ILLC 1966 - Bow height

Dear All,

I am new member of this forum. I would like to ask you about some interpretation of ILLC 1966. The matter concerns the idea of increasing the existing draft of the vessel. There is a problem in meeting the criteria of minimum bow height comes from ILLC 1966. In accordance with Regulation 39:
“The bow height defined as the vertical distance at the forward perpendicular between the waterline corresponding to the assigned summer freeboard and the designed trim and the top of the exposed deck at side”
How this definition can be interpreted? Is it possible to assign aft trim as a design trim for this vessel? After slight modification of all loading cases ship will operate only with aft trim condition?
To meet the minimum bow height criterion after increasing of draught we estimate that 0.3m aft trim as a design trim for this vessel allows for the above mentioned conversion practically without any hull modification, increasing the measurement of the bow height.
Our question is if it is acceptable from ILLC point of view.

Thank You

 

This is a question for the vessels national classifing authority. If you re-calculated the vessels entire stability booklet with the aft trim and showed that in all loading and damage cases you brought the vessel up to modern (CLL 66/88 and SOLAS) requirements, then I see no real problem with arguing that she could be classed that way.

However, my basic assumption for most well designed ships of that age (circa 1970?...anyway prior to the '88 protocol) would be that increasing her draft and trimming her aft would bring the stern margin line underwater in the aft damaged condition which would negate any argument for increasing her draft unless there was a significant change to watertight structure aft.

 

Dear Jehardiman
Thank you for your answer. It is consistent with our thoughts, however, I tried to find legal grounds to do it. Do you know any document showing the following interpretation?
Before sending the official request to administration I would like to prove that our interpretation follow the ILLC rules. In accordance with discussion with classification societies (usually they make decisions on behalf of the administration) they suggest that mentioned in Reg 39 "designed trim" refers to vessels with a "rake of keel". I do not agree with that but I have to find arguments to convince them. That they have no opportunity to challenge such a solution.
For your information after checking the stability criteria should not be a problem to fulfill all of them after the assumed increasing draft and aft trim.
Thank You