ABSTRACT
Submarines offer a capability to deploy and retrieve unmanned undersea vehicles (UUV) in littoral and blue water Areas of Operation while avoiding detection. Integration of the submarine and UUV through a launch and recovery mechanism offers unique challenges with respect to host submarine safety, UUV recovery, UUV replenishment and life-cycle costs. The Capstone team elicited launch and recovery system requirements from stakeholders and conceived four (4) advanced alternatives and a baseline alternative considered to meet the requirements. Through functional, cost, risk, modeling and qualitative analysis, this study assessed the value of each alternative to stakeholders. Of the concept alternatives explored, a high tech option featuring a carbon fiber structure, electromechanical pulse launch and recovery device and proximity vice contact battery charging and UUV stowage features provided the best value to the stakeholders for the investment. These results highlighted characteristics, including maintenance considerations, upgradeability, design for reliability and design for universal applications considered paramount for a successful system. Project lessons learned uncovered significant risk due to instability of UUV requirements as well as certification issues which adversely affect a submarine/UUV integration project. Early communications between key stakeholders must effectively address these short-comings.
This paper discusses different approaches to the launch, recovery and stowage of larger Autonomous Underwater Vehicles (AUV) operating from vessels of opportunity in elevated sea states.
The primary consideration for the launch and recovery process is to be able to launch and recover a large AUV using the same aids and procedure for the complete range of operational environmental conditions. Also to undertake the procedure with minimal human intervention during the release and recovery stages of the operation. Dedicated Launch And Recovery Systems (LARS) are extremely effective even in elevated sea conditions, but are sometimes too expensive or do not fit the available deck space of a vessel of opportunity.
This document discusses a cost effective and transportable alternative approach to the launch and recovery procedure using a lightweight vehicle and a simple cradle that protects the vehicle while in transit and is also used for deploying and retrieving the vehicle.
The launch and recovery of large AUVs from vessels and in particular vessels of opportunity presents significant challenges to both manufacturers and operators alike. As AUVs come into ever more increasing use for scientific, military and commercial applications, the need to safely deploy and more importantly retrieve vehicles is paramount. While some AUV operators are able benefit from bespoke systems that are dedicated to the vessel, there is also an increasing need for transportable systems that may be safely operated from vessels of opportunity. When considering the operation of an AUV a number of factors must be discussed. The ability to put a small boat or diver in the water in low sea states mitigates many of the risks associated with recovery operations, however safety considerations, increased sea states or the proximity of pack ice in Polar Regions often prohibit such activities. AUV operators
strive to improve launch and recovery operations to reduce risk, improve safety, reduce environmental impact, and increase operational availability.
An AUV that can be taken in tow with a nose-line deployed upon surfacing, and furthermore withstand the rigors of loading and being hauled out of the water over rollers, can benefit from a simple, easily transportable system such as the Ocean Workers design.
A launch ramp smoothly transitions the AUV from the water to the deck of the boat by stepwise matching of the AUV motions, first to the ramp and then to the ship. A properly implemented ramp may decrease the amount of force that must be carried through the shell and body of the vehicle. Ramp installations can be quite involved if the ship interface is not carefully considered during system design.
A cocoon L&R system can be the most protective for the AUV and least structurally demanding on the AUV. This may lead to a lighter AUV using lighter materials and having less structure-born weight. The cocoon approach can, in some cases, be accomplished with existing ship handling equipment but usually an integrated U-frame design is required.
More