thedrifter
01-16-07, 01:31 PM
There but for the Grace of God
By Raymond Perry
In the early evening hours of January 8th, 2007, the USS Newport News, a US Navy Fast Attack Nuclear Submarine was sucked into a collision with the Mogamigawa, a supertanker owned by Kawasaki Kisen Kaisha Ltd., a Japanese flagged Very Large Crude Carrier (VLCC) based in Tokyo, Japan. The USS Newport News was operating fully submerged at a routine operating depth for such operations. Both ships were eastbound departing the Straits of Hormuz.
The Straits of Hormuz carry a vast quntity of the worlds oil in a huge number of ships. Traffic is very heavy there. There is a “Traffic Separation Scheme” in place that separates opposing shipping traffic to reduce the possibility of collision in this vital, and narrow, passage.
The USS Newport News and the Mogamigawa were travelling in the same direction so the “Traffic Separation Scheme” did not offer any protection to them. Since the USS Newport News was fully submerged the Mogamigawa was not even aware of her presence and could not take action to avoid the collision.
Why did the USS Newport News not take action to avoid the collision? The answer lies in the contruction of the Mogamigawa. These VLCC ships are huge, in this case 300,000 tons at full load. The Mogamigawa was carrying a full load.
There is so much ship, and crude oil, between the engineroom and propeller, the noisemaking regions of the ship, that anything in a narrow cone in the front of the ship will have no warning of its approach. This shielding effect is pronounced but is a quite narrow cone perhaps 5º and no more than 10º wide.
The next thing to be understood is that these VLCC ships are so large that their draft, the depth of their keel at full load, can be on the order of 120 feet or more. When this is combined with a narrow and shallow seaway, such as the Straits of Hormuz, the stage is set for a collision.
In this case the USS Newport News was certainly operating at what was considered a safe depth for normal operations. The final element of the collision was physics. When two moving bodies operate close to each other a suction is created, the venturri effect. This can then pull a smaller ship into a larger ship.
This same effect causes two ships conducting underway replenisment to have to steer courses a few degrees off what they would in open seas. If one observes two ships engaged in underway replenishment the sea surface between them will actually lower somewhat because of this effect.
The Mogamigawa was on a course nearly coincident with that of the USS Newport News. The Mogamigawa was likely travelling at a speed of 15 to 20 knots. This is a normal speed for VLCC’s in open waters. The USS Newport News must have been travelling less than this in order to be overtaken.
The venturri effect will suck the smaller ship into the larger ship regardless of the speed differential. The only other consideration is that of reduced control response at slow speeds. Any ship responds sluggishly at slow speed and it may be that the USS Newport News was operating at a slow speed with lesser ability to respond to the suction.
In the end the USS Newport News was in a difficult situation, she could not detect the oncoming Mogamigawa and so could not avoid the collision. The United States long ago accepted reponsibility, under the Rules for Avoiding Collisions at Sea, for collisions inherent in submarine operations.
An investigation will reveal whether ships company could have avoided the collision. This in turn will determine the fate of her Commanding Officer, Commander Matthew Weingart.
The Navy has directed a servicewide “Safety Stand Down” in the wake of this collosion whereby all ships, units, and squadrons stop all events and review safety procedures. This type of action is a way for an admiral to seem to be taking action when in fact little changes in the culture that drives accidents.
All these really do is turn down the heat on the admiral.
A “ Safety Stand Down” is a peacetime fiction of today’s military, this nation is at war.
Frequently Commanding Officers are relieved of command in ignominy after a collision or grounding. There are notable, but rare, occasions where this does not happen because the collision was truly unavoidable.
The Submarine Force will look carefully into what cues the sonar party had of contacts and find out if there were things overlooked that should have tipped the crew to the approaching Mogamigawa. The training and qualification of crew members will be scrutinized carefully to see if any crewmen were deficient in preparation for their watchstation.
Investigations are important, less because of potential culpability of crew members, but to refine Submarine Force training and become smarter so that this kind of collision is less likely to recur.
Should Commander Weingart be relieved of command because of this collision, Commanding Officers the world around will again remark, “There but for the grace of God...”
Ellie
By Raymond Perry
In the early evening hours of January 8th, 2007, the USS Newport News, a US Navy Fast Attack Nuclear Submarine was sucked into a collision with the Mogamigawa, a supertanker owned by Kawasaki Kisen Kaisha Ltd., a Japanese flagged Very Large Crude Carrier (VLCC) based in Tokyo, Japan. The USS Newport News was operating fully submerged at a routine operating depth for such operations. Both ships were eastbound departing the Straits of Hormuz.
The Straits of Hormuz carry a vast quntity of the worlds oil in a huge number of ships. Traffic is very heavy there. There is a “Traffic Separation Scheme” in place that separates opposing shipping traffic to reduce the possibility of collision in this vital, and narrow, passage.
The USS Newport News and the Mogamigawa were travelling in the same direction so the “Traffic Separation Scheme” did not offer any protection to them. Since the USS Newport News was fully submerged the Mogamigawa was not even aware of her presence and could not take action to avoid the collision.
Why did the USS Newport News not take action to avoid the collision? The answer lies in the contruction of the Mogamigawa. These VLCC ships are huge, in this case 300,000 tons at full load. The Mogamigawa was carrying a full load.
There is so much ship, and crude oil, between the engineroom and propeller, the noisemaking regions of the ship, that anything in a narrow cone in the front of the ship will have no warning of its approach. This shielding effect is pronounced but is a quite narrow cone perhaps 5º and no more than 10º wide.
The next thing to be understood is that these VLCC ships are so large that their draft, the depth of their keel at full load, can be on the order of 120 feet or more. When this is combined with a narrow and shallow seaway, such as the Straits of Hormuz, the stage is set for a collision.
In this case the USS Newport News was certainly operating at what was considered a safe depth for normal operations. The final element of the collision was physics. When two moving bodies operate close to each other a suction is created, the venturri effect. This can then pull a smaller ship into a larger ship.
This same effect causes two ships conducting underway replenisment to have to steer courses a few degrees off what they would in open seas. If one observes two ships engaged in underway replenishment the sea surface between them will actually lower somewhat because of this effect.
The Mogamigawa was on a course nearly coincident with that of the USS Newport News. The Mogamigawa was likely travelling at a speed of 15 to 20 knots. This is a normal speed for VLCC’s in open waters. The USS Newport News must have been travelling less than this in order to be overtaken.
The venturri effect will suck the smaller ship into the larger ship regardless of the speed differential. The only other consideration is that of reduced control response at slow speeds. Any ship responds sluggishly at slow speed and it may be that the USS Newport News was operating at a slow speed with lesser ability to respond to the suction.
In the end the USS Newport News was in a difficult situation, she could not detect the oncoming Mogamigawa and so could not avoid the collision. The United States long ago accepted reponsibility, under the Rules for Avoiding Collisions at Sea, for collisions inherent in submarine operations.
An investigation will reveal whether ships company could have avoided the collision. This in turn will determine the fate of her Commanding Officer, Commander Matthew Weingart.
The Navy has directed a servicewide “Safety Stand Down” in the wake of this collosion whereby all ships, units, and squadrons stop all events and review safety procedures. This type of action is a way for an admiral to seem to be taking action when in fact little changes in the culture that drives accidents.
All these really do is turn down the heat on the admiral.
A “ Safety Stand Down” is a peacetime fiction of today’s military, this nation is at war.
Frequently Commanding Officers are relieved of command in ignominy after a collision or grounding. There are notable, but rare, occasions where this does not happen because the collision was truly unavoidable.
The Submarine Force will look carefully into what cues the sonar party had of contacts and find out if there were things overlooked that should have tipped the crew to the approaching Mogamigawa. The training and qualification of crew members will be scrutinized carefully to see if any crewmen were deficient in preparation for their watchstation.
Investigations are important, less because of potential culpability of crew members, but to refine Submarine Force training and become smarter so that this kind of collision is less likely to recur.
Should Commander Weingart be relieved of command because of this collision, Commanding Officers the world around will again remark, “There but for the grace of God...”
Ellie