Bonded crack retarders are a novel technology for improving the damage tolerance of structures. They are of particular interest in aerospace applications, where they offer the potential for enhancing the damage tolerance of structures that do not contain naturalcrack-stoppers, whilst not incurring a weight penalty. We have previously looked at the effect of the reatrders on the stresses around fixing points such as cold expanded holes, and boltted holes. We now want to investigate and quantify the resiudal stresses generated because of the retarder on a simulated manhole structural element which contains an artificial crack. This is required because the carefull control of the resiudal stresses in critical locations of the aerospace structures will enhance the safety of aircraft.