Stridsbåt 90 H(alv) (Strb 90 H; CB90) is a class of fast military assault craft used by several countries after being originally developed for the by . Its name means Combat Boat 90 Half; the 90 refers to the year of acceptance (1990) and Half refers to the fact that it can carry and deploy a half platoon of amphibious infantry (18 men) fully equipped. The CB90 is an e.
[pdf] In a drilling rig, the drill line is a multi-thread, twisted wire rope that is threaded or reeved through in typically 6 to 12 parts between the traveling block and crown block to facilitate the lowering and lifting of the drill string into and out of the wellbore.
[pdf] Drill stems must be designed to transfer drilling torque for combined lengths that often exceed several miles down into the , and also must be able to resist pressure differentials between inside and outside (or vice versa), and have sufficient strength to suspend the total weight of deeper components. For deep wells this requires tempered steel tubes that are expensive, and owners spend considerable efforts to reuse them after finishing a well.
[pdf] 
