1> Central Elevator: the central elevator accesses all decks. It will take d10-3 turns to call the elevator (zero or less means the car is already on that deck), depending on what deck it was on last. Command officers (captain, pilots, engineers, astrogators, and gunnery officers) can halve that time by overriding the elevator with their ID (command officers have priority so the elevator won't stop at other decks while called upon). The elevator will sound an alarm tone when sensing a vaccuum outside, two buttons on opposite sides of the door must be pressed to open the door into a vaccuum (the elevator will depressurize and then open).
2> Parts and tool storage: there are cabinets along each wall for small parts and tools, along with monitoring gauges for each engine.
3> Engine Access: Each engine strut has a two part accessway, with an airlock/decontamination chamber followed by the access tunnel. These accessways slope down (at a 30 degree angle) and away from the hull.
Approximately 50% of the overhaul time will be spent in the engine room/accessways, with the remaining 50% in the Engineering Deck.