USS John S. McCain Collision 20 Aug 17

[Stoker]

It was a close run thing.  It would have been a bad day if not for your quick reaction and that of your team, Chief 

My guys were the best.  I couldn't begin to imagine the pucker factor on the bridge and the close quarters you had to deal with.  SHA will have a brand new digital steering system when she comes out of docking this year, with dynamic positioning it appears.

 

[Lumber]

Another trend I noticed in my last ship was a tendency to leave the radar system in 'true motion' - that is, the course/speed vector was displaying the other vessel's true course and speed.  I was quite surprised that I had to prompt my Officers of the Watch to switch to 'relative motion'.  The true motion vectors let you see what direction the other ship is pointing, but don't give you any indication if there is a risk of collision. but switching to relative motion enables the OOW to determine much more quickly which ships are actually going to collide with you (or at least have close CPAs, because their vector will run through, or close to the centre of the screen, which is your 'own ship' position). It is a bit of an oversimplification, but it certainly helps to identify a priority contact.

I came up on old, old, old radar systems that didn't have ARPA and were only in relative motion, so that was the norm for me.  I run in Relative when I am on the Bridge and switch to True frequently, but Relative motion is my default.  I can only speak for my ship and two others, but the other Captains I spoke with reported the same trend...didn't make sense to us in terms of getting the 'best' picture....maybe that was a factor here, maybe not, especially if there was on over-reliance on systems, and particularly the auto-track feature.

I'm surprised you're surprised.

From the time I first sailed on MARS II back in '08 to now, the rule has always been that the Radar is to be left in True Motion at all time, and you are only to switch it to Relative Motion for a few moments before switching it back.

When I sailed with the USN '09, they did it the opposite, and it made total sense to me. Why not leave the radar in a way that allows you to take one look and see if someone is going to hit you?

However, my personal opinion on that has now changed. With experience, you don't need relative motion lines. I kind take a quick look at radar, and based on our leader lines, I can make a quick and more-or-less accurate assessment of whether a close quarters situation is developping with another vessel. This cues me to read the CPA from ARPA, take bearing, and switch to relative motion. Since the radar is in true motion, I know which direction all these ships are actually facing, which helps me build an accurate mental picture in my mind, which you can't do with relative motion leaders on.

:2c:

 

[Oldgateboatdriver]

Chief, dynamic positioning (which by definition means a computer controlling the ship so she can "hover" at a precise location and maintain her heading at the same time - not a different way of steering the ship) requires bow truster. Are the MCDV's finally getting their originally planned bow trusters after all these years?

 

[Stoker]

Chief, dynamic positioning (which by definition means a computer controlling the ship so she can "hover" at a precise location and maintain her heading at the same time - not a different way of steering the ship) requires bow truster. Are the MCDV's finally getting their originally planned bow trusters after all these years?

I was told dynamic positioning thats all I know.

 

[Oldgateboatdriver]

I'm surprised you're surprised.

From the time I first sailed on MARS II back in '08 to now, the rule has always been that the Radar is to be left in True Motion at all time, and you are only to switch it to Relative Motion for a few moments before switching it back.

When I sailed with the USN '09, they did it the opposite, and it made total sense to me. Why not leave the radar in a way that allows you to take one look and see if someone is going to hit you?

However, my personal opinion on that has now changed. With experience, you don't need relative motion lines. I kind take a quick look at radar, and based on our leader lines, I can make a quick and more-or-less accurate assessment of whether a close quarters situation is developping with another vessel. This cues me to read the CPA from ARPA, take bearing, and switch to relative motion. Since the radar is in true motion, I know which direction all these ships are actually facing, which helps me build an accurate mental picture in my mind, which you can't do with relative motion leaders on.

:2c:

My  :2c: : Why not avail yourself of more rather than less information? Unless things have changed since my days, there are two radar displays on the bridge of all our warships. They operate independently, so why not set the main one on true motion and set the second one on relative? The first one gives you a hint that there is a risk, then a quick glance at the second one confirms your evaluation - or not - and let's you observe any change faster. Moreover, in coastal situation, the relative motion display lets you snap a quick single parallel index line that gives you, at a glance, a quick re-assurance that you are on track without having to fix or look at the chart. 

 

[Baz]

However, my personal opinion on that has now changed. With experience, you don't need relative motion lines. I kind take a quick look at radar, and based on our leader lines, I can make a quick and more-or-less accurate assessment of whether a close quarters situation is developping with another vessel. This cues me to read the CPA from ARPA, take bearing, and switch to relative motion. Since the radar is in true motion, I know which direction all these ships are actually facing, which helps me build an accurate mental picture in my mind, which you can't do with relative motion leaders on.

We created relative motion tools for the digitized Sea King radar, to simplify both homings and Helicopter Controlled Approaches (HCA).  They would either use the calculated course and speed of a track or in the case of an HCA an entered flying course.  The HCA one was super simple; it showed an arc the aircraft would have to fly and then the approach radial.  Once on the approach radial you just aligned the relative track with the radial (remembering for aircraft relvel you are correcting for both the ship's movements and the wind).

Even though we proved they are better tools, use of the digitized radar and enhanced tools wasn't certified (as the software didn't have a DAL - design assurance level).

My personal opinion is that approaches shouldn't be flown to an autotracker for the same reasons you are talking about in the surface world.  Time and OT&E will tell for the Cyclone.

 

[Baz]

My  :2c: : Why not avail yourself of more rather than less information? Unless things have changed since my days, there are two radar displays on the bridge of all our warships. They operate independently, so why not set the main one on true motion and set the second one on relative? The first one gives you a hint that there is a risk, then a quick glance at the second one confirms your evaluation - or not - and let's you observe any change faster. Moreover, in coastal situation, the relative motion display lets you snap a quick single parallel index line that gives you, at a glance, a quick re-assurance that you are on track without having to fix or look at the chart.

As I have more than a passing interest and exposure to radar (albeit mostly airborne): why don't the radars allow both vectors to be shown at the same time, with clearly different presentations in order to distinguish them?  Wouldn't that allow you to understand how the traffic is moving in the real world, plus quickly identify those on a constant relative bearing (and by extension easily eyeball the CPA by extending that bearing)?

 

[Lumber]

As I have more than a passing interest and exposure to radar (albeit mostly airborne): why don't the radars allow both vectors to be shown at the same time, with clearly different presentations in order to distinguish them?  Wouldn't that allow you to understand how the traffic is moving in the real world, plus quickly identify those on a constant relative bearing (and by extension easily eyeball the CPA by extending that bearing)?

Or better yet, set a CPA alarm level (say, all vessels who will close to within 1nm of the ship). Leave true motion leaders on, except when a contact meets the CPA alarm criteria then the 2nd vector shows up.

 

[Baz]

Or better yet, set a CPA alarm level (say, all vessels who will close to within 1nm of the ship). Leave true motion leaders on, except when a contact meets the CPA alarm criteria then the 2nd vector shows up.

Quick: file a patent!

 

[FSTO]

Or better yet, set a CPA alarm level (say, all vessels who will close to within 1nm of the ship). Leave true motion leaders on, except when a contact meets the CPA alarm criteria then the 2nd vector shows up.

Doesn't the magic navigation box already do all that? I think it has the capability to show true and relative tracks of your contacts as well as their CPA.

But nothing beats looking out the windows and its amazing how fast that Gigantic Maru can sneak up on your beam if you are not paying attention.

 

[Eye In The Sky]

Another quick *I've never sailed and don't know how your Ops Room functions!!* question. 

As a RADAR op on the 140, I am responsible to raise/update the surface plot and maintain SA on the battlespace for surface and airborne tracks, whether we are at 300' or at 29k'.  We have specific procedures for the various situations and the RADAR op has the ability to direct the flight deck to take up a specific vector, etc, if needed.  Sometimes it is a recommendation, sometimes it is a "take vector XXX" IAW with our procedures. 

Don't your NES Ops perform a similar function as a RADAR op?  Wouldn't they be the first folks to notice a conflict?

 

[dimsum]

Another quick *I've never sailed and don't know how your Ops Room functions!!* question. 

As a RADAR op on the 140, I am responsible to raise/update the surface plot and maintain SA on the battlespace for surface and airborne tracks, whether we are at 300' or at 29k'.  We have specific procedures for the various situations and the RADAR op has the ability to direct the flight deck to take up a specific vector, etc, if needed.  Sometimes it is a recommendation, sometimes it is a "take vector XXX" IAW with our procedures. 

Don't your NES Ops perform a similar function as a RADAR op?  Wouldn't they be the first folks to notice a conflict?

NCI Ops will report contacts every set number of minutes, as directed by the OOW.  They do not give recommendations or commands.

 

[Eye In The Sky]

copy that.  I am really curious as to how the Ops Room functions now. 

 

[Baz]

copy that.  I am really curious as to how the Ops Room functions now.

I'm not an expert, and it's been a while, and it's not cut a dried, but: I was taught the bridge drives the ship, and the ops room fights it.  Any extra info to the bridge from the ops room is just that: info.

Edited to add: and I resisted the urge to say the bridge drives the *boat*

 

[SeaKingTacco]

copy that.  I am really curious as to how the Ops Room functions now.

If you come over to the dark side, I can arrange for you to learn....

>

 

[SeaKingTacco]

I'm not an expert, and it's been a while, and it's not cut a dried, but: I was taught the bridge drives the ship, and the ops room fights it.  Any extra info to the bridge from the ops room is just that: info.

My understanding is that the OOW has charge of the ship. The OOW can take as little or as much info from the ops room as they think they need.

Now, to be fair, the bridge radars are optimized close in work (say, less that 15NM). The Ops Room is looking out much further.

 

[Eye In The Sky]

If you come over to the dark side, I can arrange for you to learn....

>

I had a feeler question put to me in the spring about what I thought about an opportunity like that actually.  New airframe - pro, airfield and hotel options - con!  ;D

 

[Eye In The Sky]

My understanding is that the OOW has charge of the ship. The OOW can take as little or as much info from the ops room as they think they need.

Now, to be fair, the bridge radars are optimized close in work (say, less that 15NM). The Ops Room is looking out much further.

roger that

 

[Lumber]

Doesn't the magic navigation box already do all that? I think it has the capability to show true and relative tracks of your contacts as well as their CPA.

But nothing beats looking out the windows and its amazing how fast that Gigantic Maru can sneak up on your beam if you are not paying attention.

Especially at night, near the entrance to a major strait/canal, within dozen of ships at anchor, and dozens more entering/leaving said strait/canal, at night, with tons of shore lights...

And to believe I just saw a news headline that said "How to collisions at sea still happen?"... frig off...

 

[jollyjacktar]

And JJT, the PENELOPE incident was not a steering failure. It was an engine telegraph failure. In the steamers, there is is no direct bridge control. All engine orders are effected by the engineers blindly based on orders transmitted through mechanical telegraphs. In PENELOPE, the outboard engine telegraph failed and got stuck indicating full ahead and was obeyed by the engineers. So she both veered into PRESERVER and surged ahead at the same time.

BTW, one of the things that saved PENELOPE from a watery grave is that PRESERVER did not have a bulbous bow. PENELOPE was rolled over, some metal was crushed - but she did not become opened to the sea (which was great as the hit was at the engine room compartment level). To me that fact militates in favour of all naval replenishment vessels never being  equipped with bulbous bows regardless of the hydrodynamics advantages and fuel savings.

Meanwhile, we should all keep praying for the missing seamen.

Yes, you're quite right.  My mistake.

I am just reading the supplementary inquiry on the FITZGERALD, it makes for sobering reading.  I imagine much of the same conditions, post collision, will have been the same for the crew on MCCAIN as well.  My heart goes out to them all.