The eight-barreled Mk. VII 40-mm Pom-Pom anti-aircraft guns (2 pound 1.6″ Pom Pom AA gun Mk. VIII) of the Australian Shropshire heavy cruiser (HMAS Shropshire) in the Pacific theater of operations during World War II.
Source of information about the 40-mm Pom-pom anti-aircraft guns photo: www.flickr.com