High-Capacity Alongside Sea Base Sustainment (HiCASS) SBIR/STTR
The HiCASS product line is also investigating several technologies via the SBIR/STTR program.
N03-100 Technologies to Support RO/RO Cargo Transfer in Sea State 5
The objective is to develop new materials and/or manufacturing techniques to provide high strength, light weight, high flexibility structures for transfer of Roll-On/Roll-Off (RO/RO) cargo between two freely floating vessels in the stream in sea states up to sea state 5. The current state of the art for RO/RO transfer in the stream is sea state 3, and many ramps are not certified for that. New concepts of Expeditionary Warfare dictate greater standoff distance from the beach to conduct in-stream operations. As the distance from the beach increases the probability of encountering sea states of 3 or less is reduced. The ability to operate in sea state 5 is required to have a sufficient operational window at the standoff distances. Ramps will be required to bridge between two independently floating bodies to allow vehicles to drive from the delivery vessel to the receiving vessel. The two vessels will have pitch, heave and roll characteristics that will likely be different from each other creating relative motions between the two ends of the ramp. The motions will also impart accelerations to the vehicle driving across the ramp. The ramp would have to be flexible enough in torsion to allow the relative motions between the ends of the ramp while also providing adequate strength and stiffness along the axis of the ramp. The receiving vessel will likely be much smaller than the delivery ship, and a heavy ramp would swamp the receiving vessel in a seaway. Ramps that are lightweight relative to their rated load and that are flexible are also useful pierside as they reduce weight impacts on the vessel. Similar technologies could be used for hoistable decks for car carriers.
SBIR N031-0597 Advanced Composite RO/RO Ramps with Active Controls for Sea State 5 - Foster-Miller, Inc.
Current Navy Roll-on/Roll-off ramps and RRDF platforms for in the stream cargo transfer are limited to operation in sea state 3. New concepts of Expeditionary Warfare require greater standoff distance, resulting in operational exposure to conditions up to sea state 5. Foster-Miller proposes a system study that incorporates our large composite bridging expertise with the RO/RO experience of MacGregor, Inc, the Class Standard supplier of ramps for the Navy. The composite material will be 25 percent lighter, more corrosion resistant, and have greater overall strength and flexibility. The Foster-Miller system will include active controls to isolate the ramps and cargo from the extreme wave motions and forces. Floating body relative motions will be developed using state of the art software. The key focal points of the program will be sea state 5 capability, weight savings, and operational efficiency. Foster-Miller will team with MacGregor Inc, and also Professor Paul D. Sclavounos, Director of the MIT Laboratory for Ship and Platform flows, a leading expert in relative motion studies. The program will develop concepts that will be risk reduced in Phase II with follow-on model basin testing and commercialization through MacGregor.
The limits of existing passive ramp transfer systems have been developed for sea state 3 conditions, and suggest that an active approach is necessary to move to the next level of performance, in which the ramp position is automatically adjusted to compensate for strong sea motions. An integrated ramp system was conceptualized that is based on active control for maintaining critical positioning during RORO operations. That system is shown in accompanying figure. The ramp system was designed for 300 ft ship to ship spacing with full operational capability in sea state 5. Innovative high-torque, high-speed motors under development at Foster-Miller through separate ONR funding, enables an all-electric system for control. Sensors constantly monitor the relative position of the ramp to the vessels, allowing for safe, rapid positioning with no loss of throughput. Total ramp system weight is estimated at 200 Short Ton with peak power requirements of 20 MW to enable active position control.
SBIR N031-1575 Modular Composite Roll On/Roll Off Ship Ramp Structures - DDL Omni Engineering, LLC, Inc.
In this Phase I effort DDL OMNI Engineering demonstrated the feasibility of an innovative composite Roll-On/Roll-Off (RO/RO) ramp concept that enables in-stream transfer of cargo from logistic supply ships to floating causeway RO/RO discharge facility (RRDF) platforms during sea state 5 (SS5) seaway conditions. The concept is based on the development of modular composite RO/RO ship ramp structures that incorporate several unique design features enabling the structure to respond in an acceptable manner to dynamic seaway conditions. These design features are: (1) a lightweight, high-strength and modular composite structure based upon application of low cost "Cell Core" technology; (2) smart composite manufacturing processes to permit low cost and reliable manufacture of the composite structural elements; and (3) the integration of flexible structural joints with elastomeric bearings and/or flexures (leaf springs) into the ramp support structure to provide supplemental motion compensation and controlled flexibility. Work will include both static and dynamic analyses of the proposed concept to estimate the relative motions between ramp ends and accelerations imparted to vehicles traversing the ramp structure. The concept will be refined during Phase I by using design optimization procedures to conduct performance and cost trade-offs.
The overall objective of this Small Business Innovative Research (SBIR) Phase I research project was to demonstrate the feasibility of an innovative composite Roll-On/Roll-Off (RO/RO) ramp concept that enables in-stream transfer of cargo from logistic supply ships to floating causeway RO/RO discharge facility (RRDF) platforms during sea state 5 (SS5) seaway conditions. The concept is based on the development of hybrid steel-composite RO/RO ship ramp structures that incorporate several unique design features including: (1) a lightweight, high-strength and modular composite ramp deck based upon application of low-cost "Cell Core" technology; (2) smart composite manufacturing processes to permit low cost and reliable manufacture of the composite structural elements; and (3) the integration of flexible structural joints with elastomeric bushings and semi-active magnetorheological (MR) fluid damping devices into ramp support structures.
Integration of flexible structural joints and semi-active structural damping devices into the composite ramp support structures will provide controllable flexibility and supplemental motion mitigation between the RO/RO ramp and RRDF platforms to enable significant reductions in ramp stress levels associated with induced torsion, bending and acceleration loads. The work performed in preparation of the Phase I SBIR Final Report included material selection trade studies, development of notional concept designs for key modular composite ramp components, structural finite element analyses to predict structural performance under static and dynamic load conditions, and development of preliminary prototype designs. The final report is presents an introduction and background information related to Littoral Combat and Power Projection-Expeditionary Logistics future naval capabilities (FNC), Seabasing, and conducting Roll-on/Roll-off (RO/RO) operations in sea state 5 conditions. It also presents a detailed description of the analytical efforts, conclusions, recommendations for conducting the proposed OPTION task and for planned Phase II efforts and the commercialization strategy for transitioning the composite materials and structural damping technologies to both military and private-sector markets.
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