerplant had been squeezed in the and the aft lines alerted causing a 7.5% performance penalty, later reduced to 4% from further Haslar tank tests, but 32kts might have been narrowly missed. Fitting a 180,000shp plant was briefly considered, it would have increased length by 25ft and only provided 0.5kt improvement.
Armament: three triple 16in turrets, eight twin 6in turrets, six single 4.7in HA, four multiple pom-pom mounts (10 or 8-barellled though the official plans show four 6-barelled experimental mounts), four 3pdr saluting guns, two submerged 24.5in torpedo tubes (6 torpedoes each, oxygen enrichment equipment would also be fitted). Each weapon system had director fire (two main director control towers, four 6in director control towers, one HA director control tower, one HA rangefinder, four pom-pom directors, two torpedo rangefinders and one conning tower rangefinder). The DNC wanted the torpedo tubes removed but was overruled. Two aircraft could have been carried on B and X turrets but no final decision was made.
Armour: main belt 14in inclined at 18 degrees (reduced from 25 degrees on the initial G3 design); 8-4in deck armour, 4in over machinery spaces (increased from 3in on the initial design), 8in with 9in slopes over the magazines and fwd and middle boiler rooms, 7in over aft 6in magazine and half of after engine room. The changes added 1,125 tons but savings elsewhere reduced the additional weight to 710 tons. The torpedo protection could withstand a 750lb charge, increasing the system to withstand 1,000lb would have increased the size of the ship too much.
The Legend was approved in August 1921 and four ships were ordered on 26 October from Beardmore, John Brown, Fairfield and Swan Hunter but almost immediately halted by a Cabinet order and then in February 1922 cancelled due to the Washington Treaty. It remains speculation if the order was serious or just a bargaining chip for the Washington talks, although it seems the Admiralty were keen to have them and still desired new battlecruisers though Britain was in a financial crisis and it seems unlikely they (or at least all) would have been completed. Names were never finalised and quoted names in several sources are speculative. From several viewpoints in term of armament and armour the G3 surpassed even later designs excepting the Yamato and even the Iowa (in terms of armour at least in this case). While the Japanese and Americans had developed the Amagi, Kii and Lexington to counter the Admirals, the RN had moved on further and the G3s made everything else under consideration at that time look obsolete. Their novel design was probably flawed given blast concerns with X turret given the experience of damage to Nelson and Rodney whenever they fired abaft of their beam with their forward turrets. However, in terms of fire control, turreted secondaries, extensive AA armament and their internal belt and torpedo protection systems they were far superior to any other design then under consideration. Anthony Preston Conway’s makes an interesting statement in comparing the development from Dreadnought to G3 in just over a decade.
Drawing Notes: This drawing is based off the official DNC plans drawn up in February 1921 and signed off by D’Enycourt and were so detailed that all but the minor details are essentially correct. The ship is shown with the armament depicted on the drawings, hence the early model turrets for the 16in Mk I and 6in Mk XXIII that differ from those eventually fitted to the Nelsons. Also note the experimental six-barelled pom-poms as shown on the drawing, basically six singles mounted on a common mounting. There is some debate as to whether ten or eight-barrelled mounts would have been fitted, had they completed then the eight-barrelled would have been fitted in the 1930s as they became available, the ten-barrel is a far more elusive beast and was probably speculative. Since there are barely any parallel sides and most superstructure surfaces are angled I have used a few extra shades to show the complicated shapes, the forward tower being a very complicated structure. I think this is the most accurate portrayal of G3 it is possible to get and I hope you enjoy it.