Down the mouse hole! The downhole logging tool string is assembled from bottom to top and can be made up of one to six different types of logging tools, depending on the data to be collected. When the tool string is fully assembled, it can be as long as 40 m (131 ft). Because it is so long, it is lowered into the “mouse hole” (a steel tube that penetrates the drill floor) during assembly for easy handling when maintenance and adjustments need to be performed. Eventually the fully assembled tool string is lowered all the way through the drill pipe to the borehole. The information transmitted back to the surface from the downhole logging tool string is used to augment data from cores recovered during drilling operations. On the deck of the JOIDES Resolution, Siem Offshore crew members Manuel Cabusa (Floorman), Perfecto Cruz (AB Seaman), Ricardo L. Belda (Assistant Driller), Bonifacio Agonias (Assistant Driller), and Jefferson Manuel (Floorman) ease the partially assembled downhole logging tool string into the mouse hole. (Credit: Bill Crawford, IODP/TAMU) [Photo ID: exp351_052] Back to expedition photos.