A data retrieval system has a data server, a co-presence server and at least one awareness co-presence client. The inspection system has two detection systems configured to detect radiation scattered from the person as the person moves along the pathway and an X-ray source positioned between the detection systems. The first network device specifies an external address of the third network device for the security association to the second network device, which stores the external address in a table. The tension bow applies tension to this part of the cover when tension bow is in either of the tensioning or non-tensioning positions. During the time movement, the player can combine the above action with further action by the player’s other hand. After setting of the grouting material and removal of the formwork a ring is placed on the surface of the set grouting material and a lower pylon segment is placed on the ring and connected thereto.