A rail unit includes an upper plate segment extending in a width direction, a lower plate segment extending in the width direction and at a position in a downward direction from the upper plate segment, and an intermediate plate segment extending in a vertical direction and joining an edge of the upper plate segment in a first width direction and an edge of the lower plate segment in a first width direction. A power feeder is located in a space defined by the upper plate segment, the intermediate plate segment, and the lower plate segment in the rail unit. The upper plate segment includes a traveling surface facing in an upward direction. The lower plate segment includes a lower flat portion extending in a traveling path direction and the width direction, and a groove protruding in the downward direction from the lower flat portion and extending continuously in the traveling path direction.

A rail unit includes an upper plate segment extending in a width direction, a lower plate segment extending in the width direction and at a position in a downward direction from the upper plate segment, and an intermediate plate segment extending in a vertical direction and joining an edge of the upper plate segment in a first width direction and an edge of the lower plate segment in a first width direction. A power feeder is located in a space defined by the upper plate segment, the intermediate plate segment, and the lower plate segment in the rail unit. The upper plate segment includes a traveling surface facing in an upward direction. The lower plate segment includes a lower flat portion extending in a traveling path direction and the width direction, and a groove protruding in the downward direction from the lower flat portion and extending continuously in the traveling path direction.

A shiplift transfer system for moving a ship between a shiplift platform and a shipyard is disclosed. The system includes transition rails coupled with the shipyard that are pivotable about trunnion pins between a position that bridges a gap between the shipyard and the shiplift platform and a position that is clear of the gap and of the shiplift platform. The pins are positioned such that the load is not transferred to the pins. Load on the transition rails is reacted at curved surfaces of the transition rails that are engaged with curved surfaces on the yard. The transition rails are accessible for maintenance and replacement via removable plates. The rails include beveling to accommodate misalignment between the yard and platform.

A shiplift transfer system for moving a ship between a shiplift platform and a shipyard is disclosed. The system includes transition rails coupled with the shipyard that are pivotable about trunnion pins between a position that bridges a gap between the shipyard and the shiplift platform and a position that is clear of the gap and of the shiplift platform. The pins are positioned such that the load is not transferred to the pins. Load on the transition rails is reacted at curved surfaces of the transition rails that are engaged with curved surfaces on the yard. The transition rails are accessible for maintenance and replacement via removable plates. The rails include beveling to accommodate misalignment between the yard and platform.

An example robotic device includes: a circumferential carriage configured to drive the robotic device along a rail configured to be mounted to a curved surface, the circumferential carriage comprising: (i) a frame base, (ii) a frame mounted to the frame base, (iii) one or more wheels coupled to the frame base and configured to engage with the rail, (iv) a worm gear arrangement, and (v) a main drive gear coupled to the worm gear arrangement and configured to engage with a rack disposed on the rail; and a transversal carriage comprising: (i) a cross slide slidably mounted to the frame, (ii) a transversal rack coupled to the cross slide, (iii) a cross slide motor mounted to the circumferential carriage, and (iv) a cross slide drive gear coupled to the cross slide motor and having gear teeth engaging with respective teeth of the transversal rack.

An example robotic device includes: a circumferential carriage configured to drive the robotic device along a rail configured to be mounted to a curved surface, the circumferential carriage comprising: (i) a frame base, (ii) a frame mounted to the frame base, (iii) one or more wheels coupled to the frame base and configured to engage with the rail, (iv) a worm gear arrangement, and (v) a main drive gear coupled to the worm gear arrangement and configured to engage with a rack disposed on the rail; and a transversal carriage comprising: (i) a cross slide slidably mounted to the frame, (ii) a transversal rack coupled to the cross slide, (iii) a cross slide motor mounted to the circumferential carriage, and (iv) a cross slide drive gear coupled to the cross slide motor and having gear teeth engaging with respective teeth of the transversal rack.

A support member may be connectable in a removable and adjustable manner to a track assembly. The support member may include an electrical connector, a contact, and a biasing member. The electrical connector may be adjustable to a first position and a second position. The contact may be connected to the electrical connector and configured to engage a conductor of said track assembly. The contact may be engageable with said conductor when the electrical connector is in the first position. The contact may not be engageable with said conductor when the electrical connector is in the second position. The biasing member may be configured to bias the contact into engagement with said conductor when the electrical connector is in the first position.

A support member may be connectable in a removable and adjustable manner to a track assembly. The support member may include an electrical connector, a contact, and a biasing member. The electrical connector may be adjustable to a first position and a second position. The contact may be connected to the electrical connector and configured to engage a conductor of said track assembly. The contact may be engageable with said conductor when the electrical connector is in the first position. The contact may not be engageable with said conductor when the electrical connector is in the second position. The biasing member may be configured to bias the contact into engagement with said conductor when the electrical connector is in the first position.

A method and apparatus are provided for sorting or retrieving items to/from a plurality of destinations areas. The items are loaded onto one of a plurality of independently controlled delivery vehicles. The delivery vehicles follow a path to/from the destination areas, which are positioned along the path. Once at the appropriate destination area, an item is transferred between the delivery vehicle and the destination area.

A method and apparatus are provided for sorting or retrieving items to/from a plurality of destinations areas. The items are loaded onto one of a plurality of independently controlled delivery vehicles. The delivery vehicles follow a path to/from the destination areas, which are positioned along the path. Once at the appropriate destination area, an item is transferred between the delivery vehicle and the destination area.