A maintenance system for a wind turbine apparatus, the wind turbine apparatus including a vertical turbine tower, a wind turbine mounted on the turbine tower and a nacelle, an access platform, and a cargo elevator cable assembly having a cable and a device raising and lowering the cable, said maintenance system comprising: a cargo elevator for receiving a tool and/or parts storage box for delivery to or reception from the nacelle, said cargo elevator comprising: a cable attachment structure for securing said cargo elevator to the cable; characterized in that the wind turbine apparatus comprises a vertical track system extending between the access platform and the nacelle, wherein said cargo elevator further comprises: a track engagement-and-traveling assembly for engaging the vertical track system to move said cargo elevator along the vertical track system; a tool and/or parts storage box-holding shelf for holding the tool and/or parts storage box on the cargo elevator; and the nacelle has a nacelle entrance angularly separated from the vertical track system, the wind turbine apparatus further has a circumferential track system for transporting a tool and/or parts storage box from said cargo elevator on the vertical track system to a location proximal the nacelle entrance, and a cargo carrier ring assembly circumferentially mounted at least partly around the turbine tower, the cargo carrier ring assembly having cargo carrier connectors extending exteriorly from the cargo carrier ring assembly and movable between a location proximal the vertical track system and a location proximal the nacelle entrance, said maintenance system further including: a cargo carrier for reception from or delivery to said cargo elevator, the tool and/or parts storage box, at a location proximal the vertical rails, said cargo carrier comprising: a tool and/or parts storage box-holding frame; a latching mechanism for releasably latching the tool and/or parts storage box on said tool and/or parts storage box-holding frame; and a cargo carrier ring-locking structure for cooperating with the cargo carrier connector to lock said cargo carrier to the cargo carrier ring. a cargo elevator for receiving a tool and/or parts storage box for delivery to or reception from the nacelle, said cargo elevator comprising: a cable attachment structure for securing said cargo elevator to the cable; characterized in that the wind turbine apparatus comprises a vertical track system extending between the access platform and the nacelle, wherein said cargo elevator further comprises: a track engagement-and-traveling assembly for engaging the vertical track system to move said cargo elevator along the vertical track system; a tool and/or parts storage box-holding shelf for holding the tool and/or parts storage box on the cargo elevator; and a track engagement-and-traveling assembly for engaging the vertical track system to move said cargo elevator along the vertical track system; a tool and/or parts storage box-holding shelf for holding the tool and/or parts storage box on the cargo elevator; and the nacelle has a nacelle entrance angularly separated from the vertical track system, the wind turbine apparatus further has a circumferential track system for transporting a tool and/or parts storage box from said cargo elevator on the vertical track system to a location proximal the nacelle entrance, and a cargo carrier ring assembly circumferentially mounted at least partly around the turbine tower, the cargo carrier ring assembly having cargo carrier connectors extending exteriorly from the cargo carrier ring assembly and movable between a location proximal the vertical track system and a location proximal the nacelle entrance, said maintenance system further including: a cargo carrier for reception from or delivery to said cargo elevator, the tool and/or parts storage box, at a location proximal the vertical rails, said cargo carrier comprising: a tool and/or parts storage box-holding frame; a latching mechanism for releasably latching the tool and/or parts storage box on said tool and/or parts storage box-holding frame; and a cargo carrier ring-locking structure for cooperating with the cargo carrier connector to lock said cargo carrier to the cargo carrier ring. a cargo carrier for reception from or delivery to said cargo elevator, the tool and/or parts storage box, at a location proximal the vertical rails, said cargo carrier comprising: a tool and/or parts storage box-holding frame; a latching mechanism for releasably latching the tool and/or parts storage box on said tool and/or parts storage box-holding frame; and a cargo carrier ring-locking structure for cooperating with the cargo carrier connector to lock said cargo carrier to the cargo carrier ring. a tool and/or parts storage box-holding frame; a latching mechanism for releasably latching the tool and/or parts storage box on said tool and/or parts storage box-holding frame; and a cargo carrier ring-locking structure for cooperating with the cargo carrier connector to lock said cargo carrier to the cargo carrier ring.