Personnel safety apparatus is provided on a machine to prevent users from falling while moving between access points on the machine. The apparatus includes a rail having a first end positioned adjacent a first user access point and a second end positioned adjacent a second user access point to define a rail path that spans a vertical elevation. A carrier is movably coupled to the rail and has a first mode, in which the carrier engages a fixed position on the rail, and a second mode, in which the carrier is permitted to move relative to the rail. A tether extends between a harness on the user and the carrier to secure the user to the machine.