A METHODOLOGY TO SUPPORT EARLY STAGE OFF-THE-SHELF NAVAL VESSEL ACQUISITIONS

This paper describes a research programme to construct a Model-Based Systems Engineering (MBSE) methodology that supports acquiring organisations in the early stages of Off-the-Shelf (OTS) naval vessel acquisitions. A structured approach to design and requirements definition activities has been incorporated into the methodology to provide an easily implemented, reusable approach that supports defensible acquisition of OTS naval vessels through traceability of decisions. The methodology comprises two main parts. Firstly, a design space is developed from the capability needs using Set-Based Design principles, Model-Based Conceptual Design, and Design Patterns. A key idea is to employ Concept and Requirements Exploration to trim the design space to the region of OTS designs most likely to meet the needs. This region can be used to specify Request for Tender (RFT) requirements. Secondly, the methodology supports trades-off between the OTS design options proposed in the RFT responses using a multi-criteria decision making method. The paper includes an example implementation of the methodology for an indicative Offshore Patrol Vessel capability.

VIRTUAL HULL MONITORING: CONTINUOUS FATIGUE ASSESSMENT WITHOUT ADDITIONAL INSTRUMENTATION

A novel technique to monitor hull stresses using data currently collected on most ships is explored. This technique, referred to herein as virtual hull monitoring, uses global position signals, measured or numerically-modelled wave data, and a database of calculated stress transfer functions. This enables monitoring of short-term stress states and corresponding fatigue damage accumulation for many structural locations, either onboard or at a central location, for an entire fleet. The components, benefits, and limitations of this proposed technique are discussed. Wave buoy and strain gauge measurements from a full-scale naval vessel trial are used in comparisons with hindcast wave data and the calculated stress spectra for one structural location. Close agreement between the wave data sources and corresponding stress spectra warrants further examination of virtual hull monitoring. 

Assessment of the Manoeuvrability Characteristics of a Twin Shaft Naval Vessel Using an Open-Source CFD Code

The purpose of this study is to assess the quality of the manoeuvre prediction of a twin-shaft naval vessel by means of a time-domain simulator based on Computational Fluid Dynamics (CFD) hydrodynamic coefficients. The simulator uses a modular approach in which the hull, rudders, appendices and propellers are based on different mathematical models. The hydrodynamic coefficients of the hull in the bare and appended configurations are computed using virtual captive tests performed with an open-source CFD code: OpenFoam. This paper demonstrates that the application of the CFD hydrodynamic coefficients led to a good estimate of the macroscopic characteristics of the main IMO manoeuvres with respect to the experimental measures. The adopted test case is the DTMB 5415M frigate both with and without appendages. This test case has been investigated in several research studies and international benchmark workshops, such as SIMMAN 2008, SIMMAN 2014 and many CFD workgroups.

Sea Defense Strategy Strengthening Through Improving The Readiness of Indonesian Naval Vessel Crew (Study: The Health Office of 1st Fleet Command)

One of the sea defense strategies in the scope of deterrence is by presenting the Indonesian Navy force in the sea. This demands the readiness of the Indonesian Naval Vessel includes the platform material readiness and its personnel. The Indonesian Naval Vessel unit is generally different from the land unit makes it difficult the crew and need the health manipulation to avoid health problems or diseases that can interfere with their performance. Research errors regarding the implementation of the Indonesian Naval Vessel crew/soldier medical checks at the 1st Fleet Command Health office for readiness in order to support the defense task, the factors that influence and what is the effort supposed to do. The aim of the study was to analyze the implementation of the Indonesian Naval Vessel crew checks at the 1st Fleet Command Health Office what factors influenced and the best strategies implemented to obtain optimal results of the implementation of the Indonesian Naval Vessel crew soldier medical checks. This study uses a qualitative method. The analysis uses the theory of policy implementation from George Edward III. Data were obtained from informants related to the implementation of medical checks for Indonesian Naval Vessel crew in 1st Fleet Command which were then analyzed using qualitative. The results showed that the implementation of medical checks for Indonesian Naval Vessel crew was not optimal. Efforts are being made to coordinate at the planning stage, it is necessary to make a policy that requires Indonesian Naval Vessel crew to carry out medical checks without exception and provide Covid-19 vaccinations. So that soldiers can serve optimally.

Sea Defense Strategy Strengthening Through Improving The Readiness of Indonesian Naval Vessel Crew (Study: The Health Office of 1st Fleet Command) E

One of the sea defense strategies in the scope of deterrence is by presenting the Indonesian Navy force in the sea. This demands the readiness of the Indonesian Naval Vessel includes the platform material readiness and its personnel. The Indonesian Naval Vessel unit is generally different from the land unit makes it difficult the crew and need the health manipulation to avoid health problems or diseases that can interfere with their performance. Research errors regarding the implementation of the Indonesian Naval Vessel crew/soldier medical checks at the 1st Fleet Command Health office for readiness in order to support the defense task, the factors that influence and what is the effort supposed to do. The aim of the study was to analyze the implementation of the Indonesian Naval Vessel crew checks at the 1st Fleet Command Health Office what factors influenced and the best strategies implemented to obtain optimal results of the implementation of the Indonesian Naval Vessel crew soldier medical checks. This study uses a qualitative method. The analysis uses the theory of policy implementation from George Edward III. Data were obtained from informants related to the implementation of medical checks for Indonesian Naval Vessel crew in 1st Fleet Command which were then analyzed using qualitative. The results showed that the implementation of medical checks for Indonesian Naval Vessel crew was not optimal. Efforts are being made to coordinate at the planning stage, it is necessary to make a policy that requires Indonesian Naval Vessel crew to carry out medical checks without exception and provide Covid-19 vaccinations. So that soldiers can serve optimally.

Shape Optimization of an Integrated Mast for RCS Reduction of a Stealth Naval Vessel

In this paper, we analyze the radar cross section (RCS) of an integrated mast and present the optimized mast shape for RCS reduction. The RCS is simulated using commercial electromagnetic (EM) software based on the shooting and bouncing rays (SBR) method and the diffraction fields at the edges are also considered. Threat frequencies, threat regions and cardinal points are first defined considering the operational environments of a naval vessel. We calculate and analyze the RCS of the integrated mast in terms of the threat frequencies, the shapes of the integrated mast and the direction and polarization of the incident waves. The shape of the integrated mast is optimized based on the shaping technique. The optimized mast has low RCS properties in the primary threat sectors except for the exceptional angle regions.

Comparison of Royal Canadian Navy Watchstanding Schedules

ABSTRACT Introduction Life on board a naval vessel is exceptionally demanding. Workdays for naval sailors can quite easily become 18+ hours long when watch schedules, training, and drills/evolutions are taken into account. Rotating watches and short off-watch periods can force sailors into a biphasic sleep pattern that is not sufficiently restful or a rotating pattern that is impossible to adapt to. Materials and Methods Six different watch systems were evaluated over four separate at-sea trials. Engineering and tactical/combat departments have had different watch systems in the past because of constraints related to the specific environment in which they work. Therefore, two of the watch systems were engineering-specific watch evaluations, three of the systems were specific to tactical/combat departments, and one watch system was evaluated with the entire company of the naval vessel. Results Both two-section (1-in-2) watch systems and three-section (1-in-3) watch systems were evaluated, which involve two or three shifts of sailors rotating through a full continuous 24-h day, respectively. Moving beyond three rotations of sailors is impossible on Canadian naval vessels due to bunk space and other limitations. The best watch system that we evaluated with respect to fatigue and quality of life at sea was the 1-in-3 straight 8-h shift system that was tested for the entire ships’ company. The system has a single 8-h daily watch obligation (red watch, 4:00 am-12:00 pm; white watch 12:00 pm-8:00 pm; and blue watch, 8:00 pm-4:00 am). The best 1-in-2 system was the 8-4-4-8 system in which sailors are on-watch for 8 h, off-watch for 4 h, on-watch for 4 h, and then rest for 8 h. Both of these two systems have the advantage of equitably sharing the Window of Circadian Low (from about midnight to about 8:00 am), especially when melatonin concentration in the body is usually at its peak, between 2:00 am and 6:00 am. Conclusions The goal of this work was to comprehensively evaluate both submarine and surface fleet watch systems. We were able to develop alternative watch systems that increased Royal Canadian Navy operational readiness and improved the quality of life of our sailors at sea.