USS Fitzgerald collides with ACX Crystal off coast of Japan


I love ARPA, and there are a number of other useful tools that can be brought to bear.

But I teach my mates to always fall back on a virtually fail-safe basic radar method: a simple line and a ring (even on an unstabilized radar) will seldom let you down. Put an EBL and a VRM ring on a target and watch. If the target moves (exactly or more-or-less, doesn’t matter which) down that line you WILL collide or come very close to doing so unless somebody (either or both) does something to remedy the CBDR situation.

No guessing, no algorithms, no bullshit. And no way to really screw it up accidentally unless you’re just one of those people that can find their way into an accident no matter what. Putting the radar into unstabilized mode eliminates the possibility of a drifting gyro inducing an error. If visibility permits you can and should use your :eyes: to double-check what the radar is telling you, or vice-versa. CBDR is CBDR, no matter how you cut it. You’ve got to do something to resolve it.

Collision Avoidance

The timing of the collision is pretty hard to say using the AIS track.
Around 1630 UTC give or take a minute, Or as you say between 1630 UTC and 1633.
I think other people have concluded, Based on Impact damage and the AIS track the Fitz approximate heading at time of impact was around SE. 135. This appears to be consistent.

Here is the speed and heading info from the ACX AIS track starting approximately 10 minutes prior to the collision.
1619 UTC 18.1 Kn Co 069
1621 UTC 18.4 Kn co 070
1624 UTC 18.4 Kn Co 070
1627 UTC 18.5 Kn Co 070
1630 UTC 17.3 Kn Co 088
1633 UTC 11.2 Kn Co 135

The speed and heading at 1633 the ACX is approximately 90 degrees from her heading of 070. her speed reduced to 11.2 knots.

My guesstimation of the Manoeuvering characteristics of a Container ship of the ACX Crystals size with a single screw direct reversible slow revving diesel.
At 18.5 knots, Rudder Hard to starboard, No engine Movement, approximately 4 minutes later. Heading Changed by about 90 Degrees, Advance approximately 0.5 miles. Speed reduced to 10 or 11 knots. Give or take a Knot, Minute or a Cable.

My guess the ACX version of events so far. Is roughly consistent with the AIS track. Working back from 1633, My guess the Hard to starboard was applied around 1628 UTC or 1629 UTC. Pure speculation of course.

I don’t see any apparent indication from the AIS of telegraph or throttle movement until some time after 1633 UTC

The ACX Applied Hard to starboard, After signaling with the flashing light (probably at least 1 set of 5 short flashes) waiting for a reaction and seeing none.

The ACX Decided to signal the vessel approaching on her port bow. After having become concerned the Vessel she perceived as give way was not taking appropriate action.

The ACX has a vessel approaching on her port bow. Less than 3 miles away, The ACX perceives it is a crossing situation and she is the stand on vessel.

The ACX reports the Fitz as a Crossing Vessel. (Masthead and sidelights visible) approx. 40 deg x 3 miles to Port 10 minutes prior to the collision. Its unlikely this timing is accurate its based on the OOW recollection. Its Unlikely it was logged.
The VDR data from the ACX will show the Radar Picture. If tracked by the ARPA the Data will show the relative and true motion of the Fitz and the timing of any alterations of course and or speed. It will be possible to calculate from raw target data even if the Fitz was not tracked as an acquired target.

The ACX report having used a light to flash at the Fitz. When probably prior to ordering hard to starboard, How long before?
Using an ALDIS light to Flash 5 Short and rapids. I have done this.
Radio, Who was he going to Call, “Ship My Port Bow” He didn’t its an omission. Would It have done any good? Not the point. Wasn’t done.

The ACX identifies the Fitz as a crossing vessel. Presumably The ACX could see Masthead and side lights. There is no mention of stern light by the ACX. This does not mean it was always a crossing situation. Or not just the ACX considered it a crossing situation.

So the ACX stood on maintaining her course and speed. With a vessel approaching quickly from a distance of less than 3 miles away on her port side.

A container ship this size stopping distance? crash stop ball park 1.5 miles give or take a bit.
Turning circle 0.5 miles give or take a bit.

This is all happening pretty close to acceptable minimums.

The ACX reports 3 people on bridge in hand steering, Was this Capt., OOW and QM or OOW, QM and Lookout.

The ACX makes a routine course alteration which may have contributed to a close quarter situation developing.

After this alteration.

They see the ship to Port, They see it change course and speed, It takes them a while to figure out its now on a collision course, They wait around for it to react, It takes them a while to get concerned, Then their reaction going hard to starboard is very late and the approaching ship is very close.

To little to late.


Jeez you must be old. Unstabilised? Tow boater?

Even older than me, Heads up , Unstabilised, A mechanical cursor and a range ring, WTF it works, doesn’t it.

I must be just a bit younger than yourself. I like. N up, relative, stabilised, (No targets getting spread by yaw)
Many years using a china pencil a mechanical curser and a range ring.

I don’t like these new fangled true motion gizmos. Young guys nowadays.

True motion does have its advantages, But I am to old to really like or trust it.

  1. Seven years enlisted in the USN. Commissioned as Ensign. On my first ship. JOOW on the bridge. Learned to do initial contact CPA on the SPA-25 radar display, using a china pencil and tongue depressor as straightedge. Hard during the day with the big hood on. If within certain parameters, transferred the work to a MoBoard. CIC also plotting and sending solution up to the bridge, so comparison made as check.

Want to know the all important bearing drift. Get out on the bridge wing and start checking with an Alidade on the gyro repeater. And remember, just because you have good bearing drift on his deckhouse doesn’t mean you’re going to clear the other end… :slight_smile:


At this point there is so little information, Anything I say is little more than a wild guess. Somebody told me a long time ago. "Never said the guy who knows what happened to investigate an accident"
Sometimes its hard to keep an open mind, But you have to.
Usually if think I know. It often turns out to be something quite different. Sometimes completely new.
I don’t know anything about how the Navy operates just speculated based on how some BRM stuff from the commercial world. On the assumption people are just people. regardless of organisation.

There is no way of knowing if it was ever an overtaking situation or always a crossing situation.
The ACX did make an alteration, of almost 20 degrees, large enough to be significant perhaps not quite large enough to be readily apparent. I was just contemplating the possibility this change may not have been “seen”.
I will google Jal Flt 2,
I watch a lot of “Mayday” TV Shows.


Yes, I’m a wire-boat guy and I even pulled hawser back in the day. But that isn’t really relevant.

I’m not suggesting that there’s anything wrong with using north-up or stabilized radar, or anything else, for that matter. There’s a time and place for everything, if used in the right manner in the right circumstances.

But if you want a tried and true way to quickly determine risk-of-collision that essentially can’t lead you astray, temporarily switching to head-up/unstabilized display eliminates virtually all possible ways that you could be fed bad information that would skew how you choose your possible solutions. Gyros are generally very stable and reliable, but they can drift. Going to unstabilized eliminates that as possibility. As long as the heading flash is on or within about a degree of 000 deg. relative on your centerline then WYSIWYG on the radar display. It won’t lie to you. CBDR with this set-up is unmistakable.

That can save you in a bad spot, particularly in restricted visibility. If you find yourself getting into trouble or start to feel yourself losing your overall situational awareness it’s a great way to re-set and start over in a pinch.

One of the most important things I was taught to avoid when I went to ARPA training back at the old SCI in Manhattan was the ARPA-assisted collision. This was reinforced in the simulator by, you guessed it, the instructor inducing a small and gradual drift into the gyro. The display showed no problem, but the view out the windows told a different story. The lesson: if there’s a discrepancy between what the display shows and what your eyes are telling you then you go with the latter. Don’t screw around, act decisively.

It’s way too easy to blindly trust the black boxes, even when they’re obviously lying to you. Much more dangerously, when they just fib a little, or inconsistently. Youngsters of the Information/Digital Age, especially, are prone to this, but no one is completely immune. It takes discipline to consistently cross check.

But the Reagan Doctrine is always appropriate: “Trust but verify.”


This is worth emphasizing!


Yes, very much so. And thank you for doing it.

You kind of need to see RR delivering the line. There’s a bit of a wink-wink element to it that doesn’t really quite ever translate into this medium the same way as the spoken word does when you’re watching the speaker.

I guess I could have gone with “Trust (:stuck_out_tongue_winking_eye: or :joy:) but verify!”


I think you’ve pretty much covered all of the bases…

I understand the AIS data shows both course (velocity vector of the AIS transponder) and heading (orientation of the bow of the ship). I understand that the heading at 16:30 was 112 degrees, even though the course was only 88 degrees, i.e. the ship really was turning hard to starboard, i.e. off original track and getting more so. Already by 16:33, the heading was “inside” (to the north) of the course, i.e. the ship was already returning to its original track.

So I think that your speculation of a turn initiated around 16:29… detectable in the AIS data at 16:30… is warranted. I’d offer that:

16:29 = turn initiated
16:30 = AIS ping
16:31 = collision

~2 minutes @ ~18 knots = 0.6nm = 1200 yards… a hundred seconds would be a thousand yards…

So I’d offer that evasive maneuvers were undertaken at a range of a thousand yards or so… is that reasonable?

It seems remotely possible that the warship was heading due east for several hours, paralleling the merchantman… and that the former simply kept going straight east into the collision, after the latter turned NE approximately 10-15 minutes prior to impact… Perhaps the Crystal really was on auto-pilot and simply drove into the warship at a relative angle of 20 degrees? But, if so, I cannot myself imagine how such a grazing impact would spin the merchant vessel to its port, by over 100 degrees – if you connect the AIS data points, with a spline curve, in Microsoft Powerpoint or the Grapholite app, such that you match the curve to both the positions and course headings, then you find that the only way to connect the 16:30-16:33 data points is with a smooth curve which arcs almost due south for some distance between the 16:30-16:33 locations…

You can eyeball that of course also…

So “70 in, 170 out” would be about a 100 degree deflection, for a 40Kton freighter impacting a vessel a quarter of its size… unless the impact spun the ship and/or the autopilot was confused or something, I really cannot see how such a sharp turn is more consistent with autopilot than human intervention as per the Crystal’s crew’s statements.

So I agree that “the ACX version of events is consistent with the AIS track”, i.e. they were awake & manning the bridge, and did intervene to steer hard astarboard, perhaps at a range of 1000 yards or four ship lengths…

And if you accept that, then you have to conclude that the warship really did indeed make a turn maneuver “10 minutes” prior to impact…

Which, given the earlier easterly heading, puts the warship on something around a 135 heading SE…

and you have BOTH vessels turning towards each other approximately 10-15 minutes beforehand

wish there was more info out there to consider


“I understand the AIS data shows both course (velocity vector of the AIS transponder) and heading (orientation of the bow of the ship). I understand that the heading at 16:30 was 112 degrees, even though the course was only 88 degrees, i.e. the ship really was turning hard to starboard, i.e. off original track and getting more so. Already by 16:33, the heading was “inside” (to the north) of the course, i.e. the ship was already returning to its original track.”

The AIS data is just a series of snapshots joined together by software. The interpolated ‘join the dots’ trace is what Marine Traffics algorithms stitch together. The orientation of the trace is an approximation of the vessels track over the intervening period. It is not the vessels heading. Also, as there is a lag between the AIS ping and the effect of any helm input trying to analyse on a minute by minute basis if futile.

The Japanese CG will have both the VDR from the Crystal, the angle of impact will be evidential from the damage to the Fitz. They will also have access to coastal radar and will be best placed to produce a clear and unbiased report IMHO.


I agree. I believe that the Japanese investigation report is likely to be the only unbiased report we will see in public.


I think you are correct, and until the Freedom of Information Act requests are filled, the Japanese investigation will be the final word.

In the meantime, I believe the Navy will look like incompetent fools trying to hide its incompetence and eventually the FOIA results will echo the USS Porter debacle.


Even if both the US Navy, USCG and the Philippine investigation report is eventually made public, are they likely to be totally unbiased and factual only?

The Japanese has no “national pride” or “coloured glasses” here, as they are the territorial state and, unless there are any reason to believe that their “voluntary TSS” has been a factor, they have nothing to hide or reputation to protect .


Here, I often read about the weight relation containership<>destroyer.
This is a sort of static model, nearly applicable on a billiard table, where one ball transfers its energy to the other one. In a perfectly centered contact, the moving ball stops and the standing ball accelerates to the former speed and direction of the other one.

Her we are in a more dynamic model, in a perfect T-crash the energy of the containership would push the destroyer sidewise away… but the destroyer cannot move sidewise, there are millions of tons of water blocking this movement.

The energy of the containership must transform otherwise. In the first second, the energy is transformed into heat by plying or cutting the hull of the destroyer. Only if the destroyer survives this attack, she would have enough own energy to move the blocking water away by bow and stern or under the hull.

In realty, a perfect T-crash is unlikely, the centers of gravity and of the sideways vertical water surface are not at the same place, unless maybe on an empty barge. Here it seems, the impact was not at 90°.

Then, the first transformation of energy would be the deformation of the hull of the destroyer, and after that, the remaining energy transforms to a forward/backward movement of the destroyer and a turning movement of the containership. Only then, the water off the opposed side of the destroyer could move.

AIS intervals of three minutes may explain the movements into the crash, but never, ever they could explain the ship’s movements only seconds after the crash; AIS was not invented to do this.

I hope that the VDR recordings of the containership may explain a lot…


Going by this information the Fitzgerald was not moving (“5 minutes later the destroyer suddenly starting moving”), the Crystal, with two crew in the wheelhouse put it in hand steering, turn some light off and on (maybe deck lights or Aldis as discussed) and when there was no reaction the Crystal made a hard turn to stbd.

If that’s the case the Fitzgerald may have been increasing speed before the collision while the Crystal was in a hard right turn,


I look forward to the info from the VDR, and only hope we get good info from the FITZ side.

The ACX Crystal captain indicates that the Fitz was sighted 40 degree to port at 3nm around 0115. This is about the same time that they altered course to port by approx 20 degrees, from due East to East by Northeast. So, was the Fitz 40 degrees to port before the Crystal turned towards her, or after the turn?

No aspect, or target angle, is given for the Fitz. IF Fitz was 40 degree to port at 3nm before the Crystal turned, AND if the Fitz was also on an East heading, then Crystal was well abaft the Fitz’s beam, would have only seen her stern light, and was an overtaking vessel.

As I have noted previously, I don’t know what happened on either bridge, but as a retired naval officer and surface ship driver, I still can’t grasp how the Fitz got hit, seemingly without warning (i.e. internal).


This is a translation of an article which may have been written in Japanese by a non-mariner, based on his understanding of a preliminary report by the Master of Crystal. (Reuters also have a Japanese division)
The Master may or may not have reached the bridge until a short time before the collision and his statement being based on what his 2nd Mate told him about the events leading up to the collision.

IOW Plenty of room for inaccuracy and misinterpretations here.


In either case, range and bearing before or after the turn, the watch officer would likely have been under written instructions to maintain a minimum CPA, or if not able, call the captain.

Also not many shore lights there to speak of, the fishing vessels tend to be inside or closer to the entrance to the bays. I would not expect concentration of fishing vessels in that area.


"Under strict orders not to talk about what they saw that night, the crew of the Fitzgerald is mostly keeping its counsel while grieving the loss of its shipmates. But one sailor, contacted via social media, offered what may endure as an epitaph for the accident.

“All I can say is,” the sailor wrote to The New York Times, “somebody wasn’t paying attention.”



I disagree, shipmate. I heard comments like that a lot in the Navy. You say you have silver dolphins, so I’m sure you’ve heard people say things like “its dangerous down here”, “the sea is a harsh mistress”, “the sea is a [female dog]”, etc.

Captain James Baumstark, USN (Ret.), former Captain of USS Michigan SSGN-727 (at the time, SSBN) said the following on a TV documentary special:

Source is this youtube video here , starting at two minutes and fifteen seconds in the video.