The invention relates to an
expansion joint (10) for connecting regions of a rail-based grid storage
system (50, 50′, 50″; 104, 104′, 104″), the
expansion joint (10) comprising: —a first rail element (12) and a second rail element (11), the rail elements (12, 11) being elongate and configured to slide relative to one another in a longitudinal direction in a
junction area where they overlap, —the
expansion joint (10) having a profiled upper surface that defines one or more tracks (27′, 27″) for supporting container handling vehicles (200, 300, 400), the tracks (27′, 27″) extending from the first rail element (12) through the
junction area to the second rail element (11), wherein in the
junction area, each rail element (11, 12) provides a portion of the or each track (27′, 27″) of the profiled upper surface so that there is a transition extending along the expansion joint (10) from the first rail element (12) to the second rail element (10) for the or each track (27′, 27″). The invention further relates to an automated storage and retrieval
system comprising said expansion joint (10) and a method of connecting regions (50, 50′, 50″; 104, 104′, 104″) of a rail-based grid storage
system and / or delivery rail system using one or more of the expansion joints (10)