The US National Transportation Safety Board (NTSB) has determined that the probable cause of the overturning of liftboat Ram XVIII (IMO 9769453) on November 18th 2018 in the Gulf of Mexico about 15 miles south-southeast of Grand Isle, Louisiana, was an industry practice of not regularly providing liftboat operators with adequate information about the seafloor composition. This resulted in the instability of the port leg due to unidentified conditions/hazards in seabed composition near the port leg landing site.
After the Ram XVIII overturned in West Delta Block 68, five crewmembers and 10 offshore workers abandoned the vessel and were rescued. Three personnel suffered minor injuries during the evacuation. An estimated 1,000 gallons of hydraulic oil were released. The vessel was declared a constructive total loss at an estimated $1,140,000.
The mate, master, and Aries Marine Operations Manager all described the West Delta area of the Gulf of Mexico as a “bad area” to work due to the soft bottom. Previously in his career the master had refused to work at locations due to previous landing impressions (can holes), losing his job at least once due to such a refusal. He told investigators that he had placed legs in a can hole only two other times in his 34-year career.
Despite his experience, and although he had never been to this platform before, he “felt good” about the location. He also stated the can hole nearest the port leg was far away, and “…there’s no way that leg slid into the can.” The weather was “slick calm” with no wind, and the elevated vessel was not rocking or swaying before the accident.
Aries Marine and Fugro management told investigators that can holes can fill in after 20 years or so, depending on soil and proximity to rivers. Fugro maintained this data on behalf of the block lease holder. Fugro proposed a landing location and asked for Aries’ input, but the final location was at the master’s discretion.
According to the master, jack-up MODUs, which are much larger than liftboats, get core sample and soil data with predicted penetration before they preload, which allows them to calculate the depth at which the legs should penetrate the seabed. According to Fugro, this information is sometimes required by the Bureau of Safety and Environmental Safety and/or insurance contracts, but was unavailable to the Ram XVIII as a liftboat.
2015-built, USA-flagged, 500 gt Ram XVIII is owned and managed by Aries Marine Corporation of Youngsville, Louisiana, USA.