Collisions of USS Fitzgerald and USS John S. McCain

Reminds me of a similar incident between HMS Southampton and a tanker in the Persian Gulf in the 80's.

Always sad to read of a loss of life.
 
The missing sailors are reported to have been inside the flooded compartments below decks. Does that mean the bulbous bow of the container ship had pierced the hull of the USS Fitzgerald? If she could not withstand that kind of impact it really shows what the Titanic was up against when she struck the iceberg. RIP to the victims.


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A few years ago here at Belfast lough the captain of a cargo ship got drunk and went in circles about 10 times before crashing into a Stena passenger ferry. The captain was sent to prison for a year. Collisions at sea must be a rare occurrence these days but they certainly show the energy involved when two vessels collide.


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The photos show the USS Fitzgerald was struck on its starboard beam by the bow of the ACX Crystal. This could have been a simple crossing situation, at right angles? If so, my ancient understanding of the rules of the road would have made the Fitzgerald "burdened," in which case it would have been responsible to maneuver to avoid a collision, while the Crystal would have been obliged to maintain course and speed. But, a report on Japanese public broadcasting claimed that the Crystal made a sharp turn just before the collision. We'll have to await the ensuing investigation. The collision occurred at night after the captain had retired.

But, this raises a question in my mind. Many decades ago, navy ships manually plotted on paper courses of other ships in the vicinity, using radar ranges and bearings, and continuously calculated the time, range, and bearing of the predicted closest point of approach. The OOD and the bridge watch would keep an an eye on other ships with a close CPA, visually check their side and range lights, check the bridge radar, check bearings with the pelorus to make sure they were drifting away nicely, and make sure that updated CPAs were passed along to the bridge from the plotting below. Do I understand that this is now all done automatically by computers?

The commanding officer would leave instructions in the night order book specifying the circumstances when he must be awakened and summoned to the bridge. One such situation would be if the CPA of another ship is computed to be less than a specified distance.
 
Doug -- "burdened" and "privileged" were dropped from the law in latter days in favor of "give way" and "stand on," but nothing really changed. The problem was that smarmy sea lawyers were slowly twisting the intent of the law. Some cases held that the "privileged" vessel lost some or all of its privileges if it maneuvered to "take a glancing blow" when in extremis. By changing the wording all of that lubberly case law was thrown out the window and we got back to seamanlike regulations.


Under the Rules there are only three ways in which ships can approach one another so as to involve risk of collision: 1.) overtaking; 2.) meeting (head on); and, 3.) crossing. The damage rules out the first, overtaking. Of the remaining two, in a meeting situation neither vessel has right of way. Both are to turn to starboard and pass port-to-port unless some other passing has been agreed upon in advance (by using whistle signals). From the damage, the two ships could not have been in a meeting situation unless one or both turned to starboard for some unexpected reason.

We are then left with a crossing situation. This is usually depicted as a right angles cross, but in reality the angles are inconsequential. If the vessels are approaching one another in such a way that it is neither a meeting or overtaking situation, then it is a crossing and the vessel with the other on its starboard side must give way to the one with the other vessel on its port side.

Note that a starboard light is green ("go") and a starboard light is red ("stop"). The Navy vessel would have been showing its green while the cargo ship would have been showing its red sidelight.

If the give way vessel does not appear to be taking appropriate action, the stand on vessel may take action to avoid a close quarters situation. However, if the situation deteriorates to extremis (one in which a collision can not be avoided by actions of the give way vessel alone) the stand on vessel may take whatever action necessary to take a glancing blow or reduce the inevitable damage. It may not, however, turn to port for a vessel on its port side.

We don't know exactly what happened. It does appear the Navy ship was the give way vessel and, for whatever reason, did not give way. The stand on vessel, the container ship, waited to extremis and turned to its port in order to take that glancing blow. If what we see in the damage turns out to be true, the U.S. Navy captain may want to apply to Uber to drive a cab. He won't be seeing the bridge of a ship again for a very long, long time.

-- David G. Brown
 
Here is the track history of the ACX Crystal from the day of the collision. Any ideas what they were doing? It appears they changed course and were turning back when the collision occurred.






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Doug Criner said:
But, this raises a question in my mind. Many decades ago, navy ships manually plotted on paper courses of other ships in the vicinity, using radar ranges and bearings, and continuously calculated the time, range, and bearing of the predicted closest point of approach. The OOD and the bridge watch would keep an an eye on other ships with a close CPA, visually check their side and range lights, check the bridge radar, check bearings with the pelorus to make sure they were drifting away nicely, and make sure that updated CPAs were passed along to the bridge from the plotting below. Do I understand that this is now all done automatically by computers?

The commanding officer would leave instructions in the night order book specifying the circumstances when he must be awakened and summoned to the bridge. One such situation would be if the CPA of another ship is computed to be less than a specified distance.
Click to expand...

Hi Doug.

I last set foot on the bridge of an RN warship in January 2013 so I'm relatively up to date. In the RN, it's not too far off as you describe in your post however you are correct that automation has taken over in many areas.

The Captains night order book as you say, contains his policy for navigating the ship overnight. When he is to be called etc. On taking over each watch, the Officer of the Watch will call down to the plot position in the operations room and state his radar policy for the watch. This will include at what range he would like the radar to sweep out to, what range he would like contacts reported from and at what CPA. That will generally be in line with the Captains night orders.

An RN warship has two Nav radars. One will be linked to the ships main operations system (targets can be displayed on any radar screen, on the bridge relay screen and on the electronic chart system) and a second one that is a stand alone unit and located on the bridge (though that unit can also feed into the electronic chart display). The officer of the watch can configure the stand alone radar to alarm against contacts that will approach within a defined CPA. The CPA's on the main and secondary systems are electronically calculated.

Generally speaking, in clear visibility and in open ocean, the operations room 'plot' position may be stood down and the OOW may deal with the ships navigation entirely from the bridge. Most of the time however, the operations room reports all contacts to the bridge and the OOW will check it against the various other systems then, if required, call the captain.

Finally, there are still two or three pairs of Mark 1 eyeballs available to back up the radar and other navaids.

Hope that helps.

Regards

Rob.
 
Like most reports, this one was obviously written by someone unfamiliar with the fact that weight and tonnage can't necessarily be compared. In particular, you cannot compare military ships with civilian cargo vessels by their tonnages. Apples to cumquats, so to speak.

Military tonnage is displacement which is the weight of water in the "hole" in the ocean created by the ship. Civilian tonnage is "Admeasurement" and does not measure weight, but rather cargo carrying capacity in cubic feet. Simplified admeasurement says 100 cu feet equals 1 ton. In big ships, this is modifed and bent around by the naval architects, etc., but Admeasurement always measures cubic volume and not the weight of water displaced.

This is why military ships often look puny compared to large cargo vessels. Different long splices for different ships -- and different ways of measuring.

-- David G. Brown
 
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