Low-headroom hoist used in BOP handling operations provides lifting power and control where installation space is limited.
On the Maersk offshore rig, Guardian, four J.D. Neuhaus (JDN) type EH50 air-operated monorail hoists are incorporated into a blowout preventer (BOP) handling unit that provides synchronized lifting and handling during pre- and post-drilling operations. Two hoists are mounted on each of the unit’s twin parallel overhead rails, with each hoist providing 50 metric ton load and 20-m lift capacities for between-deck operations. Operating together, the two sets of hoists provide a combined lift capacity of 200 metric tons. Whether all four hoists are used together, individually or in pairs, synchronized operation of all linear movement and lifting operations is handled by multi-function controllers that incorporate a main-air emergency stop as well as load monitoring.
A large offshore crane system was constructed by J D Neuhaus to comply with offshore duties that include operating at temperatures down to –20° C in turbulent weather conditions and at inclines of 3 deg. from the horizontal with the crane loaded or 27 deg. when unloaded. The semi portal, A-frame design supports twin overhead horizontal track beams, each fitted with a single hydraulic EH 40-H hoist unit. The hoists can be operated individually or simultaneously from one controller. Working together, they provide a total lift of 80 metric tons, with a 12-m lift height over a 7.5-m span. To cover additional operational and service requirements, the company also supplied a JDN 6 TI-H hydraulic hoist with six metric ton lift capacity.
