Updated 19 May 2009

USS Pensacola CA-24 in July 1945
USS Pensacola was the first 8 inch (20.3 cm) "Treaty" cruiser built by the USA
Note the thick chase of these guns and the "boxy" look of the mountings, both typical of USN 8" (20.3 cm) designs of the 1920s.  Rangefinders on forward turret have been removed.  Putting the twin turret forward rather than the triple turret allowed a narrower bow form, thus making it easier to achieve high speeds.
At left are USS Indianapolis CA-33 and the lighter YF-390
U.S. Naval Historical Center Photograph # 19-N-87792

After mount on USS Indianapolis CA-33 in July 1945
U.S. Naval Historical Center Photograph # 19-N-86916

USS Quincy CA-39 passing through Straits of Magellan in 1939
Note single periscope on the mounts, indicating that the guns were in one sleeve
U.S. Naval Historical Center Photograph # 83592

Bow mounts on USS Portland CA-33 in 1944
Note the Mark 8 FC Radar on top of the Mark 34 Director and the SK "matress" antenna on the foremast.  At the very top of the foremast appears to be an SP radar antenna.
U.S. Naval Historical Center Photograph # NH 82031

USS New Orleans CA-32 in March 1945
Note the different shape of these later turrets, built during the 1930s
U.S. Naval Historical Center Photograph # 19-N-80232

After mounts on USS Lexington CV-2 in January 1927
Note that only the upper mounting has a rangefinder

Weapons intended for USS Louisville CA-28 under construction at the Washington Navy Yard

Triple Mount on USS Salt Lake City CA-25
Blistered paint and extruded liners show heavy use
US Navy Photograph

Cutaway sketches of 8" (20.3 cm) projectiles

26 May 2007 - Benchmark
19 May 2009 - Added picture of Pensacola