Cameron / Tom / Walter / Michael, Thanks for sharing your thoughts with this newsgroup. Usually stacker-reclaimer systems (mining applications - coal / iron-ore etc.) are laid out with more than adequate space (specifically to avoid bumping into each other). However, in this instance due to space constraints (read cut a few corners to maximise available space), the client wanted us to review the adequacy of anti-collision features of the system (specifically to avoid injury and law-suits).
I will follow-up on suggested leads and get back to the group on my findings. Thanks, Raj