Alternative Design


The "Alternative design and arrangements" (AD&A) activities that CETENA has been carrying out for several years to support the design of passenger ships are, in general, aimed at studying alternative design configurations, accepted by flag administrations and naval classification bodies as long as they guarantee levels of safety equivalent to or higher than those prescribed by the regulations. CETENA has carried out several AD&A studies, thanks to an interdisciplinary team made up of experts in safety, naval installations and Fire engineering. The company has supported Fincantieri and Vard in the design of most of the modern classes of passenger ships and carried out consultancy activities for the most important ship classification bodies at international level.

Our activities

The methodology followed to demonstrate the equivalence of the alternative design is reported in the IMO-MSC / Circ.1212 and describes the procedural and technical process to develop the necessary engineering checks to support the demonstration.

The main areas in which CETENA works in the field of AD are:

  • Capacity of the means of evacuation
  • Layout of the fire zones (Main Vertical Zone)
  • Fire doors and unconventional shutters
  • Passive systems for fire containment


The application of risk analysis techniques assisted by the application of specialized simulation tools (evacuation analysis, passenger flows, fire CFDs, plant engineering studies) allow the development of complex safety analyses according to regulations (IMO, national , classification bodies) and the specific requirements of shipowners, allowing to grasp any "weak links" in the project in advance and also allowing to improve the effectiveness of the devices analysed by maximizing the payload capacity in compliance with the safety standards required by the regulations.