Flange gaps are measured while pulling or pushing rusty bolts through bolt holes. This minimizes the likelihood of jamming the bolts or studs inside the holes. The ThinJackGAP is a real-time gap-data system for all flange-separation methods. The system displays the gap between the two parts of the bolted flange during their separation. If this is not measured, there is a risk that the flange is tilted and jammed on its bolts. A small tilt and a strong pull from a drillstring or crane jams the flange, resulting in a long shift to release it. ThinJackGAP reduces the likelihood of this happening by displaying the real-time gap measured around the flange circumference. Other gap-measuring systems require the measurer to move around pipework and obstructions on a crowded well deck to measure the gap. This slows down the flange separation and increases uncertainty regarding the point at which the flange is to be freed. The system displays the gap at several points on the flange circumference next to the separation-system operator, who may be 5 to 10 m from the flange.