Page 367 - statbility for masters and mates

Strength curves for ships 355
Wave Bending Moment (WBM)
Wave Bending Moment WBM bEBEL2:5 10 3 t m
WBM Hogging 9:795 30 2002:5 10 3 t m 166228tm
WBM Sagging 11:02 30 2002:5 10 3 t m 187017tm
Total Bending Moment (TBM)
TBM Hogging WBM hogging SWBM hogging
166 228 17 350 183578tm
TBM Sagging WBM Sagging SWBM hogging 187 017 17 350
169667tm
Answer (a) with crest amidships, the Total Bending Moment, TBM is 183 578 tonnes metres.
Answer (b) with trough amidships, the Total Bending Moment, TBM is 169 667 tonnes metres.
The greatest danger for a ship to break her back is when the wave crest is at amidships, or when the wave trough is at amidships with the crests at the stem and at the bow.
In the previous example the greatest BM occurs with the crest amidships. Consequently, this ship would fracture across the Upper Deck if the tensile stress due to hogging condition became too high.