USS Fitzgerald collides with ACX Crystal off coast of Japan


#568

AIS is a source of navigational information and can assist in tracking a target (position updates are in-frequent, depending on speed and rate of turn).
Now, if a Navy vessel is operating stealth (no AIS, no lights and virtually no radar signature) then it is that Navy vessel’s sole responsibility to avoid other vessels in the area.


#569

Let’s get the facts straight.

  1. It is the Fitz starboard deck house on top of a long superstructure say 8 meters above waterline that is damaged by a contact by the Crystal port focsle bulwark say 10 meters or more away from the centreline.
  2. Crystal struck Fitz at about 45° angle.
  3. The Crystal bulbous bow is then always far away from the Fitz underwater hull side (inboard slooping) and will not touch anything.
  4. Fitz main deck and hull side down to the waterline are undamaged.
  5. The only ‘evidence’ of any Fitz underwater damages is a photo showing a square (!) hole in the plate with some external beams fitted.

As far as I am concerned a ship (Crystal) striking another ship (Fitz) in a collision do not rip open a square hole in the underwater shell plate.

It is quite easy to permanently repair hull damages. Just crop away and replace the damaged frames/stiffeners/internal bulkhead and hull plates. I have done such repairs many times.


#570


#571

Negative. No action or lack of action by another vessel will completely remove another vessel’s responsibility to avoid a collision. Otherwise, large vessels could cruise with impunity and not worry about running down some poor sap trying to fish. There are multitudes of fishing vessels the world over with a much smaller radar cross-section than a destroyer and unfortunately many operate with no lights. None of that will remove from an officer in charge of a navigation watch responsibility to avoid a collision.


#572

Oh for Christ sake you are thick. You are making a big deal out of the shape of the patch, yet you basically state the reason the patch isn’t oval shaped.

Just as with permenant repairs it’s a hell of a lot easier to make a temporary patch that’s square than with lots of curves.


#573

I have yet to see any of the actual investigating bodies state as fact the angle of attack so to speak at the time of the collision. While your statement on item 2 seems reasonable, it’s not confirmed as a fact yet is it?

Is the square hole from damage or based on the temporary repairs you saw in photo’s?


#574

The photo is not of the damage.

The photo is of a square hole cropped in the hull plate with some external beams added. The top of the hole is in the waterline.

The Crystal bulbous bow was probably >5 m below waterline and could not possibly have touched Fitz in the waterline.

It would be nice to see a photo of the alleged damages before you start cropping damaged structure.

When I do steel hull repairs I use some scaffolding to work from, so that I can inspect preparatory works before final welding takes place, etc, etc.


#575

I’m sure the Navy will be right on top of that request. I would hope the divers took a few before making a temporary patch to stabilize things so they could get it in a dry-dock. One might actually see them if and when the Navy completes and releases any investigation to the public.

So we can agree it’s probably not a fact that the initial hole was actually not square?


#576

Here’s a photo (source) of ACX Crystal’s bulbous bow. There’s surprisingly little damage, indicating that the appendage was not pushed very deep into the hull of USS Fitzgerald.

Heiwa, it does not matter where the container ship’s forecastle came in contact with the destroyer’s superstructure when there’s a clear mark at the main deck level indicating the lowest above-waterline point of contact between the two vessels - a mark left by the stem and v-shaped frames. As per photographs posted earlier, ACX Crystal’s bulbous bow is easily long enough to “touch” the Fitzgerald’s shell plating even if the latter is sloping inwards below the deck edge.


#577

I said Navy vessels, not commercial or other vessels. When a Navy vessel is invisible, slammed to the hilt with electronics and watchstanders, it’s obvious that they should avoid vessels that can’t see them.


#578

I’d say the bulbous bow penetrated to about where the marine growth stops…

But then again neither of created a tanker design not used the world over.


#579

That still does not remove the responsibility of the officer in charge of a navigation watch on any vessel to avoid a collision. There will be plenty going back and forth with who is more at fault and to what degree, but it does not remove it entirely.

Yes, it’s obvious Naval vessels should not allow container ships to run them down.


#580

I’m inclined to agree. There may be some plastic deformation in the plating that is not visible in the photograph. I’m quite sure we’ll see more in the coming days.


#581

Well, the top of the hole cropped in the Fitz’ side is in the waterline, while the top of the Crystal’s bulbous bow is several meters below the waterline.

The Crystal’s bulbous bow cannot damage the Fitz side in the waterline! It is several meters away from the Fitz’ side several meters below waterline.

The contact was at the Fitz’ deckhouse >8 m above the waterline. The Fitz’ superstructure and hull side down to the waterline are then undamaged.

Let’s await pictures of alleged underwater damages before cropping.

BTW I doubt divers did any cropping or temporary repairs under water.

Normal procedure is to drydock the ship and then fit scaffolding for close up inspections, etc.


#582

Alleged? Wow, interesting choice of words.

They just did the initial inspection and probably put that patch on to make it easier to drydock the ship, hence the term ‘stabilize’. You know, close up the ‘alleged’ hole so the flooded spaces could be dewatered.


#583

When looking at the draught marks, I’d say the top of the bulbous bow was about 1 m (3 ft) below waterline in the photographs taken on the day following the collision. I doubt there has been any significant change in the loading condition (ballasting or de-ballasting) following the incident; if anything, there might be some flooding in the bow compartments if the shell was ruptured, submerging the bulbous bow further. Also, the kind of bulbous bow fitted to ACX Crystal needs to be close to waterline in order to function as intended.

That is correct and in line with what can be observed from ACX Crystal’s damage. The contact point above waterline was at the inclined part of the container ship’s stem, meaning that the vertical part of the stem did not come in contact with the destroyer’s hull.


#584

Check out the photo at post 264 for water line at time of incident. It all adds up to your line of analysis (and what I was trying to say back then). But to save yourself getting heartburn you should resist engaging with this guy.

Also on the drydock photo there is some fresh rust on the varicose vein above the hull damage and on the de-ballasted photo some more scratch marks on the vertical stem above the bulb which also lines up with what you are saying about the points of contact / structure shapes in this area.


#585

Hm, sending down divers to crop a square hole in the side that then can be patched up by welded steel plates underwater to enable drydocking doesn’t sound right.

The cropped hole is 3-4 meters long and if it is in way of a bulkhead two watertight compartments are up-flooded. If it is between bulkheads only one watertight compartment is up-flooded. In either case no big deal.

There has been reports of three watertight compartments flooded but it is only possible when watertight doors are kept open.

M/S Costa Concordia capsized and sank on some rocks after a small hull contact, when crew opened (illegal) watertight doors after the incident during abandon ship, which caused progressive flooding of intact compartments, loss of buoyancy and stability and capsize. I describe it at http://heiwaco.com/news8.htm . The wreck was removed from the rocks and brought to a port to be scrapped in drydock. But it was not possible! Instead they patched up the hole in the side so the wreck could float, and towed it out to sea … and sank it … again. I describe it at http://heiwaco.com/news811.htm .

Maybe the best solution for the Fitz? Just tow her out to sea and sink her?


#586

I knew I should’ve read the thread through before posting - now I’ve been more or less repeating things you guys discussed weeks ago.


#587

[quote=“Heiwa, post:585, topic:45129”]
Hm, sending down divers to crop a square hole in the side that then can be patched up by welded steel plates underwater to enable drydocking doesn’t sound right.
[/quote] Good thing they listened to professionals who might do something weird like analyze the situation and come up with a good plan so the ship could get in the drydock instead of saying, that “doesn’t sound right” and giving up.

[quote=“Heiwa, post:585, topic:45129”]
In either case no big deal.
[/quote] Except for the fact that seven people are now dead.

[quote=“Heiwa, post:585, topic:45129”]
There has been reports of three watertight compartments flooded but it is only possible when watertight doors are kept open.
[/quote] Depending on the extent of the damage.

Your way out there on this one, among other things. You really think Schettino should not be in jail and prevented from ever sailing again? Sorry, not sorry.