The ITER-like wall project has been launched to design, manufacture and test all the necessary components in view of their installation in a dedicated shutdown 2008–09. One of the R&D activities in the frame of the project is the development of a concept of an inertially cooled bulk W component for the JET divertor. Two options were studied as the concepts, (i) W/CFC brazing design which consists of W blocks on a carbon fibre composite (CFC) tile; (ii) W lamellae design, which is a mechanical assembly of several stacks of W blades. Both concepts were realized as test tiles and tested under high heat flux loading. The lamellae test tile showed a high performance fulfilling the requirements. Finally, the lamellae concept was chosen to be the primary solution and comprehensive numerical analyses were performed for the further optimization of the concept.