When the frigate Taylor ran aground while pulling into Samsun, Turkey, on Feb. 12, 2014, the ship was well right of track and nobody had taken a fix in over six minutes — a fix interval for open ocean, not a transit into an uncommon port.
It is the most telling of many findings in a Navy investigation that is almost a textbook example of how things can go wrong in a hurry during a navigation detail.
The ship was on a security cooperation mission for the Winter Olympics in Sochi, Russia, at the time and the grounding was a high-profile embarrassment for the Navy.
"However, after collecting all the written statements prior to the interviews, and recreating the ship's plot based on the position logs, I started to question the initial reports," the investigating officer wrote. "The evidence started to indicate the ship actually hit the sea floor, possibly outside of charted safe waters."
The grounding cost the commanding officer, Cmdr. Dennis Volpe, as well as the ship's navigator and assistant navigator their jobs. Volpe was held accountable at non-judicial punishment, as was the NAV and assistant NAV, but the investigation did not specify the charges.
The guided missile frigate USS Taylor (FFG 50) steams in the Black Sea May 11, 2014, while conducting a tactical maneuvering exercise with the Turkish navy.
Photo Credit: Lt. j.g. David Hancock/Navy
The ship's executive officer, Lt. Cmdr. Joel Rodriguez, was given administrative counseling for failing to properly supervise the navigator but was not punished.
Multiple points of failure
The investigation showed that combat only calculated set and drift once during the transit. The bridge team claimed to have calculated set and drift 15 to 20 times during the transit, but the deck log showed the last set and drift calculation more than five hours before the grounding.
Instead, combat was also plotting GPS fixes. The team plotted several fixes incorrectly during the transit — critically, the last fix taken before grounding was about 220 yards off and well south of the dangerous shoals, according to reconstructed charts provided in the investigation.
The investigation found that the bridge was not running visual fixes, which shoots lines of bearing from major visual landmarks to the bridge to triangulate the position. The ship was relying almost solely on GPS for navigation and, investigators said, GPS was only accurate to within about 27 yards, something for which the ship failed to account.
But if the ship had taken the fix at 7:21, it would have seen that the ship was then 30 yards left of track, according to a reconstruction based on a GPS device used on board, the report said.
Both the combat and bridge watch teams told investigators that 1,000 yards from a turn, the ship goes to constant fixes until the turn is made, then they return to the regular position fixes. That works when the ship is traveling at a healthy 12 knots in the channel. But the ship had slowed to six knots because of its vicinity to shoal water, which meant that it took several minutes to close the 1,000 yards to the turn.
Investigators say the ship should have taken the fixes at 7:21 and 7:24. And while combat claimed to have taken a fix at 7:24, the investigation states that "the ship did not correctly plot any fixes between 7:18 and 7:25, the time of the grounding."
David B. Larter was the naval warfare reporter for Defense News.