A lock for securing upper and lower superimposed shipping containers in place, characterized in said lock comprising: - a vertical housing ( b) having a top portion and a bottom portion, the top portion having a shape fittable in a dedicated opening in a corner casting of an upper container, and the bottom portion having a shape fittable in a dedicated opening in a corner casting of a lower container; - said housing comprising a first and a second housing part; and - said first housing part having a side opening at a lower end of the bottom portion; - said top portion of the housing having a neck and there above a head comprising a retaining flange arranged to provide a retaining function when the top portion is fitted into said dedicated opening in the corner casting of an upper container - at least a hook member pivotally mounted within the housing and having a hook end that can be moved out and moved back through the side opening for coupling the lock to and for uncoupling the lock from a corner casting; characterized by - a spring arranged to push each hook member towards a moved-out position of said hook end; - a shaft mounted in the housing and operatively connected to said at least one hook member to either lock the hook member in the moved-out position of said hook end or permit the hook member to move between the moved-out position and the moved-back position of said hook end; - a motor for moving the shaft; and - a locking bar fixed to the shaft and upon movement of the shaft by the motor being movable between a locking position, where the locking bar engages a locking surface of the hook member and locks the hook member in said moved-out position and a free position, where the locking bar is out of engagement with the hook member. - a vertical housing ( b) having a top portion and a bottom portion, the top portion having a shape fittable in a dedicated opening in a corner casting of an upper container, and the bottom portion having a shape fittable in a dedicated opening in a corner casting of a lower container; - said housing comprising a first and a second housing part; and - said first housing part having a side opening at a lower end of the bottom portion; - said top portion of the housing having a neck and there above a head comprising a retaining flange arranged to provide a retaining function when the top portion is fitted into said dedicated opening in the corner casting of an upper container - said housing comprising a first and a second housing part; and - said first housing part having a side opening at a lower end of the bottom portion; - said top portion of the housing having a neck and there above a head comprising a retaining flange arranged to provide a retaining function when the top portion is fitted into said dedicated opening in the corner casting of an upper container - at least a hook member pivotally mounted within the housing and having a hook end that can be moved out and moved back through the side opening for coupling the lock to and for uncoupling the lock from a corner casting; characterized by - a spring arranged to push each hook member towards a moved-out position of said hook end; - a shaft mounted in the housing and operatively connected to said at least one hook member to either lock the hook member in the moved-out position of said hook end or permit the hook member to move between the moved-out position and the moved-back position of said hook end; - a motor for moving the shaft; and - a locking bar fixed to the shaft and upon movement of the shaft by the motor being movable between a locking position, where the locking bar engages a locking surface of the hook member and locks the hook member in said moved-out position and a free position, where the locking bar is out of engagement with the hook member.