Tanker Sola and Norwegian navy frigate Helga Ingstad collide off Norway

There is a lot that went wrong this situation. Although I am also questioning VTS to some regard, I believe implementing a ‘Smart VTS’ is not going to prevent collisions like this from happening. I feel this is part of the reason it has been in discussions for so long but has not actually been implemented. Sometimes eliminating the human aspect isn’t always the best choice but in cases of incompetence or complacency, perhaps these technological advances are more appropriate. It’s a fine line to walk.
I know there are circumstances when a VTS operator is requested to not pass navy ships or coast guard ships as traffic. It is very common… and for VTS Zones that do not have radar, the operator has to solely rely on AIS or reports from other vessels. This makes it difficult to pass traffic because the operator has no way of knowing where these ships are, so how can they warn vessels of a potential collision? It’s mind boggling that all VTS Zones are not radar equipped. In this situation though, I don’t believe that to be the case and I agree that VTS probably could have done something more for alerting.

At short distances no ship is really stealth, at long distances with much weaker echo signals they are better protected. The fieldstrenght of a radar signal decreases with the square of the distance traveled. The parabolic disk antenna midships on top of the wheel house is a perfect reflector for radar frequency signals! The picture shows what the Sola TS would have seen storming at them if it had been daylight.

All the angled plating is a good measure for deflecting away radar signals.

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The fact that the frigate was not transmitting AIS was a major factor here. Aside from not being detected it resulted in wasted time in communications.

Had the Tanker Sola seen a name they could have contacted her direct with a simple message, “I am dead ahead of you”. As it was the Sola had to communicate via the VTS which was little help.

More efficient communications would have given the frigate more time to understand the situation. About two minutes was lost establishing communications.

I cannot understand why VTS simply didn’t tell HI to slow down a little when passing Sture port/oil terminal, where Sola TS was departing. But maybe I am influenced by my service in the Swedish Royal (Kungliga) Navy (Flottan) a long time ago.

The HI can stop from 22 knots in about 4 times her lenght = 134 m x4 = 536 meter , at 17 knots should be less. With 17 knots she is traveling 525 meter a minute.

But it isn’t. It’s a perfect reflector for focusing incoming radar onto the antenna feed horn, not back to the sender. You want a corner reflector for that.


I would imagine that in case of such an exercise, there would be someone sitting in corner with access to AIS i radar and monitoring situation just to prevent such an situation.

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Yes, you are right, a incoming radar signal would be deflected by the parabolic dish to the focal point of the antenna which is the desired situation for receiving signals. At most, seen the short distance and the dead ahead situation, it could maybe overload or block the receiver’s front end.

AIS would solve most of the problem, but these stealth ships should also have something like a RACON that would give a clear indication on the radar of the presence, size, aspect, and high speed of these ships.


That dish is a Mark 82 fire-control radar for missiles, similar to the Mark 81 shown here.


A simple solution to make a stealth vessel more visible on radar when they want to would be to hang up a radar reflector on either side on the vessel’s signal mast. Low-tech but efficient and cheap.


Or an active transponder for S and X bands.

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I favor the active anti-stealth signals approach. We need lots of warning when the Navy is near.

From a security perspective, variable active signals would also mask the effectiveness of the stealth capability. It makes no sense for the Navy to be steaming around and letting the enemy develop the “stealth fingerprint” of each ship.

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A good idea! A RACON that when triggered by a Radar would transmit the Morse Code letter U meaning; «You are running into danger» :smirk:

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As far as I am aware, Norway has never been at war with Russia and I see no reason at all why Norway has a Royal Navy to defend itself 2018. Against who? Russia? Germany? Sweden? So the Norwegian Royal Navy is a joke and it is the proximate cause of the incident we discuss. The sailors on HI were just a bunch of idiots employed to keep the Norwegian flag flying and they didn’t even know how to navigate in night darkness. Nobody on the bridge incl. the OOW was capable of anything. Of course Norway has a land border against Russia up north but it is not backed up by barbed wires, land mines and automatic guns like at North Korea. So let’s face it. To avoid Royal Norwegian warships being sunk by merchant ships, just close down the Royal Norwegian Navy completely and save plenty money. Concentrate on fishing and merchant shipping. It is more fun.

You make less sense than even normally.
Maybe Sweden should shut down their army, navy and air force as well.
As far as I know Sweden hasn’t been in a war with Russia or anybody since the Napoleonic war.
And their navy is still trying to find the submarine that alleged entered their waters several years ago. Could it be because they no longer have steady geniuses like you in their midst??

I can agree that Norway doesn’t have any enemies and that it is very unlikely that Russia should attack anytime soon.

The frigates were intended for NATO service, not for coastal defence, which is done by the smaller and faster Corvettes that is able to operate much more efficiently and stealthily in coastal waters.


9 posts were split to a new topic: Frigate Helga Ingstad Design - Damage Survivability

2 posts were merged into an existing topic: Why did my post get deleted?

I said that Mk 82 dish forward is fire control radar – more properly, it sends out a beam that illuminates the target with coded pulses that the missile can recognize and home on.

The salvage operation explained in this VG.no article:

As usual it is written by someone with limited knowledge of the subject but, with a little good will, it is understandable and the sketches help.

PS> Google translate doesn’t help the clarity either.

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