Abstract: A track for a grid framework structure configured to guide a load handling device operative to move one or more containers, the rid framework structure including a plurality of grid members converging or intersecting at nodes in a grid pattern to form a grid structure 40 including a plurality of grid cells. The track comprising a plurality of track sections mountable to the grid structure to form a track surface upon which the load handling devices may move on the grid structure, wherein each track section of the plurality of track sections is formed as a unitary body so as to provide a track surface extending in transverse directions.

Abstract: A system for guiding the movement of one or more load handling devices in operation includes: a) a first set of parallel tracks and a second set of parallel tracks, the first and second sets of parallel tracks sharing a common track, each track of the first and second set of parallel tracks providing a track surface; and b) a first load handling device and a second load handling device, each having a wheel assembly engaging with the track surface and with the track surface of the common track; wherein each track of the first and second sets of parallel tracks include only two guide surfaces extending from the track surface for guiding the first and second load handing devices along their respective first and second sets of parallel tracks.

Abstract: A storage system having crash barriers is described. The crash barriers are mounted on separate structures, the structures being mounted adjacent the storage system. The separate structures include tracks such that robotic load handling devices operating on the storage system may over run without causing damage to the main part of the storage system.

Abstract: A storage system having crash barriers is described. The crash barriers are mounted on separate structures, the structures being mounted adjacent the storage system. The separate structures include tracks such that robotic load handling devices operating on the storage system may over run without causing damage to the main part of the storage system.