"The basic concept of the present work is the definition of an effective repair method for large steel structures with defects. Two basic steel structural types will be dealt with in this work, namely marine structures and steel civil engineering structures. The objective of this project is to demonstrate that composite patch repairs can be environmentally stable and therefore, that they can be used as permanent repair measures. This objective will mainly be achieved by: 1) Studying and demonstrating through theoretical analyses, numerical simulations and experimental testing that the use of composite patch repairs leads to the reinforcement of a steel structural member. 2) Determining, evaluating and quantifying the efficiency of composite patch reinforcements in the marine/bridge environment, in both the short and long term. 3) Developing a generalized procedure for the design and application of composite patch reinforcements in steel marine and civil engineering infrastructure applications. 4) Evaluating existing or developing new, practically applicable and sensor based monitoring techniques of the final through-life structural integrity of the patch. 5) Demonstrating the effectiveness of the developed design tools and procedures through full-scale tests. 6) Developing an internationally recognised training programme for personnel. The objectives defined above are in full line with the requirements of FP7-SST-2008-RTD-1 call for proposals. The proposed composite patch repair technology is an innovative and highly competitive product that caters to the needs of both marine vessels and civil engineering infrastructures. It reduces quite significantly the maintenance costs of many large steel structures, and in the case of metallic bridges it prolongs their design life. The proposed technology creates a new market and it gives the partners the capability of providing high technology and high added value services worldwide."