Ship survivability

Experience

In order to evaluate the ability of naval vessels to carry out a mission, CETENA has an extensive experience on IR/acoustic signature analysis and vulnerability simulations thanks to years of research, experimental surveys and to the constant interaction with the navy over the years.

Our activities

Since 1998 CETENA has provided IR signature analysis for Italian Navy vessels and has taken part in NATO Task Group on the characterization and measurement of Naval Infrared Target and Background Signatures. CETENA ensured the IR signature control for Fincantieri Naval Vessels starting from the Design phase, through the “as-built” and verification phase carried out with measurement campaigns, in collaboration with the Italian Navy. CETENA uses software tools adopted by the NATO Group, validated during the years by the most important Navies of the world, capable of predicting the infrared signature of naval vessel in their sea background in any type of operative conditions.

The underwater radiated noise from ships has become an important issue, in particular for the potential negative impact that it can have on marine life, above all on mammals. In the past, the control of the underwater radiated noise (acoustic signature) was a precondition only to naval and research vessels; nowadays, it is subject to a careful attention by marine protected area, harbour authorities and shipowners.
CETENA has planned and realised a new system for the measurement of the underwater radiated noise, composed by a string of hydrophones (array) that turns out to be a flexible system and consistent with the regulations requirements and the international procedures. This system comes with a variable geometry in terms of total lenght and space between the hydrophones, according to (as regulations require) the lenght of the ship to be studied.

CETENA combines years of experience in numerical simulation with strong experimental expertise. This set of skills contributes to the validation of the numerical models developed and it allows to realistically evaluate these phenomena (realistic cavitation observation, measurement of pressure induced by the propeller on the hull and of the noise radiated in far-field and the study and validation of the relationship between them). It also allows to verify that the contractual and legal requirements are fulfilled (measures to achieve Additional Class Notation, in collaboration with the Registries of Classifies) and to ensure the identified corrective actions through experiment.

From 1992 CETENA develops in-house software tools for the evaluation of the ships’ vulnerability. The original SAVIUS code, developed on the initiative of the navy and validated with real trials, has been replaced in 2015 by VULNUS, currently in use by Fincantieri and other customers of the national defence industry.

VULNUS is able to recreate the ship structure and its systems and to assess the vulnerability to threats as anti-ship missiles, grenades and light weapons. The code was made to be used from the very first phase of core design for trade-off evaluations among the different configurations on the unit, and so it allows to follow the ship during its life cycle to monitor its performance. VULNUS has recently been given the capacity to assess the non-immediate damage following a fire and/or a flooding of the unit. This capacity is currently undergoing additional improvements together with the capacity of modelling the effect of multiple strokes.