🔍 Key Concepts

• High tensile steel (HTS) properties compared with mild steel • Where classification societies are most strict about fracture, buckling, and damage tolerance in the hull girder • Relative importance of keel, sheer, and margin strakes in overall longitudinal strength and protection

💭 Think About

• Which strakes form the outermost, most critical longitudinal strength members of the hull shell? • If HTS is stronger but often less ductile, in which locations would surveyors and rules be most conservative about allowing it? • Think about grounding and side damage: which strakes must absorb damage with the greatest toughness rather than just high strength?

✅ Before You Answer

• Be clear on what each term means: sheer strake, keel strake, margin strake • Consider which areas rules often require special material toughness or thickness, not just higher strength • Ask whether rules are more likely to say “only here,” “never there,” or “may be used generally if rule conditions are met” for HTS in shell plating