Fuel Outflow

This module calculates the mean oil outflow parameter in accordance with "MARPOL, ANNEX 1 Regulation 12A - Oil fuel tank protection", paragraph 11 plus "MARPOL Regulation 23 - Accidental oil flow performance", and compares this to the standard required.

The calculations performed by the Oil Outflow function only deals with the probabilistic approach in the regulations.

Note:
MARPOL ANNEX 1 Regulation 12A only applies to ships with an aggregate oil fuel capacity greater than 600 m3.

Both reg. 12A and reg 23 are very similar and are based on the probability of accidental outflow occurring. This assessed by calculating a mean outflow performance parameter, Om, which in turn is derived from the formula:

Om = (0.4Oms + 0.6Omb)/C

Where:

Oms = mean outflow for side damage

Omb = mean outflow for bottom damage

C = total oil volume for fuel or cargo tanks respectively.

Om must be lower than the limiting value specified in the rules.

Tables for the probabilities of side and bottom damage, based on the tank's size, position and minimum distance from the shell, are given in the regulations. These are the same for both fuel and cargo oil tanks. However, the determination of Oms and Omb differ depending on whether tanks carry fuel or cargo.