Designed from the keel up for naval support, the Navajo class T-ATS rescue and salvage ship pairs the towing muscle of an anchor-handling tug supply (AHTS) vessel with the cargo deck of an offshore supply ship. That combination gives the Navy one flexible hull that can take on many different missions globally.  PCCI investigated the operational capabilities of the Flyaway Deep Ocean Salvage System (FADOSS) deployed aboard a T-ATS salvage vessel. The FADOSS is a modular, motion‑compensated lift system capable of recovering objects of up to 30 tons at depths of up to 20,000 ft and is designed for rapid deployment.

Using OrcaFlex, a high-fidelity simulation of the fully coupled lifting system was developed to define the conditions under which safe recovery operations can be conducted at sea. The analysis encompassed a range of realistic operational scenarios, including a variety of vessel loading conditions, payload configurations —flooded states of the Dry Combat Submersible (DCS) and an F-35C aircraft — and multiple crane positions. Simulated sea environments ranged from moderate to very high seas and across13 wave headings spanning the port side of the vessel. A dedicated time-domain analysis was also performed to assess peak line loads when the Ship Motion Compensator (SMC) reaches the limits of its stroke travel.

The study identified the governing constraints on safe lifting operations across all simulated conditions, established the sea states and wave headings within which each payload can be recovered without exceeding equipment limits, and quantified the peak structural loads generated when the Ship Motion Compensator reaches the boundary of its operating range. Results were delivered as polar contour plots for each payload, crane position, and vessel loading condition, giving operators clear and actionable guidance on safe working boundaries across a full range of sea conditions.