5 Calculation of vehicle pollution
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Statutory Documents - IMO Publications and Documents - Circulars - Maritime Safety Committee - MSC/Circular.729 – Design Guidelines and Operational Recommendations for Ventilation Systems in Ro-Ro Cargo Spaces – (Adopted on 4 July 1996) - Part 1 - Design Guidelines and Operational Recommendations for Ventilation Systems in Ro-Ro Cargo Spaces - Appendix 1 - Ventilation of ro-ro cargo spaces - Requirements and basic calculations - 5 Calculation of vehicle pollution

5 Calculation of vehicle pollution

 For calculation of pollution quantity it is important to know the type of engine in the vehicles (diesel, petrol), size, operation cycle (activity on board) and the number of vehicles in operation simultaneously. This varies according to the size and type of the ship and to the design of the forwarding routes and if there are hoists or other arrangements on board which delay the traffic (queuing, idling). The calculation of pollution quantity must, therefore, be based on this and on expected cargo handling operations and the way in which these are organized. Information on the anticipated vehicle mix and operational requirements should be obtained by the designer.

When estimating the pollution generation the ro-ro cargo spaces should be regarded as separate volumes. Places where a particularly high generation of exhaust gas could be expected and areas with limited airflow, must be taken into consideration.

The maximum number of vehicles that may be operated simultaneously should be determined from the amount of pollution generated by the vehicle(s) being operated, when considering the adequacy of the ventilation system.

CO, NO2 and HC in vehicle exhausts are given in paragraph 7 for different modes of operation.

When designing a ventilation system for the dilution and removal of exhaust gases generated by vehicles, it should be noted that CO will be the most significant exhaust gas where petrol engines predominate. Whereas NOx will be most where diesel engines predominate. However, exposures should be kept well below the NOx and CO exposure limits to protect against exhaust gas components for which occupational exposure limits are unavailable.

Parent topic: Appendix 1 - Ventilation of ro-ro cargo spaces - Requirements and basic calculations
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