This shot shows Rory Edwards tapping one of the holes for the crown stays. It should be noted that over half of the tap is already inside the boiler. It needs to be so long as it has to create what will be a continuous thread in both the outer wrapper and also the top or crown of the inner firebox. (Samples of the new crown stays are shown in photo 78).
Credit: Dick Bellchambers, 15 March 2006