A lift system mountable in a nacelle of a wind turbine has a boom having a proximal end mountable in the nacelle and a distal end extending over a hub of a rotor of the wind turbine when the lift system is mounted in the nacelle. The lift system has a frame structure for mounting the proximal end of the boom in the nacelle, a winch mounted to the boom, a fastener situated below the boom and operatively connected to the winch by at least one cable, and a trolley movably mounted to the boom to permit translation of the trolley longitudinally along the boom thereby permitting longitudinal movement of the fastener with respect to the boom.