Damage Stability of Tankers

A paper was submitted by a group of sponsors led by the United Kingdom to the 83rd Session of the Maritime Safety Committee proposing a high priority new work progamme item devoted to the issue of damage stability on tank vessels.  The co-sponsors believe that oil, chemical and gas tankers are regularly operating in conditions with reduced or zero levels of residual stability and proposed that these vessels should be required to demonstrate compliance with the relevant stability requirements to Port State Control, preferably by use of an on-board computer.  A follow-up paper by one of the co-sponsors proposed that the same should apply to bulk carriers. 

This issue was hotly debated, with many pointing out that no justification had been provided for the allegations in the paper and asking that more information be provided before proceeding with this issue.  In the end the proposal was accepted by a very small margin, and the issue will go forward to the Sub-Committee on Stability, Loadlines and Fishing Vessel Safety, which met in July. The original co-spnors of the paper to MSC submitted a further paper to this sub-committee, reiterating their concerns and suggesting that Guidelines be issued in respect of requirements for vessels to demonstrate their compliance with the damage stability requirements to Port State Control prior to sailing.  The UK position on this has consistently been that the only practical way for vessels to do this is by means of a computer programme conforming to IACS URL 5, preferably of Type 3 (capable of carrying out the full range of damage stability calculations), while others contend that it is possible to do so by means of limiting KG curves. IPTA had concerns about the content of this paper and submitted, jointly with ICS and OCIMF, a paper outlining these concerns. After further lengthy debate, the sub-committee report  noted: