Robot to move a support platform along a flange connection

A robot to move a support platform along a series of nuts pre-screwed on bolts arranged in a linear or in a curved flange connection, which bolts project from the nuts pre-screwed in substantially a nut plane by a projection length, the robot comprising:

• a drive to move the robot along the flange connection,
• wherein the drive comprises at least one drive element and holding means both connected to the support platform, wherein:
• the at least one drive element comprises a motor built to drive engage means that engage into a space between neighboring bolts of the curved flange connection to move the robot;
• the holding means comprises at least one pair of guiding rails connected to the support platform at a distance from each other of more than a diameter of the bolts and less than a width across flat of the nuts and projecting more than the projection length from the support platform.