Norway: one frigate downed

This night (04:00 local time) a Norwegian frigate returning home from the ongoing NATO exercise crashed with an oil tanker. Still we don't know much about the accident, but apparently the tanker came in slow speed from the starboard - escorted by tugs and with a pilot on the bridge - it seems quite so obvious that the oil tanker was not to blame. Perhaps the officers on the bridge, coming directly from a busy NATO exercise were tired?

Photo source: nrk.no

This frigate allegedly have all the top-notch equipment for locating enemy submarines and small patrol ships far away ... but a huge oil tanker with AIS responder turned on just in front of them to the starbord side was apparently invisible. Incredible.

The military ship did not have its AIS transponder turned on, it got turned on after the accident. On marinetraffic.com, the war ship apparently suddenly appears from nowhere. My colleagues were jokingly suggesting that the top-secret teleporting device was malfunctioning today, and that's the reason for the crash.

All personnel on the military ship were evacuated safely - except, some few got injured, two persons are held in the hospital at the moment. The frigate was taking in water fast, for a while news media reported that they managed to pump out more water than what the ship took in, but in the next moment the ship was sinking. They've managed to put it on shallow water so now it's grounded, though the terrain is steep and rocky so they have to actively keep it in place with tug ships to avoid it from sliding and sinking on deep water. There are some oil leakages on the water.

And the tanker? News media says very little about it, no photos of the damages, nothing. One could get the impression that the tanker just left on for their next port, unaffected by the accident. Though now it says in the news that the oil tanker is held back so the personnel on board can be interrogated by the police. According to marinetraffic.com the ship is going slowly forth and back in a holding pattern a bit on the outside of the most trafficated areas.

For reasons I don't understand, the oil terminal where the oil tanker came from, as well as quite some oil and gas production was halted for seven hours today due to the accident.

Another thought ... in my imagination war ships are robust things, built to sustain some damage and keep afloat even when it's damaged. The German battle ship Tirpitz was eventually sunk nearby my home during WWII, but it was a very hard job as the ship was nearly unsinkable. This modern frigate was apparently optimized for low weight and high speed, so while the tanker probably got nothing but some few dents and scratches, the military ship sunk completely.

The ship was very expensive when it was purchased, the estimated value of the ship is still very high - perhaps as much as 30000 BTC - and purchasing a new replacement ship would be very expensive. I suppose it's not a complete write-off, but renovating it will for sure cost a lot. I think the rational thing would be to just say ... "oh, we lost a frigate - that's bad" without following it with "let's buy a new one".

Main source: https://www.nrk.no/emne/fregatt-kolliderte-med-tankskip-i-oygarden-1.14284375

Update: the tanker allegedly has damages on the starboard anchor, meaning the ships probably met front-to-front. The dreaded weapon used by the oil tanker was probably the anchor - aka "the tin opener".

Update 2: Here is a close-up of the damages on the frigate

Image source: TV2.no

Update 3: Since there will be an official investigation, those who knows the details of the accident generally won't tell anything in the public. All the radio traffic is broadcast openly on VHF channels 16 and 80, which all ships should listen to, so it's now well-known that both the tanker and the traffic central was repeatedly contacting the frigate telling it that it was on collision-course, to which the frigate responded: "we have full control of the situation". My speculation: although the military exercise was officially over, they were still in "exercise mode", and they wanted to go quite close to the tanker in good speed to practice navigation. They went for a starboard-to-starboard-pass with very small margins. The tanker, in the meanwhile, turned full starboard (as the recommended international practice is to always pass port-to-port in such situations) to avoid colliding. Now the tanker is a slow sluggish thing while the frigate is fast and easy to maneuver, so this shouldn't really matter much ... but with too small margins and probably quite some of the people on the bridge of the frigate being excessively drowsy at 04:00 in the night, it's sufficient to make a close encounter turn into an accident.

Update 4: There are also speculations in the media that the accident may have happened because the frigate was invisible on the radar and had no AIS turned on (and for all we know it may even have had the navigation lights off). I think it doesn't matter at all - even if it was very visible, it was fully the responsibility of the frigate to avoid crashing - and with the AIS off and because it's slightly stealthy on the radar, it should take even more responsibility to avoid crashing with civilian ships and boats. There are reports in the media that the frigate indeed was invisible on the radar - but stealth technology only works that much, both the tank ship and the traffic control had good enough radar equipment to see that the frigate was on collision course.

Update 5: Even though nobody involved in the accident is allowed to talk with the media, some few things are leaking out, i.e. by family members posting on Facebook. The hole extends into several cabins where personnel were sleeping. It was a very close call, there could easily have been some fatalities here.

Update 6: The visible damages we can see above was not in itself the reason why the ship sunk. Look at those damages at the tanker:

Photo source: https://www.vg.no/nyheter/innenriks/i/9m1g99/milliardfregatt-med-massive-skader-etter-kollisjon-som-en-rambukk

One can see how high above the water line that "tin opener" (anchor holder) is - so those damages was not what caused the frigate to sink.

Such big ships have a big bulbous bow right under the water line, probably the frigate hit this one first, causing massive unseen damages under the water line.

Update 7:

NATO confirms the frigate was in navigational training, and the full VHF records have been published by the media. The frigate never said it has control of the situation. Both the traffic management and the frigate sounds utterly confused, probably the personnel on the tanker is the only ones being truly awake at 04:00. Speculation: The frigate was having all electronics turned off for excersise reasons and had no clue about its location nor what it was colliding with.