I do wonder: - Why approaching something thought to be a fixed construction didn't trigger any alarms, mechanical or mental? It doesn't matter if the "tanker"

I do wonder: - Why approaching something thought to be a fixed construction didn't trigger any alarms, mechanical or mental? It doesn't matter if the "tanker" was a stationary part of the harbour or a moving vessel because just looking at the change in their relative positions would have indicated a collision course regardless. - I suppose ships still have radars? Looking at a dot or an edge coming closer and closer on the radar screen should ring some bells. - The tanker had their identification transponder on as expected: why did not the military vessel get red lights flashing somewhere even if they chose to not turn on theirs? - Don't ships have any means to communicate emergencies? If the tanker couldn't contact the frigate by radio wouldn't the ship have deck lights or search lights or something that they could starting flashing, as a last resort, as soon as they observed that the frigate would in fact collide with the tanker's course? Heck, couldn't they even shoot flares at the frigate if that's really what it takes? In the air, accidents usually happen these days because of several things go wrong in sequence. Everything is basically covered for either in procedures or by technology but given enough unlucky sequential failures in various systems makes it possible for something fatal to happen, and sometimes it does. In contrast, and based on a couple of articles, this sounds like a trivial blunder. Is there a more comprehensive failure analysis still being worked on, and to be published later? EDIT: The tanker apparently did manage to contact the fregate by radio. And still they didn't "get it". I would like to see a more substantial breakdown of the causes rather than mere incompetence. Norwegians have lived and breathed the sea for ages, I generally do trust their ability to navigate a ship.