Dan K wrote:
Your last post was intriguing so, I took a look at the Hara Shobo plan book. What several of the CV plans, especially Hiryu, seems to show is that what I've always thought of as the crew stations between, say the forward 12.7cm mounts 1 & 2, and 3 & 4, is packed with ready ammo boxes. Further, at least for Hiryu, there does seem to be a magazine within the ship's hull at the level underneath this area. OTOH, There does not seem to be anything contained within the mount support.
It's expected that AA guns should have ready use munition stowed nearby to facilitate a rapid response and high initial rate of fire when the ship is surprise, as it would be before effective air warning radar. I am still doubtful that ready use munition around open 5"/40 mount is meant to last through not just the initial phase but the entire engagement.
IN any case, the dome shaped smoke proof shields on the 5"/40 mounts behind the funnels doesn't seem to have any openings in the back to allow ready use ammo to be manually delivered from outside. In any case the smoke would make manual munition delivery from outside impossible, thus nullify the function of the smoke proof shield. The shield seem to small to accommodate any significant number of ready use rounds inside. So the dome shaped 5" turrets at least should have some form of internal mechanical ammunition delivery system, which in a rotating turret could only come through the center of the roller path. But inspection of pictures and model of Shokaku shows the support for the dome shaped turrets are essentially identical to those for the open mounts forward and on the other side of the ship. This suggest whatever mechanical ammunition transfer mechanism serves the dome shaped turret also serves the open turrets.
Do you have any illustration of Japanese 5"/40 type 89 mount which indicates the function of the small compartment to the right side of the barrel that has a vertical slot like opening in the back? I am guessing the slot in that compartment is where shells sent up through the hoist emerges to be picked up by the loaders.