Helge Ingstad Collision Anaysis

some mathematics behind the collision


This article was linked in the one above.

The HELGE INGSTADT incident – a navigational assessment

From that article:

When considering collisions such as these, the first reference is always the IRPCS, the ‘Rules of the Road’.

I don’t agree that the COLREGS is the first reference. First is understanding the situation.

According to the reports the bridge team believed that the tanker was a “lighted object”. If the traffic situation was not understood by the bridge team how can they correctly apply COLREGS?


The accident will be re-enacted to throw more light on what actually happened:

The TS Sola and KNM Roald Amundsen will take part to make this as realistic as possible.

Curious. I donot quite understand what they hope to gain by a re-enactment of the collision which is not much more than a mechanical repeat. I am afraid that you cannot re-enact the situational unawareness, the (mis)interpretation of the situation on hand, in short the brain processes which took place in the heads of those on the bridge that night which ultimately led to this unfortunate incident.

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Watch change, fatigue, general inexperience (the failure to cross-check information) seems sufficient to explain this incident. However judging from the discussion here and elsewhere to both most members of the general public and professional mariners it still seems inexplicable.

Maybe the point of reenactment is not to understand but to convince, either one way or the other.

Perhaps they want to prove negligence on the part of the crew of HI.

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Dutchi is correct - the re-enactment of this collision is simply an exercise… nothing more than someone with a brilliant idea that in by doing so, light will be shed on what led to Helge Ingstad steering into T/S Sola.

The mindset of whomever was the dominant bridge officer on Helge Ingstad, as well and other HI bridge personnel and the T/S Sola bridge team too, can’t be realistically simulated. Therefore, why bother? Other than for someone or some group to be seen as being pro-active? No other reason makes sense.

Bottom line, only in relaxed environments, where selected, experienced mariners take part in separate, candid discussions with members of both vessel bridge teams can it be derived what were the real-time thoughts and actions of those involved. Those thoughts and actions could then be put into perspective and published for others to know how to possibly avoid a similar circumstance.

I believe that the point of the re-enactment was to get a feel for the sequence of events, overlaid on an accurate rendition of the visual circumstances. There’s an article in NRK this morning, with an interesting picture and a bit of video that goes a long way to describe the lighting conditions. Aside from that, it’s just a description of the events, so don’t bother with google translate.

Very interesting video. Clearly the lighting conditions may have had an impact in hiding the running lights of the TS SOLA. As a former bridge officer, I am almost ashamed to say it, but in these conditions the use of radar would have allowed better to see that the TS SOLA was indeed under way.

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There is nothing to be ashamed of for using all available means to fix position and aid in collision avoidance. Something as simple as true trails enabled on the radar and an EBL line can pay huge dividends in heavy traffic.


I agree but in this case the watch officers understanding was that they were meeting three ships more or less in a line port to port. That’s not heavy traffic but any measure.

In this case I would expect the watch offices were almost exclusively using visual and would depend upon CIC for the radar watch.

The two issues here are fatigue and the very recent watch change. The oncoming watch would need to very quickly disregard the understanding passed by the off-going watch.

Rule 2
(a) Nothing in these Rules shall exonerate any vessel, or the owner, master or crew thereof, from the consequences of any neglect to comply with these Rules or of the neglect of any precaution which may be required by the ordinary practice of seamen, or by the special circumstances of the case.
(b) In construing and complying with these Rules due regard shall be had to all dangers of navigation and collision and to any special circumstances, including the limitations of the vessels involved, which may make a departure from these Rules necessary to avoid immediate danger.

Rule 8
Action to avoid Collision
(e) If necessary to avoid collision or allow more time to assess the situation, a vessel shall slacken her speed or take all way off by stopping or reversing her means of propulsion.

Rule 7
Risk of Collision
(a) Every vessel shall use all available means appropriate to the prevailing circumstances and conditions to determine if risk of collision exists. If there is any doubt such risk shall be deemed to exist.
(b) Proper use shall be made of radar equipment if fitted and operational, including long-range scanning to obtain early warning of risk of collision and radar plotting or equivalent systematic observation of detected objects.
( c) Assumptions shall not be made on the basis of scanty information, especially scanty radar information.
(d) In determining if risk of collision exists the following considerations shall be among those taken into account:
(i) such risk shall be deemed to exist if the compass bearing of an approaching vessel does not appreciably change,
(ii) such risk may sometimes exist even when an appreciable bearing change is evident, particularly when approaching a very large vessel or a tow or when approaching a vessel at close range.

I’m not claiming that the COLREGS do not apply to this incident. What I mean to say is that an analysis based on the COLREGS doesn’t really shed much light in this case.

Otherwise the final report from the authorities would be a single line, “Had the Helge Ingstad altered to stbd and passed port to port the collision would have been avoided”.

I don’t think many experienced professional mariners would find that enlightening.

Yes, three northbound ships (really five if you include TS Sola and its tug) is not heavy traffic by any means, especially following a TSS. Yes, change of watch and nighttime is complicating things, but, hey, that is just part of the job (just like being rested before starting a night watch, and taking proper time to understand the naval situation before taking over …)

My impression of this accident is that the bridge crew of Helge Ingstad relied only on a visual watch. The spotted probably early the three northbound ships (Silver Firda, Vestris and Seigrunn). But, they did not realize that the bright lights next to the oil terminal were really from the TS Sola about to get underway. When they got VHF calls from the TS Sola asking them to pass on starboard, it reinforced their confusion. They thought the call was coming from one of the three northbound ships. They thought they should pass first the “oil terminal” before maneuvering.

If they had monitored AIS, they would have found that the TS Sola call was not from one of the three northbound freighters.

If they had monitored their radar, they would have spotted the TS Sola departure from the oil terminal.

Then, still plenty of time to figure out if they could pass the TS Sola red-on-red so between the tanker and the oil terminal. Or, they could also have made a sharp turn to port and pass all the northbound traffic green-on-green (that is the good thing about navy frigates: very quick speed and turning reactions)

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NRK reports that thee people have been formally suspected in the case:

Here’s a rough translation by yours truly:

Am I the only one who finds it just a little bit odd that the pilot on Sola TS was the most obvious suspect?

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From my point of view the question is are; excess speed, normal confusion, fatigue, watch change and inexperience sufficent to understand this incident?

Because of hindsight bias that question is impossible to answer, there might be another factor unknown to us or there may not be.

In any case hindsight bias is going to make a just adequate expanation seem to fall short because of how easy the problem is to solve after the fact.