US Navy destroyer collision

[Snowpetrel]

Originally Posted by Pelagic

Thanks for the plot Snowpetrel... it does seem quite plausible.
(But again we are guessing
indeed we are..
I took some screenshots of the AIS track of ACX Crystal to help give us a better overview and more accurate SOG and COG

I hadn't noticed that slight course change 068 to 088°T. Exactly 20 degrees, pretty standard as a minimum course change, interesting that 88 degrees in the plot has nearly the same effect on CPA as the 130 degree course change

Not sure what the Time stamps are on the recording, but the public report by Captain states

01:15 AM Target Red 40..... apparently no collision concern)
01:20 AM Target starts moving (Implies stationary before)
Final 10 minutes.... Starts Flashing Lights....
I am also surprised about the ten minutes timeframe before the collision. They would only use five flashes if it was a crossing situation. In this case ten minutes is a long time. They would be unlikely to use it while overtaking unless the target was acting very erratically.

Then emergency turn to Starboard
WHY NO DANGER SIGNAL WITH HORN reported?? as it is much more effective than lights.
Using the horn like this in this scenario while at sea is pretty rare (rightly or wrongly) as it would wake up the entire ship and would be unlikely to be heard by another ships watchkeeper inside a bridge. The light signal alone is much more common. In inshore waters five blasts on yhe horn is more common
Seems that if the Fitz had done nothing, they would have been fine

I occasionally run a ship simulator for training and assessing colregs, radar and arpa use. When it goes wrong its interesting. Often the actions of the students make no sense in a rational way, more like a rabbit caught in the headlamps of a car...

[Dockhead]

Originally Posted by TwoBlocked

. . .Even being by the book (RoR), a stand on vessel may maneuver to avoid a collision when it is apparent the give-way vessel is not taking appropriate action. But if at that moment, the give-way vessel DOES take appropriate action, only to counter the stand-on vessel's actions, is anyone at fault? Perhaps not...

That's the classic problem, which the default turn to starboard is supposed to help solve (in many cases). Fundamental geometry of collision avoidance is:

1. One vessel "holds still" so that the other vessel can formulate and execute a solution. The first vessel standing-on enables the second vessel to know where the first vessel will be. Their maneuvers are "coordinated".

2. Failing that, both vessels making late turns to starboard will in most cases not maneuver into each other. I.e. -- their late and "uncoordinated" maneuvers will not cancel each other out.


The bozo in command of the Porter not only failed to spot the tanker, not only failed to get any crossing data, but he darted off to port.


As to fault -- not all that interesting a question. Of course everyone is at fault. No one should have been in close quarters to begin with. Properly handled, even half way properly handled, Fitzgerald should never have been within a mile of anywhere Crystal's bow could ever have been. With no other vessels involved, with no disadvantage of speed or maneuverability (on the contrary), there is simply no reason for the Fitzgerald to have been there.

Crystal is also at fault. Of course. I have far more sympathy for them, of course, since they were likely (?) the stand-on vessel, and unlike the Fitz, was not receiving AIS data on the other ship -- which would have enormously helped to understand the fast-developing situation. But despite all that, barring something really bizarre, Crystal should have maneuvered earlier. We can just imagine that there was something "really bizarre" --
say, Crystal could not maneuver earlier because Fitz greatly increased speed at the last minute, completely changing the crossing after the time when Crystal could still do something effective to resolve it. But we'll just have to see the complete facts when they come out, to see whether something like that is true.

[estarzinger]

Originally Posted by Pelagic

If the Captain was called, it was probably only 90 seconds before collision.

That is when the OOD should have hit the collision alarm, which he did not do. Really can't be "too busy" to do that - and they train this very frequently - and it is drilled into them this is a critical life saving action (as in fact it would have been).

I still suspect they did not see anything.

I can't explain how that could happen, but it seems (to me) more consistent with the facts we know than anything else.

But I agree there are other sorts of explanations, like the OOD just froze and forgot all his training entirely. (But even then someone else should have hit the collision alarm).

[Pelagic]

Originally Posted by Dockhead

... But despite all that, barring something really bizarre, Crystal should have maneuvered earlier. .

The way I understand it,

Crystal did not consider it a dangerous situation when bearing Red 40° at 3nm. They would have maintained a CPA of over 1.5nm which is acceptable in that Traffic density.

5 minutes later that all changed when Fitz started moving but by then, they were in a close quarter situation.....

I believe that the shared fault lies in both ships failure to communicate their intentions, but if we believe the Captain's report, the Fitz's actions alone guaranteed a collision.

[Dockhead]

Originally Posted by Pelagic

The way I understand it,

Crystal did not consider it a dangerous situation when bearing Red 40° at 3nm. They would have maintained a CPA of over 1.5nm which is acceptable in that Traffic density.

5 minutes later that all changed when Fitz started moving but by then, they were in a close quarter situation.....
The shared fault lies in both ships failure to communicate their intentions.

If that's really what happened, then it seems that there is practically nothing the Crystal could have done to avoid the collision.

So far, we only have a leaked summary of the Crystal captain's internal report, to support that idea. I've said that I wouldn't expect that report to fudge much, considering the VDR and data from the Fitz will eventually come out to confirm or give the lie to what the Crystal captain says.

But, as they say, we shall see . . .

[hpeer]

Over on gCaptain there was some discussion of how Navy officers are trained. It seems to rely a lot on "OJT" on job training. I was interested in the focus they placed on training. Because of the way the advancement structure is junior officers need to get trained (check off boxes) to advance in their career. For some there is not a lot of sea time between shoreside deployments for various reasons.

So imagine on the bridge is the OOD, who may have limited experience himself, training one or two juniors.

I am thinking back to an incident with my Wife. She was bugging me to explain how I was coming off the dock. It was an open face parallel to a strong current. I can do it fine alone, but with her asking me questions I got distracted and let the lines go without anyone aboard. While I recovered it was a near disaster.

[TwoBlocked]

Originally Posted by hpeer

Over on gCaptain there was some discussion discussion of how Navy officers are trained. It seems to rely a lot on "OJT" on job training. I was interested in the focus they placed on training. Because of the way the advancement structure is junior officers need to get trained (check off boxes) to advance in their career. There was some is relatively not a lot of sea time between shoreside deployments.

So on the bridge is the OOD, who may have limited experience himself, training one or two juniors.

I am thinking back to an incident with my Wife. She was bugging me to explaine how I was coming off the dock. It was an open face parallel to a fair current. I can do it fine alone, but with her asking me questions I got distracted and let the lines go without anyone aboard. While I recovered it was a near disaster.

When I got out of the USCG, I sailed for NOAA. If I remember right, shortly after getting my unlimited Able Body Seaman Card (3 year sea time) I was on the helm and realized that I had more sea time, and probably better judgment, than all three officers that were on the bridge put together.

And as I understand it, it is not so much training that is required for advancement as the CO's fitness reports. Of course he is going to favor those that seem pretty much like he is...

[estarzinger]

Originally Posted by hpeer

I am thinking back to an incident with my Wife.

lol . . .yea . . . . there is something about teaching a wife that is . . . . difficult.

[Astrid]

Originally Posted by GordMay

Indeed!
I didn't see "it".

Same here. I missed the gorilla suit guy completely.

[hpeer]

It's called a SELECTIVE ATTENTION test.

What it really means is we suck at multi tasking.

What if the OOD was distracted, his attention was demanded elsewhere. He THINKS he has it together, he is REAUIRED to multi task, but in fact no one is dedicated to watching for traffic. Everyone thinks someone else has it covered and the guy who is running the show is distracted. Wham!

Is that what happened here? Not a clue, could be, maybe not. It would explains how the Fitz didn't see the Crystal.

I'm just trying to show that there are totally different ways of analyzing the problem, not all are technical let alone technological.

[Pizzazz]

I am trying to understand the radar information that a typical modern destroyer has. There seem to be two main surface search radars on this type, the SPS-67, a 260 kW radar and the SPS-73 which appears to be based on a commercial Furuno 25 kW radar. Looking at the specs of these radars, they appear fabulous: smaller than 1 degree beam, gyro stabilized (probably 100 times better stabilization than what we have on our sailboats), automatic ARPA, stable platform, etc. I would assume that even with the smaller radar, you should be able to accurately show the maneuvers of another ship 1-2 nm away.

Assuming the theory that the USS Fitzgerald tried to dash in front of the freighter and the alleged time of the collision of 10 min after the sharp right turn, I totally cannot understand why the Navy ship did not take evasive action. May be it was less than 10 min between the turn and the impact.

So, what is the typical operation of these radars on Navy ships? Is the big (-67) surface search radar usually on or off? I would be surprised if a destroyer only relied on a souped up version of a (small) commercial radar for navigation at night.

[El Pinguino]

Originally Posted by Pizzazz

I am trying to understand the radar information that a typical modern destroyer has....... I would be surprised if a destroyer only relied on a souped up version of a (small) commercial radar for navigation at night.

Why would you need anything more than a 25Kw radar such as the SPS73 for surface navigation and collision avoidance? Its Raytheon not Furuno.... good kit..Raytheon.

SPS-73 RADAR

[Pelagic]

All IMO approved ship sized ARPA Radars have the same weakness....that is the operator!

There is a fine line in settings between detection of small weak targets and overpowering the return.

Many experience operators manually tune and gain, similar to a sonar operator.

However, too much sensitivity so that the ARPA data bounces from bow to bridge of a large ship is a common mistake....that gets dramatically worse as the range decreases, thus giving false info..

In dense cross traffic like approaches to Singapore or HK/Tokyo, you are acquiring targets at 10nm on one display.... Assessing till about 6nm then handing over that named Target to a 2nd Display tuned for lower ranges to be adjusted down as the CPA gets down to often less than a mile.
AIS now makes this easier with an independent verification and intelligence on the target.

But Radar is still needed for small craft without AIS

[Pizzazz]

Originally Posted by El Pinguino

Its Raytheon not Furuno.... good kit..Raytheon.

SPS-73 RADAR

The origin of these radar sets is quite confusing. I found another reference on the web: https://apps.fcc.gov/els/GetAtt.html?id=134170&x=. It says: "The USN AN/SPS-73(V) radar configurations are based on the Furuno Model FR-2120 commercial X Band surface search navigation radar" and there is a picture with a Furuno antenna. My Raymarine radar has a JRC magnetron in it. Go figure.

In any case, the reason I was asking if the SPS-67 radar is typically on is that radar is used to direct gun fire. If it could do that it surely can figure out the bow, the stern and the movement of a commercial ship.

[hpeer]

Well, maybe. Do we have any direct evidence of their profecciency?

IRC the USCG had to sink a Japanese derilict a bit ago. They put a lot of rounds into it and finally sunk it with hand set charges or some such thing. That was in broad daylight and the CG. When was the last time the Navy sank a hostile vessel trying to evade it using a deck gun?