This report is based on more than ten years of research into fatigue crack growth in offshore structures, which has made a positive contribution to structural safety and improved service life. It begins with an overview of experimental work into the variable amplitude corrosion fatigue of T, Y and K joints fabricated from Grade SOD Steel, and the influence of biological fouling on fatigue crack growth. Next, it details the work that was required to incorporate the findings of these tests into a commercial software package to predict fatigue crack growth. The later part of the report is given over to research on high-strength steels, for example X85, subjected to cathodic protection.Content:Front Matter Summary Introduction Table of Contents1. Experimental Work2. Fatigue Crack Growth Software3. High-Strength Steels 4. Conclusions Programme Sponsors