... emergency response to main system failure, maximum drill string weight can be hoisted.4. Traveling block position automatic control ... rig drilling rig , drilling equipment ,drilling machine ,oil rig,oil equipment, rig equipment, tiger rig,low-temperature rig, land rig ,truck-mounted rig,mobile drilling rigrotary drilling rig truck-mounted drilling rig, Land Drilling Rigs,kazakhsatn rig ,russian rig ...