Zentech’s new R-550D jackup drilling rig design is a high-capacity, extended-reach cantilever rig, rated for 3,500 kips combined drilling load with extended reach to 80 ft aft of the transom. The R-550D features an operational variable deck load of 11,000 kips The Zentech designed and patented Zenlock System provides enhanced rig safety and ease of operation. This unique leg-to-hull fixation system is already under construction for R-550D rigs being built for Alliance Offshore Drilling. The R-550D features 4,220-bbl active/reserve mud pits configured for dual-fluid operations, along with three mud pumps, each 2,220 hp or equivalent. Living quarters can accommodate more than 150. Utilities and drains are configured for zero discharge. The R-550 is designed for closed-loop or air cooling of all equipment. The rig features a high-speed preload system for minimized mobilization time, as well as enhanced jacking capacity with 54 pinions allowing jacking with full preload (70,000 kips) in addition to normal jacking of 54,000 kips. The R-550D has been designed to virtually eliminate rack phase differential (RPD) problems with an allowable spud-can deflection of more than 14 ft and RPD values in the range of 9 to 10 in. with nominal fixity. The rig handles drilling depth of 35,000 ft (9144 m).