An apparatus comprising: a tool system configured to perform an operation at a location on a structure; and a movement system configured to move the tool system along an elongate frame on the structure to the location, wherein the movement system comprises: a locomotion system configured to move along the elongate frame, the locomotion system comprising: a number of rollers (320, 322) configured to contact the elongate frame; and a number of motors (316, 318) configured to turn at least one of the number of rollers such that the movement system and the tool system move along the elongate frame; and a clamping system (134, 328) configured to attach the locomotion system to the elongate frame, the clamping system comprising: a first guide comprising two structures (406, 408) and, on each of the two structures (406, 408), a bearing (410, 411) comprising a sphere (412, 413); a second guide comprising a further structure and two wheel assemblies (416, 418), each wheel assembly comprising a wheel (600, 604) and a further sphere (602, 606), the wheel assemblies (416, 418) being configured to contact the elongate frame; and an engagement system. a tool system configured to perform an operation at a location on a structure; and a movement system configured to move the tool system along an elongate frame on the structure to the location, wherein the movement system comprises: a locomotion system configured to move along the elongate frame, the locomotion system comprising: a number of rollers (320, 322) configured to contact the elongate frame; and a number of motors (316, 318) configured to turn at least one of the number of rollers such that the movement system and the tool system move along the elongate frame; and a clamping system (134, 328) configured to attach the locomotion system to the elongate frame, the clamping system comprising: a first guide comprising two structures (406, 408) and, on each of the two structures (406, 408), a bearing (410, 411) comprising a sphere (412, 413); a second guide comprising a further structure and two wheel assemblies (416, 418), each wheel assembly comprising a wheel (600, 604) and a further sphere (602, 606), the wheel assemblies (416, 418) being configured to contact the elongate frame; and an engagement system. a locomotion system configured to move along the elongate frame, the locomotion system comprising: a number of rollers (320, 322) configured to contact the elongate frame; and a number of motors (316, 318) configured to turn at least one of the number of rollers such that the movement system and the tool system move along the elongate frame; and a number of rollers (320, 322) configured to contact the elongate frame; and a number of motors (316, 318) configured to turn at least one of the number of rollers such that the movement system and the tool system move along the elongate frame; and a clamping system (134, 328) configured to attach the locomotion system to the elongate frame, the clamping system comprising: a first guide comprising two structures (406, 408) and, on each of the two structures (406, 408), a bearing (410, 411) comprising a sphere (412, 413); a second guide comprising a further structure and two wheel assemblies (416, 418), each wheel assembly comprising a wheel (600, 604) and a further sphere (602, 606), the wheel assemblies (416, 418) being configured to contact the elongate frame; and an engagement system. a first guide comprising two structures (406, 408) and, on each of the two structures (406, 408), a bearing (410, 411) comprising a sphere (412, 413); a second guide comprising a further structure and two wheel assemblies (416, 418), each wheel assembly comprising a wheel (600, 604) and a further sphere (602, 606), the wheel assemblies (416, 418) being configured to contact the elongate frame; and an engagement system.