272 



THEORY OF SEAKEEPING 



Conventional Static Calculation l/20 Wove 



Conventional Static Calculation L/20 Wave 



with Smith Correction 



~ U " ■ 



Regulor L/ZO Woves' 



Following Seas 



Legend 

 Peak Bending Moments 

 in Irregulan Waves 

 • Head Seas 

 o Following Seas 



Regulor L/2C 

 Waves 



:.o 



0.5 0.; 



Model Speed, Knots 



1-5 



E.O 



2.5 



Z5 20 15 10 S 5 



Ship Speed, Knots 



15 



20 



25 



00 



90 



eo 



^ ID'S 



Fig. 16 Comparison of peak experimental bending moments in irregular head and following seas with values obtained in regular 



waves, model T2-SE-A1 tanker (from E. V. Lewis, 1954) 



-J 



Peok Sagging Condition 



Condition at Max. Slamming 



Fig. 17 Typical observed wave profiles at speed corresponding to 14V2 knots in irregular head seas, showing maximum bending 

 moments and slamming. From moving picture records of T2-SE-A1 tanker model (from E. V. Lewis, 1954) 



