Abstract: A surveillance system having two or more monitoring devices moving on a single track. The monitoring devices are suitably video cameras but may also include audio monitoring. Power for the monitoring devices, control signals and signals from the monitoring devices are all transmitted on the track. Power is suitably DC and other signals are suitably RF. The system incorporates collision avoidance means to prevent collision between adjacent moving cameras. The collision avoidance means includes hand-over software so that a person can seamlessly scan a region with camera control being passed to adjacent cameras to avoid collision.