Lightweight Beaching Ramp for Ships

PROJECTED CMMC LEVEL REQUIREMENT
Level 2 (Self)
TECHNOLOGY AREAS
None
MODERNIZATION PRIORITIES
Advanced Materials
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Sustainment & Logistics
KEYWORDS
Medium Landing Ship (LSM); lightweight Ramp; Lightweight ferry ramps; Advanced Materials; Corrosion resistance; Roll-On/Roll-Off (RO-RO) ramps
OBJECTIVE
Develop a durable, lightweight, corrosion-resistant beach ramp for newly constructed Medium Landing Ships (LSMs).
DESCRIPTION
The Medium Landing Ship (LSM) is a new construction beachable vessel intended to perform ship-to-shore amphibious movement of cargo, equipment, and troops. To accomplish the loading and unloading of equipment, a large vehicle ramp is needed for Roll-On/Roll-Off (RO-RO) capability. Large RO-RO ramps are used on multiple ship classes and are commonly made of heavy steel, susceptible to corrosion and maintenance issues. On beaching vessels, these ramps are constantly subjected to saltwater immersion and are expected to traverse a long distance to provide a safe transfer of vehicles to the shore. Without a properly functioning ramp, the primary mission of these beaching vessels is compromised. There is currently no commercial technology that can meet this need.
The Navy seeks a reliable, low maintenance, corrosion resistant ramp system for beaching vessels. The legacy ramps are mostly made of steel and are often submerged in seawater while rolling stock compromises paint protection causing corrosion. Due to complex geometric challenges of beaching a large vessel, complex articulating beaching ramps tend to be very long and heavy (typically about 75' and 110 tons). These length and weight challenges of deployment systems tend to be unreliable and often have mission degrading failures. The solution should be at least 13 ft in width and 75 ft in length and support a maximum vehicle load of 70 tons (tire contact load of 32,100 lbs. over 24 x 25.5 patch area). The ramp should be articulated from a single hinge point using hydraulics on the ship. However, the solution can be divided into as many subsections as necessary such as employing the use of multiple folds to accommodate the length and weight requirements. The time it takes to deploy the ramp, however, shall not exceed 30 minutes.
The technology should utilize maintainable systems for deployment and retraction. The developed solution should reduce maintenance requirements while maximizing reliability of the deployment/retraction system. The durability of corrosion resistant material should last the life cycle of the ship (30 years). The solution should take extreme environmental conditions such as wind, humidity, and sea spray into consideration as such conditions can decrease the life cycle of a technology. The solution should have a nonskid surface that is able to withstand the demands of high traffic during loading and offloading of heavy equipment and vehicles.
PHASE I
Develop a concept for a lightweight beaching ramp for ships that meets the requirements in the Description. Demonstrate the feasibility of the concept in meeting Navy needs by material testing and analytical modeling. If the Phase I Option is exercised, include the initial layout and capabilities to build the prototype in a Phase II plan.
PHASE II
Develop and deliver a scaled prototype beaching ramp that meets the requirements of the Description. The prototype will be installed on an appropriate test platform in a simulated environment for durability and load testing. These evaluation results will be used to refine the prototype into a design that will meet the LSM specifications. Prepare a Phase III development plan and cost analysis to transition the technology into Navy use.
PHASE III DUAL USE APPLICATIONS
Support the Navy in transitioning the lightweight beaching ramp for Navy use on the LSM program. Refine the design of the lightweight beaching ramp based on Phase II testing results and prepare for Low-Rate Initial Production (LRIP).
The durable lightweight beaching ramp will have private sector commercial potential for all types of RO-RO ships of this scale operating in the near-shore or on-shore environment, which currently use expensive to procure and maintain steel designs. Commercial applications include ferries, RO-RO ships, transport aircraft, the oil and mineral industry, and cold climate research and exploration.
REFERENCES
Jalkevik, Aron and Toresson, Karl. "Fatigue Assessment of Stern Ramps." Department of Shipping and Marine Technology Division of Marine Design, Research Group Marine Structures Chalmers University of Technology, Master's Thesis X-13/289, G teborg, Sweden 2013. https://publications.lib.chalmers.se/records/fulltext/194841/194841.pdf
Roper, Adam. "A Comprehensive Guide to RoRo Ramps and Linkspans." Adam Roper, 8 July 2024. https://adamdroper.com/roro-roll-on-roll-off-linkspan
Tao, S.; Zhu, L.; Liang, Q. and Zhang, Q. "Reliability Analysis of Ro-Ro Vessel Movable Vehicle Ramps Under Vehicle Moving Load." Proceedings of the ASME 2024 43rd International Conference on Ocean, Offshore and Arctic Engineering, Volume 2: Structures, Safety, and Reliability. Singapore, Singapore, June 9-14, 2024. V002T02A026. https://doi.org/10.1115/OMAE2024-124733