Safety system for an automated storage and picking system and method of operation thereof

A method of safely stopping a plurality of load handling devices operating on a storage and picking system, the storage and picking system having a first set of parallel rails or tracks and a second set of parallel rails or tracks extending transverse to the first set in a substantially horizontal plane to form a grid pattern having a plurality of grid spaces;

• a plurality of storage containers arranged in stacks, located beneath the rails and at least one load handling device disposed on the grid, arranged to move on rolling means laterally above the stacks on the rails, the method comprising:
• transmitting a signal via a transmitter of the storage system;
• receiving at a load handling device receiver portion, the signal from the transmitter, the receiver portion having switch means for interrupting power to the rolling means of the load handling device via an activation means which stops transmission of the signal from the transmitter on activation by external means;
• and
• activating the activation means by the external means, said activation interrupting the signal, the interruption in the signal causing power to the rolling means of the load handling devices to be cut, thereby stopping the load handling device on the storage system.