The forward 6"/47 Mark 16DP guns aboard the cruiser Worcester.
The Mark 16DP saw the earlier Mark 16 (Cleveland & Brooklyn classes) guns be mated to a new turret and greatly enhanced shell handling equipment.
This allowed the Mark 16DP to retain its powerful anti-ship performance, while granting it autoloading capability and any angle loading. The mounts also featured powerful motors, granting fast traverse and elevation rates.
This made the Mark 16DP one of the first truly successful 6" dual-purpose guns to see service.
However, the weapon was not without drawback.
It was extremely heavy. It was also let down by a complicated dual feed loading system that hampered rate of fire and was unreliable.
Most importantly, it arrived at the twilight of naval anti-air gunnery as jet aircraft were becoming more common.
One of the greatest ships you never heard of. Shinshū Maru was a amphibious assault ship developed by the Japanese before WW2.
To call her innovative would be an understatement as the ship was a collection of advanced features.
The most advanced of which was a large, floodable well deck. This allowed her to rapidly deploy her landing craft during amphibious operations. On the subject of landing craft, she could carry about fifty in addition to four gunboats.
Her massive superstructure was originally intended to function as a hangar, allowing her to handle her own floatplanes to better coordinate landing operations. However she lost her catapults prior to completion and never carried her aircraft.