Apparatus for positioning a derrick and associated drilling equipment over a marine drilling site

摘要

1,089,313. Earth-drilling. BETHLEHEM STEEL CORPORATION. March 1, 1966 [March 2, 1965], No. 8859/66. Heading E1F. Apparatus for positioning drilling equipment on a platform 3 over a marine site comprises a lower carriage 2 movable along rails 4 and a upper carriage 6 supporting a derrick (not shown) and movable along rails 7 mounted on the carriage 2. Each carriage is moved along its respective rails by means of hydraulically actuated cylinders 26 and pistons 27 operating in conjunction with a ratchet mechanism 33 which engages holes 25 in a flange 14 on each rail the ratchet being reversible to allow movement of the carriages in either direction along the rails. The rails 4 may have continuations on an adjacent structure to permit transfer of the equipment from the platform to the structure.