The collision between a tanker and the Norwegian frigate Gelde Ingstad on November 8 to the west of the Nordic country was the result of "a human error," according to an internal report by the Spanish Navy.
This document, advanced by Abc, contradicts the Norwegian Accident Investigation Commission (AIBN) that in its preliminary conclusions blamed last Thursday the sinking of the warship to "safety critics" failures in the design of the Spanish public shipyard Navantia.
While the Norwegian commission went on tiptoe about the causes of the disaster, limiting itself to pointing out that "it was not caused by an isolated event, but by a series of complex factors that interacted with each other", and suggesting that the frigate could confuse the lights of the tanker with those of the loading dock, the note of the Spanish Navy details, with the information available, a series of alleged breaches of the navigation rules.
He explains that the frigate sailed "at a very high speed" (17,4 knots), despite traveling through the interior of a fjord; the AIS system (vessel identification) was not activated; he ignored the calls of the oil tanker to throw to starboard (right), as it corresponds when two ships are of front; he did not use emergency braking (crash-stop) and maneuvered too late to avoid the collision.
The excess of confidence and relaxation "could have a negative effect" on the decisions made by the crew of the frigate, "who returned from almost a month of maneuvers" and was already close to its base, explains the note from the Navy.
The central point of the report refers, however, to the alleged lack of tightness of the frigate built by Navantia which, according to the Norwegian commission of inquiry, caused the flood to extend longer than expected, causing its collapse.
According to the Norwegian commission, the crack opened by the collision with the tanker caused the flooding of three of the 13 compartments of the frigate, but later it was noticed that the water was flowing through the hollow of the propellers, flooding a fourth compartment and forcing to evacuate the ship. The extent of the flooding inside the vessel would be due to its "lack of tightness".
However, from the analysis of the images of the frigate, the Spanish Navy indicates that the visible crack is 18.2 meters (15% of the length), with three compartments flooded. But he adds that probably under the waterline was affected a fourth compartment and up to a fifth, due to another crack that would explain the presence of aviation fuel in the sea.
The design requirements of a ship with these characteristics force it to stay afloat with a crack of up to 15% of the length, so that only the visible damage was at the limit of what was tolerated. "Based on the behavior of the frigate after the collision, it is concluded that it meets the survival criteria […] since the dimensions of the damages produced exceed the limits required in its construction and even its 134 crew members could be rescued, "he says. "Any ship with similar characteristics would be unable to control the flood."
The report leaves the question of whether the frigate's commander applied the Zebra procedure before entering the fjord, which reinforces the sealing of all the compartments below the waterline.