Evacuation Analysis on Passenger Ships: Simplified and Advanced Method
This is not a drill carried out on board: it is an analysis that must be conducted at the design stage, even before the ship is built, to demonstrate that evacuation is possible within the required time.
Operational Explanation
MSC.1/Circ.1533 ("Revised Guidelines on Evacuation Analysis for New and Existing Passenger Ships") makes evacuation analysis mandatory at the design stage for every passenger ship carrying more than 36 passengers, with keel laid from 1° January 2020, no longer only for Ro-Ro passenger ships as previously.
The guidelines offer two methods: a simplified method, based on formulas and standard assumptions about the flow of people, suitable for less complex ship configurations; and an advanced method, based on dynamic simulation of people's movement, necessary when the assumptions of the simplified method no longer hold (for example in the presence of complex architectural layouts, multi-deck atriums, non-linear evacuation routes).
Regulatory Reference
MSC.1/Circ.1533 (superseding the previous MSC.1/Circ.1238): mandatory evacuation analysis at the design stage for passenger ships with more than 36 passengers, keel laid from 1° January 2020, with a choice between simplified and advanced method depending on the complexity of the configuration.
Scope of Application
Passenger ships carrying more than 36 passengers, with keel laid from 1° January 2020; the obligation applies both to Ro-Ro passenger ships and to other types of passenger ships.
Procedure / How to Complete It
- At the design stage, determine whether the ship's configuration allows use of the simplified method or requires the advanced simulation method.
- Conduct the evacuation analysis according to the chosen method, verifying compliance with the required evacuation times for the applicable scenarios (day/night).
- Integrate the analysis results into the actual layout of escape routes, stairways and assembly points.
- Keep the evacuation analysis documentation on board or accessible for reference during audits and surveys.
- In the event of significant structural modifications to an existing ship that alter the evacuation routes, reassess the original analysis.
Practical Example
Example: the designer of a cruise ship with a multi-deck central atrium and non-linear evacuation routes uses the advanced dynamic simulation method, since the simplified assumptions about the flow of people would not be representative of such a complex architectural configuration.
Real Cases
Common Mistakes Mistake Library
| Mistake | Consequence | How to avoid it |
|---|---|---|
| Using the simplified method for complex ship configurations in which its underlying assumptions no longer hold | Evacuation analysis not representative of actual behaviour in an emergency | Assess the complexity of the configuration before choosing the method, opting for the advanced method when necessary |
| Subsequent structural modifications to the ship that alter evacuation routes without reassessing the original analysis | Evacuation analysis no longer consistent with the ship's actual configuration | Reassess the evacuation analysis whenever a structural modification alters the routes or escape ways |
PSC Observations
Operational Tips
- Do not underestimate the ship's architectural complexity when choosing the method: a multi-deck atrium is typically a signal that the advanced method is needed.
- Keep the documentation of the original evacuation analysis on board: it is a useful reference in case of future modifications or audits.
- Coordinate any refit that alters evacuation routes with a reassessment of the analysis, not just with the structural approval of the refit itself.
Checklist
- Evacuation analysis method (simplified or advanced) chosen based on the complexity of the configuration
- Required evacuation times verified for the applicable scenarios (day/night)
- Analysis results integrated into the actual layout of escape routes, stairways and assembly points
- Analysis documentation available on board or accessible for reference
- Reassessment conducted in the event of structural modifications altering evacuation routes