A grid framework structure

A grid framework structure for supporting a load handling device operative to move one or more containers, the grid framework structure comprising:

• a plurality of upright members arranged to form a plurality of vertical locations for one or more containers to be guided by an upright member in a vertical direction;
• wherein the plurality of upright members are interconnected to define nodes at their top ends by a plurality of grid members arranged in a grid pattern, the grid members including a first set of grid members extending in a first direction and a second set of grid members extending in a second direction, the second set of grid members running transversely to the first set of grid members in a substantially horizontal plane to form a grid structure containing a plurality of grid cells;
• the grid structure including a track system positioned on the plurality of grid members, the track system including a plurality of tracks arranged in the grid pattern;
• the grid structure including a first region and a second region;
• wherein the grid framework structure includes a bridging joint assembly arranged as one or more connections between the first region of the grid structure and the second region of the grid structure, said bridging joint assembly including at least one mechanical fuse that is arranged to break under an applied load greater than or equal to a predetermined load, said predetermined load being lower than a load for breaking interconnections between the plurality of upright members and the plurality of grid members of the grid structure so as to allow the first region of the grid structure to separate from the second region of the grid structure when the applied load exceeds the predetermined load.