The Ammo Bay was introduced in the very first version 0.1 and was the first storage part made. It was the only cannon ammo storage available until Cosmoteer 0.12 introduced the Ammo Storage 7-8 months later. It can hold 39 cannon shells. Since the introduction of explosions in Cosmoteer 0.11.4 its use has become hazardous.
Like other storage it requires no further attention.