Air pipe closing devices

Under certain conditions, The Netherlands accept that air pipe openings on dry cargo ships are not considered as a opening in the probabilistic damage stability calculation. The information below only applies to ships where this principle is applied. 

Existing ships

For ships delivered before the 1st of June 2016, automatic air pipe closing devices can be accepted when the strengthened maintenance regime is followed until the first SOLAS renewal survey after the 1st of June 2016. After this renewal survey, the requirements of the equivalent arrangement as communicated by the IMO in circular letter 3573 is mandatory. 

New ships

For ships for which the first SOLAS safety certificate is issued after the 1st of June 2016, the equivalent arrangement of circular letter 3537 is also mandatory.

Whether the air pipe openings are considered as opening in the damage stability calculation or not can be checked in the damaged stability booklet or damage stability computer input file. In case of doubts further guidance can be obtained with your classification society.