Located between decks on some starships and installations, middle deck utility passages can range from two to five meters in height and one to three meters in width. These passages are used for routing key utility functions throughout the ship, and also serve to allow for engineering crews to have easy access to systems and utilities which require repair. These utility passages have been designed to include hatches and access covers which have been designed with locking mechanisms which require proper clearance to be disengaged, which prevents potential accidents or prohibited utility access.