Norway has released its investigation report on the November 2018 loss of a frigate because of a collision. This accident involved the 134 meter long, 5,000 ton Norwegian frigate experiencing a glancing collision with a 249 meter long, 62,000 (displacement) ton oil tanker. The big ship had just taken on a load of oil and was departing the loading terminal when the accident took place. The collision, with the frigate running into the larger and slower moving tanker, took place at 4 AM on November 8, 2018. Seven of the 137 crew on the frigate were slightly injured and the damage incurred caused the frigate to sink near the shore. The tanker suffered minor damage and none of its 24 crew were injured.
The investigation confirmed that collision occurred because of inadequate training of the four man bridge team bringing the frigate through the Hjeltefjord fjord towards the port and near the Sure terminal the tanker was exiting. The local VTS (Vessel Traffic Service) station knew that both ships were moving but the frigate had its AIS (automatic information system) in passive (listen only) mode and frigate bridge team did not notice that the tanker was underway. The tanker was lit up, but so many tanker deck lights were on so the crew could make ready for open sea operations that the frigate bridge team could not clearly make out and interpret the navigation lights. If they had they would have realized that the tanker was moving towards them. Instead the bridge team assumed the tanker was stationary and all they had to do was steer past it. The bridge team on the tanker noted the approaching frigate but was unable to alert the frigate in time to avoid the collision. VTS did not note the collision course until alerted by the tanker and was also unable to alert the frigate in time to avoid what was a glancing collision that, in theory, should not have sunk the frigate.
The Norwegian frigate was not a victim of the notoriously bad weather in the North Atlantic (especially during Winter) or a direct collision. What sank the frigate unexpectedly was slight damage that the ship was designed to handle. But those safety features did not work. The collision revealed design defects in these new Nansen class frigates. The lost ship was nine years old and collided with a tanker for some immediately obvious reasons. The bridge watch made several mistakes (moving too fast, misidentifying other ships and general inability to deal with the situation) that led to the collision. The Nansen class ships were, on paper, difficult to sink. But a key safety feature (the stuffing boxes that sealed the bulkhead opening for the propeller shaft) did not work and the flooding spread to other parts of the ship that would have been watertight if the stuffing boxes had worked. This sort of thing has been encountered before, where ship design features that were supposed to prevent the spread of flooding but didn’t. The loss of the Norwegian frigate had many similarities with the loss of the Titanic in 1912. The Titanic was moving too fast in the North Atlantic and lookouts did not correctly report what was out there. There was ice that tore open the hull. The “unsinkable” design features should have kept Titanic afloat but did not work when put to the test. The more fortunate Norwegian frigate was near a port and its uncontrolled flooding on the frigate caused it to be grounded on a nearby shore. But the water damage inside the ship was widespread and the frigate was later declared a total loss.
The Accident Investigation Board issued a list of fifteen recommendations to avoid future incidents like this. The most important ones involved the training and supervision of the bridge teams, especially during potentially difficult (pre-dawn in a channel with other traffic) operations. Lack of veteran navigation officers and bridge crew means inexperienced officers were training young, sometimes conscript, sailors to perform bridge duty. These personnel had little experience working together, especially in difficult situations like a pre-dawn movement through an active shipping channel. A more experienced member of the frigate bridge team would have noted that the tanker was not stationary but slowly moving out of the loading terminal. The navy also depended too much on VTS, which was not closely monitoring ship traffic and them, and the tanker crew was handicapped by the frigate not having its AIS in broadcast mode. That would have shown the position and movement of the frigate. In turn, the inexperienced frigate bridge team did not think to contact VTS for updates. The frigate captain also neglected to schedule bridge team work hours so that poorly trained and sleep-deprived, crew would not be on duty for a dangerous passage. The blame was mainly on the frigate officers and the Norwegian Navy which did not recognize the danger of inexperienced bridge teams having problems in situations like this. This was very similar to what happened to cause two collisions of U.S. Pacific Fleet destroyers at about the same time. One of those collisions killed sailors. The Norwegian recommendations addressed all of this but it is up to the navy and port authorities to make adequate changes.