Updated 04 February 2013

USS Idaho (BB-42) about 1920
U.S. Naval Historical Center Photograph # NH 53203

USS Idaho (BB-42) being regunned in late 1920s by Crane Ship No. 1 (ex-USS Kearsarge)
Note the plated over secondary casemates
U.S. Naval Historical Center Photograph # NH 43457

USS Idaho (BB-42) being regunned in late 1920s by Crane Ship No. 1 (ex-USS Kearsarge)
Note that the gun house needed to be dismantled in order to change out the guns
U.S. Naval Historical Center Photograph # NH 43458

Cutaway sketch of 14"/50 (35.6 cm) Three-gun turret
Although official documents note 300 projectiles per mounting, there appear to be 374 projectiles in this sketch including 55 ready rounds in the gunhouse
Sketch from "Naval Ordnance 1939" an Annapolis Textbook

World War I 14" (35.6 cm) Railway Gun in April 1920
National Photo Company Collection
Library of Congress Photograph ID LC-DIG-npcc-28937

World War I 14" (35.6 cm) Navy Railway Gun, this one is now at the Washington Navy Yard, Washington DC
Photograph copyrighted by Charley Seavey

US Army Model 1920 Railroad Gun in 1924 with Naval 14" (35.6 cm) gun.  Note the carriage outriggers and the projectiles in the foreground.
U.S. Army Ordnance Department Photograph No. 19489

12 January 2009 - New datapage
04 February 2013 - Added cross-sectional sketch