Seakeeptng Constderattons tn a Total Destgn Methodology 
laid a very good foundation and framework for a sophisticated ship 
design methodology, which we badly need, and I thought this might be 
a second instalment in that direction. 
The second reason for my disappointment is because I had 
made repeated attempts to incorporate seakeeping considerations into 
early design decisions, as this paper repeatedly points out by referr- 
ing to reference 5 and while I feel that in reference 5 Professor 
Mandel and myself have described the principles of sucha step, we 
found that it did not influence those early decisions, 
The third reason is that because of the latter experience I 
thought that maybe this paper would show how seakeeping considera - 
tions can influence early gross design decisions. Unfortunately, the 
paper does not achieve this objective. In fact, in the conclusions 
chapter it is even stated: ''The results also suggest that when opti- 
mization does not involve large changes in the principal characteris- 
tics of the different alternatives considered, as in the case of ship 
with constant payload, then seakeeping considerations should not be 
included in the optimization scheme because they are not expected to 
influence the final decision". 
But after all, the normal ship design problem is posed in such 
a way as: ''Transport or carry a certain payload (say with some future 
growth and convertibility for a warship) with a certain maximum speed 
and endurance optimized against some criterion''. Therefore to say 
what the author has stated in the conclusions part of the paper, which 
I quoted earlier, seems to me to cut out the majority of design situa- 
tions. Thus accounting for seakeeping indices, such as acceleration 
in certains locations along the ship, slamming, wetness and added 
powering in waves versus not accounting for them in the normal ship 
design case will not have a significant effect on the gross ship dimen- 
sions, 
Iam obviously not referring to a whole host of ship hull cha- 
racteristics suchas LCB-LCF locations, sheer and freeboard, the 
detailed design of the hull form itself and the selection of various sta- 
bilization systems. What Iam referring to, is this : given the mathe- 
matical model and superimposed optimization technique, reference 5, 
the existence of a subroutine for seakeeping indices considerations 
would not result in, say, a 10-20 percent change in gross ships cha- 
racteristics of a conventional monohull design. 
There is a big difference between being able to predict the per- 
formance of a vessel, which is important, versus changing the signi- 
ficant gross ship characteristics as a result of considering or not con- 
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