Marine Research

Art Anderson Associates has participated in multiple phases of a Small Business Innovation Research (SBIR) program that investigates an approach to joining together sealift vessels in a "train" to improve performance. During the course of the project, numerous analyses were conducted to evaluate the resistance of multiple hulls connected in tandem. These analyses concluded that improvements in performance for a given class of vessels can be realized by connecting them together as a train, particularly if flow disturbances between the hulls are minimized by using a fairing.

The Navy's primary interest in the project is to improve its high-speed sealift capability. Large sealift ships are expensive to build, and can only be constructed at a limited number of US shipyards. The SeaTrain concept enables smaller vessels to fulfill the missions intended for these large ships, enabling significant cost savings because the smaller size allows more commercially-competitive construction at second-tier shipyards. The train concept also enables individual vessels to disconnect and operate independently, providing improved survivability and flexibility in deployment of assets and maintaining the austere port accessibility that is unavailable to larger vessels.

During the Phase I and Phase I Option periods of the research program, Art Anderson Associates analyzed the effects of a SeaTrain-like assembly of LCU-1600 craft, reviewed the connector systems developed during the Mobile Offshore Base (MOB) Program and studied the available post-tensioning systems that could be applied to the sealift ship SeaTrain concept. The Phase II effort, which is currently underway, is intended to empirically verify the potential benefits and challenges of the concept. Objectives in this pahse include verifying the SeaTrain's hydrodynamic properties, developing a hull connection system, conducting a cost-benefit analysis and assessing the potential hydrodynamic efficiency gains of a hull air cavity system.

The Improved Navy Lighterage System (INLS) concept was conceived for the purpose of moving cargo rapidly from a large sealift ship to shore. The Roll-On, Roll-Off Discharge Facility (RRDF) utilizes several INLS modules to provide a stable platform for an LCAC-type craft to land upon. The RRDF, moored alongside a Maritime Force Prepositioning ship, is intended to serve as an interface on which the transfer of cargo from the ship to LCAC shore connectors can rapidly take place. Several full-scale exercises have proven various aspects of this capability. The use of the RRDF will provide tremendous improvements in cargo throughput and safety over the traditional methods requiring entry to an amphibious ship docking well.

The RRDF itself consists of a network of 15 modular barges, with a connector system restraining the network together. Initial seakeeping simulations using the MORA (MOored Response Analysis) suite of multi-body motions analysis, suggests that the design loads in several of the RRDF's side connectors will be exceeded during Sea State 4 in open water operations, even with no cargo aboard. This model test program will first establish the validity of these predictions, then determine if the presence of a large ship hull in close proximity to the RRDF can reduce the magnitude of the wave energy and loads experienced in the RRDF's connectors to acceptable levels.

Model Test goals are to determine if the connector loading values and vessel motions as predicted by MORA are accurate, and validate it as a predictive tool for future work; to determine the effect of the presence of a Sea Lift ship on the Sea State conditions and if the RRDF can be protected in its lee; to determine the allowable envelope of LCAC operations based on RRDF motions in a seaway and to determine of the RRDF can sustain operations in Sea State 4, based on predicted vessel motion and connector loading.

Because of Art Anderson Associates' investigation of innovative technologies, the Navy Sealift Support Program Office, (i.e., the INLS Acquisition Program Management Office) elected to co-sponsor our Phase II and III Small Business Innovation Research (SBIR) contracts, so that we could produce a prototype Improved Navy Lighterage System (INLS) composite module. We put together an Integrated Product Team (IPT) consisting of composite manufacturers, Navy operators, the Navy sponsor, and ourselves as the designer. We often use an IPT approach to ensure that our designs are as producible as they are functional. The 40-ft. long x 24-ft. wide x 8-ft. high prototype was completed and tested at sea by the Navy, who determined that composite materials were a viable competitor to steel design for this system.

The military's Seabasing vision (as described in the Office of the Under Secretary of Defense For Acquisition, Technology and Logistics August 2003 report) requires the Maritime Pre-positioning Fleet of the Future (MPFF) to eventually be located as far as 200 miles offshore, while demanding increased throughput and sea state requirements that are beyond the capabilities of the current INLS. Art Anderson Associates is currently designing the next version of the high-speed, transport module called the High Speed Lighterage Assault Connector (HSLAC), that will provide a platform from which the naval services will be able to operate with tactical superiority.

Detail Design for Marinette Marine

Art Anderson Associates provided detailed design support for the construction of the Improved Navy Lighterage System (INLS) at Marinette Marine Corporation in Marinette, Wisconsin. Prior to this construction award, Art Anderson Associates was heavily involved in the research and development efforts for designing the new INLS prototypes to assist the Navy in evaluating the Lighterage program and its solicitation requirements.

Marinette Marine contracted Art Anderson Associates to provide naval architecture and marine engineering services in support of the design and construction of 29 powered and non-powered modules (floating barges). Altogether, there are six different module types in the system. These modules can be assembled into floating platforms, such as a Floating Causeway, Roll-on/Roll-off ship Discharge Facility or a Ferry, to transport heavy materials such as tanks, trucks, and cargo between ship and shore. As part of this detail design we provided engineering, life cycle management analysis and design for the following:

• Intact and Damage Stability Calculations
• Piping system requirements for tank stowages and preliminary layout of tank(s)
• Lighting, navigational and electrical requirements for system mast(s) and preliminary layout
  
• Drawings for overflows, air escapes, sounding tubes, and spill containment requirements for tanks containing flammable liquids, oily waste, and ballast water
• Fendering requirements inclusive of materials, location and arrangement
• Floor plates and grating