Gun crews lived and worked in spaces like this.
Take into consideration that guns like this could weigh about 2 tons apiece,
more for a 32 or 42 pdr gun and what you end up with is an environment that
would give a health and safety official the screaming willies.
Dangerous enough, more so in battle.
Just imagine the damage that could be done if say,
a cannon broke loose in rough seas and yes,
that is where the saying about loose cannons comes from if you didn't know.