The harbormaster at the port of Hobart, Tasmania has determined that the Antarctic research vessel NUYINA is too beamy, too prone to drift in a turn, and too affected by windage to safely pass under the Tasman Bridge. This leaves Nuyina without access to her local fueling pier, even though it is just two miles north of her home base.
Though the vessel is capable of walking a few meters at a time in DP mode, using her tunnel thrusters to control course and heading, the harbormaster has determined that the NUYINA is not able to safely make the outbound journey under the bridge because the ship would drift too much in a dynamic turn.
There is a relatively sharp bend approaching the navigation span when outbound. After running the scenario in a simulator, the concern is that NUYINA might not be able to line up onto the span after making the turn. “The risk is always a loss of control,” the harbormaster told Australian outlet ABC. “The vessel has a significant amount of drift and side slip. The vessel is perfectly suited for straight line work, perfectly suited for ice operations. It is a very powerful ship. But when you put that vessel into a dynamic turn, it slides.” He noted that the Nuyina is about 30 feet wider than originally specified. The vessel also has the most sail area of any ship that has ever requested permission to pass, and wind was a concern.
Lacking viable barge or truck options to bring the bunkers to Nuyina, the crew will have to bring Nuyina all the way to Burnie for fuel - adding an extra 300 nautical miles each way onto science voyages to Antarctica. There is a historical precedent behind the harbormaster's caution. In 1975, the bulker Lake Illawarra struck the Tasman Bridge and destroyed two pylons. A 400-foot section of the concrete bridge deck fell on the ship, sinking it and killing seven crewmembers. The wreck and the original bridge deck remain on the bottom of the channel as a warning.
NUYINA is a DP2-classed research vessel with a combined diesel-electric and direct-drive diesel (CODLAD) propulsion arrangement. This complex, redundant system has little resemblance to a merchant vessel's single two-stroke engine: Nuyina's powerplant couples two main engines and four auxiliary generators to two shafts, each with variable-pitch propellers. Six tunnel thrusters (three forward and three aft) provide for stationkeeping in conditions up to sea state 4.
The bridge holdup is the latest in a string of setbacks for NUYINA. The futuristic, $500 million vessel suffered an electrical fault on her delivery voyage to Hobart in October 2021. Two months later, her maiden scientific voyage was delayed after issues were detected in the alarm and monitoring system software. In April 2022, she headed for Singapore for planned maintenance and repairs to address issues with propulsion system couplings. A shortage of spare parts meant she missed the bulk of the 2022-2023 Antarctic season.
Source : MAREX