Collision Avoidance

[requiem]

Originally Posted by skipperpete

Good point, almost none of them were transmitting AIS data at the time of the collisions and the more recent were not particularly visible if at all on radar.

ACX Crystal had a bit of clutter compared to one of the other ships at the scene, but even with the filtering on the Wan Hai 266's screen, Fitzgerald was showing up.

[Lodesman]

Originally Posted by requiem

Is there a TSS (voluntary or otherwise) here? I thought I remembered one as well, but don't see any mention in the report. A peek at TSS in the area suggests I'm remembering the one off Iro Zaki (further East) but don't recall which particular collision it featured in.

From the various diagrams in the NTSB report, it appear the three eastbound ships all made similar turns to port. It mentions the Crystal's turn as part of the voyage plan, and such turns would be expected for those ships to avoid the islands of Toshima and Udone-shima.

This was in one of the previous threads, from one of the media reports. Voluntary TSS afaik. Crystal was in a crossing with Maersk Evora, and did the unwise turn to port (at 0115 or 0119?)- which then put her on course converging with Wan Mai, and collision course with Fitzgerald.

[TeddyDiver]

Originally Posted by Lodesman

snip..
At the point that Crystal turned to starboard, Colregs does not "suggest" a turn to starboard - but Rule 17(b) says to take whatever action as will best aid to avoid collision." A turn to port would have been better, but I don't blame them on that point - it would have been pretty difficult to decide the optimum solution then - hindsight is 20/20. There are threads on this topic, if you want to read more on it.

Rule 17(c) says clearly ".., not alter course to port for a vessel on her own port side."

[wholybee]

Originally Posted by TeddyDiver

Rule 17(c) says clearly ".., not alter course to port for a vessel on her own port side."

And there is a very good reason for that. If a stand on vessel feels the give way vessel (on the port side) is not taking action, and the stand on vessel turns to port, and at the same time the give way vessels turns starboard to go aft of the stand on vessel, those 2 actions together create a head on collision.

Whatever action a stand on vessel takes needs to consider possible actions the give way vessel will also take.

[Lodesman]

Originally Posted by TeddyDiver

Rule 17(c) says clearly ".., not alter course to port for a vessel on her own port side."

It clearly says that when taking "action in a crossing situation in accordance with subparagraph (a)(ii) of this Rule." 35 seconds before the crunch, I think that Rule 17(b) applies more so than (a)(ii).

[TeddyDiver]

Originally Posted by Lodesman

It clearly says that when taking "action in a crossing situation in accordance with subparagraph (a)(ii) of this Rule." 35 seconds before the crunch, I think that Rule 17(b) applies more so than (a)(ii).

Not to port! Not without common understanding. Fizgeralds left rudder was idiotic maneuver in this situation Remember, it was not just a crossing situation but last chance to avoid collision.

[requiem]

Originally Posted by Lodesman

This was in one of the previous threads, from one of the media reports. Voluntary TSS afaik. Crystal was in a crossing with Maersk Evora, and did the unwise turn to port (at 0115 or 0119?)- which then put her on course converging with Wan Mai, and collision course with Fitzgerald.

Ok, I'm a bit better oriented now; I was placing the collision one headland to the west. Yes, this was indeed the one off Iro Saki with a TSS, note closely the TSS' position relative to the land and Mikomoto Shima



The early tracks though look more like the screenshot below. In the media report image, the TSS is placed very incorrectly. Notice also how the initial position of the Crystal in that diagram is very close to the island Mikomoto Shima, which provides the reference point for the bend in the TSS.

[skipperpete]

Originally Posted by Lodesman

Sorry I don't meet your strict requirements for entering a discussion, and didn't flip through half a dozen accident reports to positively identify the specific incident to discuss an inconsequential tangent to a tangent to the original topic.
Sorry for assuming the average person would get from "in one of those collisions" that if it wasn't one, it was the other.
The vessel "opposite" Fitzgerald obviously wouldn't be Fitzgerald - are you being deliberately obtuse?
So to meet your requirements, I've gone back and quickly had a review of the NTSB report. I couldn't find "inexplicably" written anywhere in the report - did you make that up?
It is, like most of these reports, somewhat lacking. No-one disputes that Fitzgerald made a bunch of mistakes, but Crystal also did. You should read the other reports. When they were 6.5 miles apart, Crystal turned to port, putting them into a collision course with Fitz. Had Crystal not made that turn, she would have passed nearly 2 miles ahead of Fitz. Fitz had been painting on Crystal's radar from 13 miles away. The NTSB describes Crystal's original course as "easterly", but other reports show they were ESEly, cutting the wrong way through the voluntary TSS lane and separation zone, before altering to 069º (breaking rules 10 and 17). In fact they also kinda fractured Rule 15, as they were give-way to a Maersk vessel closing from their starboard side prior to that turn. The second officer on the Crystal apparently didn't see Fitz's navlights until about 3 miles away. Despite the fact that other vessels had seen Fitz's steaming light, Crystal apparently only saw a green running light, and made the assumption (strangely) that that indicated a fishing vessel. If it was a fishing vessel, (or a sailing vessel, as that would be what a lone green light would actually indicate) Crystal should have given way (breaking Rule 18), but instead they chose to shine their aldis lamp in that direction. At the point that Crystal turned to starboard, Colregs does not "suggest" a turn to starboard - but Rule 17(b) says to take whatever action as will best aid to avoid collision." A turn to port would have been better, but I don't blame them on that point - it would have been pretty difficult to decide the optimum solution then - hindsight is 20/20. There are threads on this topic, if you want to read more on it.

Lodesman , I’m thankful you read the report, this thread is totally and only about collision avoidance and any historical record that helps us to understand how NOT to have a collision is useful to the forum members. Most of what you imply in your above post is either wrong or distorted but I’m not going to engage in the ruination of a really useful Colregs thread because of that, the NTSB report and associated images of tracks, plots and shipping lanes makes the circumstances of the incident abundantly clear and a later report mentions a financial settlement by ACX Crystal of $24-26 million dollars and a repair bill for the USS Fitzgerald of over 250 million, not to mention the tragic loss of 7 lives…. No one came out of this unscathed, not the bridge crew on Crystal, not the 6 bridge crew on theUSS Fitzgerald and certainly not the families of those whose lives were lost in the collision.

[Lodesman]

Originally Posted by TeddyDiver

Not to port! Not without common understanding. Fizgeralds left rudder was idiotic maneuver in this situation Remember, it was not just a crossing situation but last chance to avoid collision.

You understand by that point the chance to achieve "common understanding" has long since been lost? At this point, it's about doing the least amount of damage. I'll refer you to the advice you'll find in Cockcroft and Lameijer's Guide to the Rules:

[Lodesman]

Originally Posted by skipperpete

Most of what you imply in your above post is either wrong or distorted but I’m not going to engage in the ruination of a really useful Colregs thread because of that, the NTSB report and associated images of tracks, plots and shipping lanes makes the circumstances of the incident abundantly clear and a later report mentions a financial settlement by ACX Crystal of $24-26 million dollars...

You made such big deal about this, but now you don't want to drift the thread?
How convenient for you - you can just claim my view is wrong or distorted, but offer no "correction."

If the Crystal was entirely blameless, then why do you suppose they paid the US Navy $27 million?

I don't want to bad-mouth the NTSB - they have their purpose, but like most of these organizations, they rarely produce comprehensive reports. Heck, it's a little off-putting when they can't even get the date right.

[TeddyDiver]

Originally Posted by Lodesman

You understand by that point the chance to achieve "common understanding" has long since been lost? At this point, it's about doing the least amount of damage. I'll refer you to the advice you'll find in Cockcroft and Lameijer's Guide to the Rules:

And without any sense (nor common understanding) Fitz turned to port which made them even more vulnerable and was most likely the reason for lost lives.

[Lodesman]

Originally Posted by requiem

The early tracks though look more like the screenshot below. In the media report image, the TSS is placed very incorrectly. Notice also how the initial position of the Crystal in that diagram is very close to the island Mikomoto Shima, which provides the reference point for the bend in the TSS.

Good eye. It does look like a crappy representation of the lanes. I was going from memory of the discussion. This is one of my concerns with the TSB report, is that it didn't discuss this TSS. It's hard to tell from the AIS grab, where Crystal was in relation to it, but it does look like she would have been going the wrong way in the Westbound lane, or fairly close to it. And her left turn was well past being South of Mikomoto Shima, which indicates the bend in the TSS.
Somewhere in the other thread there are a series of radar shots, that came from one of the reports - these clearly show that Crystal was converging with Wan Hai, not running parallel, or turning in unison.

Wasn't intending on getting into a big discussion of something that happened nearly 7 years ago, but I do appreciate your thoughtful analysis, and respectful dialogue. Maybe some others could take notes on how to show someone where they're mistaken without being insulting.

[Lodesman]

Originally Posted by TeddyDiver

And without any sense (nor common understanding) Fitz turned to port which made them even more vulnerable and was most likely the reason for lost lives.

Fitz was the give-way vessel. We were talking about the actions of the stand-on vessel - y'know Rule 17.

The compounded errors on Fitz's bridge were a lot more complex than you suggest. Had there been a proper appraisal done of the developing anti-collision situation, a turn to port might have been the best way out for Fitz - well before they got that close. As I recall there was a rather lengthy delay between the OOD giving the order to come left and speed up, and the Conning Officer and/or Helmsperson actually doing it. Two minutes earlier could have made it a near miss instead.

[Uricanejack]

Originally Posted by thinwater

Obviously, if we follow COLREGS there should be no close calls. Setting that aside, ships do get too close and they do collide, for a variety of reasons.


Rule 17 says:
(a) (i) Where one of two vessels is to keep out of the way, the other shall keep her course and speed.
(ii) The latter vessel may, however, take action to avoid collision by her maneuver alone, as soon as it becomes apparent to her that the vessel required to keep out of the way is not taking appropriate action in compliance with these Rules.
(b) When, from any cause, the vessel required to keep her course and speed finds herself so close that collision cannot be avoided by the action of the give-way vessel alone, she shall take such action as will best aid to avoid collision. [Note: this includes inaction by the give-way vessel.]
(c) A power-driven vessel which takes action in a crossing situation in accordance with paragraph (a)(ii) of this Rule to avoid collision with another power-driven vessel shall, if the circumstances of the case admit, not alter course to port for a vessel on her own port side.
(d) This Rule does not relieve the give-way vessel of her obligation to keep out of the way.



The most common course alteration diagram for what to do, in extremis, when things get close, is this (Lott, USN, 1947).




The primary principles are:

1. Continue to follow COLREGS if possible. This means most turns are to starboard.
2. Don't turn into danger.
3. Don't turn broadside.
4. Don't increase closing speed (related to 4)

Simple enough. This dates back to WW II and before rule 17.


But is it different under sail? Let's assume that action must be taken in moments, even seconds, and only the helmsman is on deck. Let's assume it is blowing a bit and that the boat is not prepared to jibe or tack.


Do any of the angles change? Tacking or jibing unprepared could leave the boat dead in the water, which is not good, but changing the maneuver, in every case, increases the risk, if only a little. Either you are in a worse position or you are doing something unpredictable.


Also, different source quote slightly different angles, no doubt, for simplicity.





Discuss.

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The Wrong Way
and
The Navy Way