1. For aerial tram carriers a spheroidal cover providing a passenger supporting seat structure and adapted for use with a suspension yoke having a lower U-shaped carrier supporting portion, comprising in combination: two pivot structures, each having laterally inner fastening disks and laterally outer journal elements structurally carried by each lower end of the suspension yoke; a frame depending from and communicating between the fastening disks of the opposed pivot structures: a hemispheroidal back cover structurally communicating for support at least with the frame, with an axis of revolution substantially through the pivot structures, rearwardly enclosing a seat structure to support passengers; and a shell-like, hemispheroidal forward cover with inside radius slightly greater than the outside radius of the back over and with annular fastening disks along a diameter substantially coincident with an axis of revolution, the fastening disks being journaled respectively upon the outer journal elements of the opposed pivot structures to mount the forward cover for pivotable opening motion over the rearward cover.

7. In a compound, relatively movable aerial tram carrier cover, supported by a U-shaped depending yoke, the combination comprising: a hemispheroidal rear cover carried by the depending yoke along a substantially horizontal axis of revolution; passenger carrying means associated with the rear cover and carried substantially within the enclosed volume thereof; paired opposed pivot structures carried by the end parts of the depending yoke; and a forward hemispheroidal cover having internal radius slightly larger than the external radius of the rear cover, journaled along an axis of revolution on the opposed pivot structures for pivotable opening motion over the rear cover.