ABSTRACT
Strengthening and modification or repair schemes for offshore structures are frequently required in order to sustain additional load carrying capabilities or to compensate for perceived damage that may be induced through service exposure or incident. A wide range of schemes exists so the optimum choice requires consideration of their technical, operational and economic features. Sometimes this choice is relatively straightforward but, on other occasions, the choice is less obvious. Until recently, all choices have been limited to those requiring diver and/or ROV intervention. However, a scheme has now been devised which requires no direct assistance of divers or ROVs. The scheme was proved last year when the world’s first diverless underwater structural repairs were successfully implemented in the North Sea.
This development arose, in part, from a major joint industry project concerned with underwater strengthening, modification and repair (SMR) techniques. The project has been executed by MSL Engineering and has resulted in a design manual which fully describes the advantages of each technique, as well as the limitations and disadvantages, equally important when selecting a technique for a particular application.
This paper details the increased range of SMR techniques now available. Their advantages and disadvantages are discussed for the selection of the optimum solution. Site-specific conditions have considerable influence on the final choice and initial sizing is sometimes necessary before an option can be fully evaluated. These aspects are discussed in the context of SMR applications in water depths up to 1000m.
