From the preliminary report:
The Voyage Data Recorder (VDR) from Sola TS has been secured and played back. It contains voyage data and audio recordings from the vessel’s bridge. Radar data and automatic identification system (AIS) data have been obtained from the Norwegian Coastal Administration. Data from the bridge of ‘KNM Helge Ingstad’ have also been retrieved and secured.
At around 03:40, the navigation officer coming on watch arrived on the bridge of ‘KNM Helge Ingstad’, went through the handover procedure and was informed about vessel traffic in the waters by the officer leaving the watch. The three northbound vessels were registered and plotted on the radar on board ‘KNM Helge Ingstad’. During the watch handover, an object with many lights was observed lying still just outside the Sture terminal.
At approximately 03:57 the (Sola TS) pilot observed the echo of a southbound vessel on the radar. The vessel was north of ‘Sola TS’. The pilot saw the vessel’s green light and that it would cross his course line, but did not have an AIS signal for the vessel.
At approximately 04:00, Fedje VTS called ‘Sola TS’ with the information that the vessel was possibly ‘KNM Helge Ingstad’. Shortly thereafter, the pilot called ‘KNM Helge Ingstad’ and requested it to turn to starboard immediately. The bridge crew on ‘KNM Helge Ingstad’ replied that they could not turn to starboard before they had passed the object they saw on their starboard side . Just after 04:00, ‘KNM Helge Ingstad’ was approximately 400 m from Sola TS. When ‘KNM Helge Ingstad’ did not change course, both the pilot and Fedje VTS called ‘KNM Helge Ingstad’ requesting the vessel to act. Shortly thereafter, ‘KNM Helge Ingstad’ carried out an avoidance manoeuvre, but it was too late, and the two vessels collided.
(end of quote)
The avoidance manoeuvre (900 meters from shore) was a port turn just in front of ‘Sola TS’, whose bulbous bow ripped open Helge Ingstad’s starboard underwater hull and whose anchor ripped open the war ship’s superstructure/deckhouse above waterline aft. It seems the Norwegian sailors didn’t have a clue where they were or what to do. I wonder what the Helge Ingstad’s hull damages below waterline looks like. However, from the report:
The AIBN’s preliminary assessment is that the accident was not caused by any single act or event, but can be explained by a series of interacting complex factors and circumstances.