On-board reassessment of sea conditions for marine operations

byChristophe Capitant

(presented by Christophe Maisondieu)

PrISM_MSEM System

The context :

SAR operations at sea

Most of the time in rough sea conditions

Require ability to predict the response of ships and other systems with accuracy and in a reliable way

« Trial and error » : not an option

Quick investigation of many alternatives

PrISM_MSEM System

The current maritime situation :

Factors that produce maritime incidents :

Diversity of older vessels and state-of-the-art ships

Reduced crew

Areas of high density shipping

Increasing levels of traffic and higher transit speeds

Commercial requirements force ‘ short-cuts ’

PrISM_MSEM System

PrISM_MSEM System

Increased risk in marine operations due to :

Severely limited ‘ sea sense ’ when in rough sea conditions and/or hazardous situations such as towing, rescue operations, damage control, etc….

Management of multiple and concurrent navigation issues : (security, ship motion, structural stress, transit speed optimisation, etc…)

Difficulty to provide all the relevant information to the final human deciders in a useful form.

PrISM_MSEM System

The current requirements :

Choice of the best course under meteorological and operational constraints :

Assess the consequences of the various options in extreme situations before taking the decision

Shorten the decision process

Increase navigation accuracy

Limit ship fatigue and risk of failure

Avoid serious damage and possible pollution

PrISM_MSEM System

Our option :

Enhance local sea-state forecast.

Use EO enhanced forecast

to predict the ship or system response to further enhance the local forecast by comparing

with observed ship response. to simulate the ship behaviour even after a change

in the course.

PrISM_MSEM System

The mean : PrISM

a system developed for helicopter deck-landing operations and adapted to other marine operations.

Main features :

Implementation of cutting-edge maritime environmental data and ship motion models

Use of Artificial Intelligence : System adapts automatically to the real time measured sea-state using genetic algorithms Emulation of the human decision-making process by use of fuzzy logic

Implementation of highly efficient optimisation algorithms (multi-parameters: roll, bending moment, towline tension, ...)

PrISM_MSEM System

PrISM main results :

Operational simulations show :

Significant reduction of the inaccuracies in the local sea-state models

Reduction of the global ‘energy density spectrum’ of the response of the ship when selecting the solution recommended by the system, i.e. :

reduced ship motion reduced structural stress

Optimisation of the navigation course in terms of safety

PrISM_MSEM System

The Ship and Marine Environment Model Interface

PrISM_MSEM System

The Self-Adaptation of the Sea-State Interface

PrISM_MSEM System

The Motion and Structure Management Interface

PrISM_MSEM System

The Route Optimisation Management Interface

PrISM_MSEM System

The Navigation Management Interface

PrISM_MSEM System

Projects :CAMMEO

Co-Ordinated Approach to Markets for Marine Earth Observations

Would assimilation of Earth Observations measurements in forecast enhance the ability of the PrISM_MSEM system to accurately evaluate the local Sea-state ?

PrISM_MSEM System

Forecast Forecast +EO

Best Local Sea-State

PrISM_MSEM

Projects :CAMMEO

Assessment and validation tests

on-board R/V THALASSANovember 2004Bay of Biscaye

PrISM_MSEM System

Proposal :SARASSEN

SAR ASSistant for Enhancement of Navigation

Develop, install and test a full system on-board SAR vessels :

PrISM_MSEM System

FORECAST

Sea-State Input Data

HYDRODYNAMICS SOLVER

(Tow-line and assisted ship dynamics)

PrISM_MSEM

Local Sea-State

Best course/speed options