Deep ocean mining of manganese nodules presents one of the major challenges in technology in areas pertaining to complex design of machinery for long duration operations at about five thousand metres depth on soft ocean floor. Design synthesis for such systems has to be done keeping in view device interactions, cascading effects of probable failures in hyperbaric subsea conditions apart from main functional requirements. In the present study, conventional design synthesis approaches have been enhanced with design fusion methodologies developed like structured mutual fusion, function sharing approaches for reinforcement, buoyancy and protection, mutual balancing of dynamic forces and reactions of devices. Bionic design methods with analogies to nature can be used effectively in design fusion for manganese nodule collection systems. Case studies of failure and its cascading effects experienced in deep seas have been studied and factors to be taken care in design synthesis mentioned. The paper describes in detail the methodologies developed and design synthesis approaches that can be used for designing deep ocean manganese nodule collector systems. Copyright ©2007 by ASME.