Navy Faults Navigational Procedures in Crash of Sub
| 4/9/2005 | ROBERT A. HAMILTON
By ROBERT A. HAMILTON
Day Staff Writer, Navy/Defense/Electric Boat
Published on 4/9/2005
A Navy report on the submarine that hit a sea mount in the Pacific three months ago will conclude that there was a serious breakdown in navigation procedures that led to the accident, which killed one sailor and injured more than half the crew, Navy sources have told The Day.
The report, which could be released as early as this month, will cite problems with the USS San Francisco's chart preparation methods and, more seriously, the crew's failures to recognize specific warnings that the submarine was headed into trouble.
Soundings showed the bottom was more than 1,200 feet shallower than on the charts that were in use, a difference of more than 20 percent, the sources said. In addition, the ship's fathometer showed the water was shoaling, or getting more shallow with each reading, over an extended period of time, the sources said.
Either one of the warnings should have prompted the crew to slow the submarine down and proceed far more cautiously, the sources said. Instead, the ship plowed into an underwater mountain that was nearly a sheer cliff at a speed of about 30 mph.
In addition, the navigation team was not laying out the ship's projected track far enough ahead of the ship's actual position to determine whether it was sailing into safe water, a particularly dangerous practice in the island-studded area of the Pacific where the San Francisco was operating, the sources said.
One of the sources said he was on a submarine that nearly ran into another uncharted sea mount, but the navigation team recognized and responded to the early warnings and avoided grounding.
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The San Francisco left its homeport of Guam on Friday, Jan. 7, headed for Brisbane, Australia. The next day, a little more than 400 miles southeast of Guam, as sailors were sitting down to lunch, it slammed into the sea mount in an area where official Navy charts list 6,000 feet of water.
Three of the four ballast tanks in the bow were shattered, the sonar dome and sonar sphere were smashed, and a bulkhead at the front end of the ship was buckled. But the crew got the ship to the surface and rigged it to make the trip back to Guam.
Machinist Mate 3rd Class Joseph Ashley was killed when he struck his head on a large pump. Almost two dozen others were injured so badly they could not perform their duties, though within days most were treated and released from a hospital in Guam. Most of the crew were treated for some injury.
At an admiral's mast in February, the captain was found guilty of putting the ship into danger and was relieved of command. Last month, six more crewmen were cited for putting the ship into danger or dereliction of duty, and received punishments that included demotions and letters of reprimand.
Almost immediately, attention focused on the fact that the mountain was not on the charts, and even some within the submarine community wondered whether the crew should be held responsible.
But the investigation showed that there were at least five notices to mariners, most recently in 2002, about a large patch of muddy water about three miles south of the sea mount that were not incorporated on the charts the San Francisco was using at the time, the sources said.
If the bottom had been as deep as the 1989 chart indicated, that muddy patch would not have appeared.
Certainly, incorporating notices to mariners on existing charts is arduous. On Feb. 5, for instance, the National Geospatial-Intelligence Agency, which produces map information for the military, issued a notice to mariners about the sea mount that the San Francisco hit.
That notice is 58 pages long and covers hundreds of changes worldwide, including four — the sea mount, an obstruction and two depth changes — on the specific chart, number 81023, the San Francisco was using when it ran aground. And it is one of 15 notices issued so far this year.
But submariners said no matter how cumbersome, a failure to adequately update the charts with the notices can put the ship in danger, as the San Francisco incident proved.
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The Navy has been criticized for not issuing updated charts if it knew of a possible hazard to submarine operations in the area. But updates are expensive and take time. The agency that would make the changes has been kept busy in recent years on other work, such as terrain mapping in Afghanistan and Iraq, where accurate maps are critical to land operations and cruise-missile strikes, the sources said.
There were other problems with the navigation practices on the San Francisco that might not have contributed to the accident, but which indicated a slackness that is unacceptable in the submarine force, the sources said.
The San Francisco was using a chart that showed the area in a large scale, which was convenient for the high-speed transit it was making but did not provide sufficient detail about other dangers in the area, the sources said.
And the submarine crew had not adequately projected the ship's intended track on its charts. One of the sources said it would not have been uncommon to have had the entire track to Brisbane laid out on the charts, and to brief the navigation team daily on the track for the next 24 hours, but the San Francisco had not met either of those standards.
Under submarine-force regulations, the navigation team might prepare the charts, but the captain, executive officer, navigation officer, assistant navigation officer, and senior electronics technician responsible for navigation would have had to review the voyage planning process, and signed the charts as acceptable.
Navy sources said putting your signature on that chart makes you personally liable for its accuracy, a responsibility that naval officers cannot take lightly.
In the crew's defense, it has been noted that the operational orders known as the Subnote, which was issued by Submarine Group 7 in Yokosuka, Japan, arrived at the ship only a short time before it was to leave.
The Subnote provides the submarine with several points where it must be and the time it must be at those points, provides an average speed of the transit and the submarine track. It also provides the submarine with a “moving haven,” an area where no friendly submarines will be operating and where the Navy will not be using subsurface hazards to navigation such as towed sonar arrays.
Having the Subnote get to the ship so late provided the ship little time to prepare, and the Subnote routed the ship through the area of the sea mount.
But that defense was dismissed at the non-judicial proceedings known as the captain's mast where the navigation team was punished, for several reasons, including the fact that if the submarine had insufficient time to prepare adequately, the captain should have asked for more time. And while the track is laid out in the Subnote, the crew must still follow safe navigation practices — if the Subnote called for it to transit an area of heavy boat traffic, for instance, the crew is expected to avoid hitting other craft, one of the sources pointed out.
The captain and navigation team were also held liable because San Francisco was making flank speed, or just about top speed for the submarine, through an area that it should have known was dangerous.
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Even more serious than them breakdown in the chart preparation process, the sources said, were the warning signs that were not heeded, particularly the soundings taken by the ship's fathometer. Just minutes before the crash, the San Francisco came to the surface to check its location on the Global Positioning System.
The submarine is also equipped with the sophisticated Ring Laser Gyro Navigator, so it knew its position with a high degree of certainty.
Yet where the charts showed 1,000 fathoms of water, the sounding showed less than 800 fathoms — still a huge safety margin below the keel, but a difference that should have caused the navigation team to recommend proceeding with caution.
In addition, the navigation team had noted for a lengthy period that the water depth was shoaling, or becoming more shallow.
The team apparently believed it was a faulty reading — moving through the water at 30 mph, fathometer readings can be inaccurate — and the team kept hoping that perhaps the next reading would correlate with the chart.
In retrospect, it's clear that the readings were accurate, the water was shoaling, and the San Francisco was heading for what was nearly an underwater cliff.