This paper gives insight into detail design of the MPU Heavy Lifter. The innovative structure is developed for offshore heavy lifting operations like removing or installing platforms. Its hull is composed of highly reinforced and prestressed lightweight concrete forming slabs and walls with thicknesses between 0.3m and 0.9 m. Information is provided on the design procedure, on the basis of design and on the design of B- and D-regions. Structural analysis is based on finite element analysis using shell elements. For design and verification of concrete sections the results are post-processed with specially developed software. For D-regions, truss and stress-field modelling supported by specialised finite element analysis is applied. The applicability of these design methods is verified with a series of small and large scale tests.