The evolution of liftboats took a big leap forward when Bollinger Shipyards (USA) delivered the L/B MYRTLE, a 137.5-foot liftboat to Montco Offshore (Louisiana, USA). Equipped with 245-foot legs, the self-propelled floating platform has the ability to work in water depths to 180 feet with a 15-foot air gap while lifting a total of 850 KIPS of variable load. What makes the L/B MYRTLE different from other liftboats is that it is equipped with a bow thruster and controllable pitch (CP) propellers for greater maneuverability and pinpoint positioning of the huge legs with oversized pads on the ocean bottom.
The vessel is equipped with 40 foot by 16-foot pads, much larger than those on other liftboats, to provide for greater bottom stability and greater deck loads. The L/B MYRTLE can also jack with a full pre-load and its pre-load system has quick acting stainless steel dump valves. It is equipped with three Nautilus cranes with 150, 50 and 25-ton capacities in an innovative configuration. The smaller crane is positioned on the starboard stern so that support vessels can tie-up to the liftboat and offload personnel, cargo, and/or fluids without hindering other work being done by the liftboat. The 150-ton crane has a 110-foot boom and is equipped with VHF radio, loudhailer, load indicator and boom-mounted video camera with monitor to assist when load hook-ups are out of the normal view of the operator.