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Saturday 20 August 2016

Preliminary design for the American Pennsylvania-class battleships (BB38&39) dated 1 March 1912

Nevada-class

Preliminary-design Pennsylvania-class


Pennsylvania-class

USS Mew Mexico before the Second World War

Battleships to be built under the Fiscal Year 1913. Based on a design of the preceding Nevada-class battleships and presented to the Navy’s General Board on 2 March 1911. This preliminary was drawn to give an impression if the design dated 14 February 1912 was altered with a lower maximum speed and replacing the turbine machinery by reciprocating machinery and a smaller displacement. The distance between the forward and after pairs of gun turrets was to be made as small as possible.(1)

Dimensions 620 (water line) x 92,5 (outside plating) x 28,5 (mean) feet and a displacement of 30.800 tons. Block coefficient 0,660, longitudinal 0,672, midship section coefficient 0,983. Armament 4x3-14” guns, 22-5” quick firing guns and 4 submerged torpedo tubes. The reciprocating machinery and 16 boilers supplied 27.400 ihp allowing a speed of 20,5 knots and with a speed of 10 knots a range of 8.000 nautical miles. The armament consisted of a main side belt with as extreme width 17’.4 5/8”, depth below waterline 8’6” and a thickness of 13½”, 13½”-8”, barbettes 4½” (light part)-13” (heavy part), turrets 5” (roof)-9” rear)-9/10” (sides)-18” (port), conning tower proper 16” just like the fire control, conning tower tube 6” (light)-16” (heavy), uptake protection 13”, protective deck total 120#(100# S.T.S. over 20# middle), splinter deck total thickness 80#slopes and 60# flats. Percentage waterline protection 0.838. Normal displacement of 30.800 tons: hull complete 13.017 tons, hull fittings 1.260 tons, protection 8.550 tons, steam engineering 2.100 tons, Res. feed 2/3 supply 183 tons, battery 1.550 tons, ammunition &2/3 ordinance stores 1.335 tons, equipment&2/3 equipment stores ad outfit&2/3 stores 1.025 tons, oil fuel 2/3 supply 1.435 tons and 345 tons margin.

Source 
The so-called Spring Styles Book 1 (March 1911-September 1925). Naval History and Heritage Command. Lot S-584-013. Preliminary designs prepared by mostly civilians working at the Bureau of Construction and Repair (succeeded by the Bureau of Ships nowadays the Naval Sea Systems Command) under supervision of naval architects of the Navy Construction Corps. A major part of the drawings was presented to the General Board which advices the Secretary of the Navy. Scheme ‘K”.

Note
1. Pennsylvania-class consisted of the Pennsylvania and Arizona, preceded by the Nevada-class and succeeded by the New Mexico-class. Figures for the USS Pennsylvania.Displacement 28.626 (standard)-32.429 (deep load) tons and as dimensions 182,9-185,3 x 29,72 (waterline x 9,9 (deep load) metres or 600-608 x 97.6 x 29.3 feet. The 4 Curtiss ungeared and Westhinghouse geared steam turbines and 12 Babcock&Wilcox (later 1 Bureau Express and 4 White-Forster boilers) water tube boilers supplied 31.500 shp via 4 screws allowing a speed of 21,38 knots and a range of 6.070 nautical miles with a speed of 12 knots. Crew numbered 915-1.358 men. The armour consisted of a 20,3-34,3cm/8-13.8” thick belt, 3,8-7,6cm/1.5-3” thick decks. 20,3-33cm/8-13” thick bulkheads and the barbettes, gun turrets and conning tower protected by 20,3-33cm/8-13”, 12,7-45,7cm/5-18” and 40m6cm/16”. The armament consisted of 4x3-35,6cm/14” /45 guns, 22012,7cm/5” /51 guns, 4-7,6cm/3” /50 anti aircraft guns and 2-53,3cm/21” torpedo tubes.