USS Idaho (BB-42) was one of the 12 "Standard Type" battleships constructed during WW1 and just afterwards. The Standards began with
USS Nevada BB-36 and completed with
USS West Virginia BB-48.
The
Idaho was one of three
New Mexico class battleships, basically a slight improvement over the preceding
USS Pennsylvania class, with 12 (4x3) 14"/50 caliber cannons being more powerful than the previous 14"/45 caliber. However following the attack at Pearl Harbor, there was a rush to increase air defenses and modernize the ships.
USS Idaho received a massive increase of ten 40mm Bofors quad mounts in 1942, replacing the ineffective quad 1.1" cannons. Uniquely, in 1944, the
Idaho received 10 single mount 5"/38 caliber dual purpose mounts - the same as on the Fletcher class destroyers rather than the dual 5"/38 caliber mounts on all other US battleships and cruisers.
https://en.wikipedia.org/wiki/USS_Idaho_(BB-42)
Idaho (BB-42) (foreground) and
Texas (BB-35). Steaming at the rear of the battle line, during Battle Fleet practice off the California coast, circa 1930.
Idaho's four triple 14"/50 gun turrets are trained on the starboard beam.
Idaho (BB-42) in 1935.
Close up views of port side showing the 5"/38 caliber single enclosed mounts added to the
Idaho (BB-42) at Puget Sound Naval Shipyard in late 1944.
Port side view of the
Idaho (BB-42) as refitted and on post-refit trials on 2 January 1945.
Idaho (BB-42) steaming through the Panama Canal, en route to the U.S. east coast for Navy Day celebrations in October 1945.
