Alternate County Class Heavy Cruisers.
With a 10,000 ton limit set by the Washington Treaty for cruisers, innovative ideas were required for a new cruiser class for the Commonwealth Navies. The Hawkins class with their long range, high freeboard and decent speed, were valuable as long range patrol cruisers, it was the Hawkins' unhandy armament of single, hand worked 7.5" that were the classes largest problem. The hull was fine, the armament was rubbish. Putting the same 7.5" guns into triple turrets and mounting two forward and one aft gave a much better balanced main armament. Single 4" AA guns were eventually replaced with twin 4" as those weapons became available. The tertiary/AA weaponry centered on the new multi-gun 2pd pom pom with two octuple and two quadruple mounts being fitted. More AA weapons were added and/or replaced as they were added to the armoury listings (0.5"mg, 20mm, 40mm). Two sets of triple 21" torpedo tubes were fitted amidships. Keeping the 7.5" instead of going to a new 8" gun specified by the Treaty kept one less set of ammunition out of the listings and the current line manufacturing the 7.5" guns could continue producing the same guns. The elevation of the guns went from 30 degrees (21,200 yards) on the Hawkins to 45 degrees (30,500 yards) on the Countys. To go to the 8"instead would also have returned to the virtually unarmoured Countys which I was trying to avoid.
The change in main armament layout also required a revision of the magazines and machinery layouts. Steam turbines of 70,000shp driving through 4 shafts gave a sea speed of 31 knots, while speeds of 32-33 knots were achieved on trials (by ships in the class) with 108% of standard output. Range was 6,500 miles at 14 knots.
The armour of the original class of 3" belt and 1-to-1 1/2" deck armour was adequate but was increased to provide more protection to the vitals. The belt armour increased to 4" while the deck armour over the magazines and machinery was increased from 1 1/2" to 2". The rest of the deck armour remained at 1". The turrets were armoured with a 4" faceplate, 2.5" roof, sides and rear. This up armouring came at a cost with nearly 700 tons being added to the displacement.
While the length of the hull remained the same the breadth had had to be increased to mount the new triple turrets. This had also provided the space for the uprated machinery. The extra width also allowed a cross-deck catapult to be fitted, deemed a necessary item for long range patrol cruisers.
The Hawkins class displacements were 9,500 tons designed, 9,750 tons standard, 12,100 tons full Load. The County class had a designed displacement of 10,000 tons but additions and improvements increased this in service to 10,800 tons standard and 13,500 tons full load.
![[ img ]](https://dl.dropboxusercontent.com/u/67325036/HMAS_Canberra_%28CA-1928%29.PNG)
Some issues have been raised by members and I have altered the drawing as shown below in comparison to the original
![[ img ]](https://dl.dropboxusercontent.com/u/67325036/HMAS_Canberra_%28CA-1928-v2%29.PNG)
Added another Alternate County, HMS Roxburgh of 1927.
![[ img ]](https://dl.dropboxusercontent.com/s/uj4iulfap7nodoa/HMS_Roxburgh_%28CA-1927-v1%29.PNG)