The sinking of the Norwegian frigate Helge Ingstad was caused by confusion among the ship’s crew, leading them to think that an approaching commercial tanker was actually a stationary object. In the collision’s wake, a design defect doomed the ship by letting in water that worsened flooding. That’s the preliminary assessment by the Accident Investigation Board Norway, which is looking into the incident that sank one-fifth of Norway’s frigate fleet.
The preliminary report, shared by USNI News, is based upon interviews with both the Norwegian Navy frigate Helge Ingstad and the civilian crew of the tanker Sola TS. It’s also based on data from the Ingstad, voyage and bridge audio from Sola TS, and data provided by the Norwegian Coastal Administration. The collision took place on November 8 at 4:01 a.m. local time, outside the Sture oil terminal off the coast of Norway.
According to the report, Helge Ingstad was on a routine training patrol, headed south along the coast near Bergen. The 5,290-ton warship had its navigation lights on and was visible on radar, but was not transmitting on the AIS ship positioning system. At 3:40 a.m. local time, a new navigation officer started a shift, and the crew noted a cluster of lights in the distance it took as a single object onshore. In reality, the lights were both the Sola TS and the Sture oil terminal.
At 3:45 a.m., the tanker Sola TS left the Shure terminal and proceeded in the direction of the incoming Helge Ingstad. Sola TS, under the control of a shore-based pilot who had boarded to steer the ship safely out of the waterway, noticed Helge Ingstad but could not identify it. Neither did the local vessel-tracking service whose job it was to monitor local maritime traffic.
With Helge Ingstad growing close, Norwegian authorities advised Sola TS the incoming ship was likely the Ingstad. The crew of the commercial ship attempted to contact the frigate and request that it turn to starboard to avoid a collision. Helge Ingstad, for its part, thought it was talking to another ship entirely, and that if it did turn to starboard as requested, it would run into the lights onshore. In reality, those lights were Sola TS. To make matters worse, Sola TS’s use of bright deck lights made it impossible for the warship’s crew to see its navigation lights, which would have clearly identified it as a ship.
By 4:00 a.m., the crew of the Ingstad realized what was going on and the frigate quickly took emergency evasive action. Unfortunately it was too little too late, and the two ships collided. Helge Ingstad lost control of rudder and propulsion, and the ship sailed on out of control for ten minutes. At 4:11 a.m. local time, Ingstad collided again, this time with the shoreline, running aground.
Ingstad suffered flooding in three of its watertight compartments, but the crew believed they could keep it afloat despite the damage. Unfortunately, water from the flooded aft generator room was quickly pouring into the gear room via the hollow propeller shafts, and from the gear room the water flowed into the forward and aft engine rooms. This doomed Ingstad’s ability to stay afloat, ultimately leading to the ship’s sinking. The AIBN report warns that this is a “safety critical issue” that somewhat ominously “must be assumed to also apply to the other four Nansen-class frigates."
The preliminary report states “the accident was not caused by any single act or event, but can be explained by a series of interacting complex factors and circumstances.” Many minor mistakes, such as the Ingstad’s lack of transmitting on the AIS ship-tracking network and use of deck lights on the Sola TS, combined with major ones particularly the Ingstad’s crew’s mistaking a commercial oil tanker for a shore-based object, added up to create a catastrophic incident. In other words, there is plenty enough blame to go around for everyone, though it sounds as though the Norwegian frigate's crew deserves the lion’s share.
Source: Popular Mechanics