A mandrel segment loader provides a reliable means of assembling the segments of a large multi-piece mandrel designed for the lay-up of composite materials in the manufacture of large structures such as one-piece fuselage barrels for wide-body aircraft and can also be used for removing the mandrel from the finished fuselage barrel by disassembling the segments. A fitting is on the distal end of the shaft, the fitting having an aperture formed therethrough, the aperture axially aligned with the bore of the lumen and in communication with the opening formed in the shaft. Thus, the breakdown voltage at the junctions between the extracting regions and the sourcedrain regions is increased and a parasitic bipolar effect is suppressed without breakdown between the extracting regions and the sourcedrain regions.