The main components of the divertor support structure are an inner and outer ring mounted on a baseplate (fig.1). The outer diameter of the assembly is 6.2m and the inner diameter 4.5m. The divertor structure was manufactured as twenty four sub assemblies which were assembled together once inside the vacuum vessel. JET's CAT (Computer Aided Theodolite) system was used extensively throughout the manufacture and assembly of the structure, and was also used in-vessel to ensure the accurate installation and positioning of the structure with respect to the magnetic centre of the machine. It was decided to evaluate the structure integrity during the Remote Tile Exchange (RTE) [4], when the MKIIA tile carriers were replaced by the MKIIGB carriers, by surveying to allow a size and shape assessment to be made [1]. A survey to metrology standards was required i.e. with submillimetre accuracy. Due to the lack of manned access to the vacuum vessel, the survey would have to be carried out remotely. As difficulty was expected with fitting conventional targets to the structure remotely, a survey system with targetless capability was required. There were two aspects to the survey, one concerned the preparation of the appropriate measuring procedures, while the second was to carry out an engineering analysis of the divertor structure based on the survey results. Consequently the structure was assessed to identify all possible failure scenarios, quantified in terms of deflections or shape changes on the structure. The 'allowable deviations' established here determined how a reasoned assessment of the structure could be made, based on survey results.