I Know,  Lets make  Collage, FREE,

That way, will have  More people,
Waving a piece of paper, and saying:

  “Give Me that Job, this piece of Paper says I can Do It”

- - - - - - -

If you want to read something very Interesting,
  ( Read ALL you can find, in detail)
Check out, what,  ‘River Boat’, Pilots had to do,
before they got a ‘job’.

And you may even, get into small details, of that life style.
And all the Many, fascinating things, associated, with that Time.

  “River Boat a  Coming,  
                    River Boat a Coming”

justin_o_guy2 wrote on 06/18/17 at 15:37:55:

"...
Collage (from the French: coller, "to glue"; French pronunciation: )
..."

Thanks JOG, for, ‘Correcting’  the, ‘Auto Correct’.
  (Because I typed the word with a wrong letter)
Do you need the post, ‘Explained’, to you, because the word was not spelt correctly?

http://www.vesselofinterest.com/2017/06/mapping-acx-crystals-collision-with-u...

Can anyone give the Readers Digest translation of the
Maintaining Bearing even though they changed course?
This first comment is where it is.

don't have any answers as to why the Fitz didn't avoid the collision, but it wouldn't take much inattention to cause this collision.

I notice that the ACX Crystal seems to have slightly increased speed (from about 17.5kn to about 18.5kn) before its turn from 90 deg to 70 deg. Imagine the Fitz heading 90deg at about 17.5kn (which would likely be her most efficient speed with two engines, two screws). ACX Crystal is seen on a constant bearing, which means one of two things: the ships are on a collision course, or the ships are on an exactly parallel course with same speed. After careful observation, the crew on the Fitz establishes that the ships are both heading 90deg at 17.5kn and there is about a mile and half separation between the ships.

Now, what would it take for the ship's parallel course to change into a collision course? If one ship changed course and simultaneously increased its speed by the exact right amount, the bearing between the ships would stay unchanged while the distance between the ships closed. If one ship turned 20deg toward the other, it would have to increase its speed by about 6% to keep its bearing constant (as observed from the other ship). 18.5kn is about 6% faster than 17.5kn.

The crew of the Fitz, if they were just checking the bearing and not carefully observing the slowly closing range of the ACX for about 15 or so minutes, would have missed the impending collision.

Anonymous18 June 2017 at 18:40:00 GMT-4
Good answer, I believe CIC AND the bridge weren't paying as close attention to the range as they should have been. Tracking includes range and bearing readings. As far as I'm concerned this collision should have been avoided. On the old surface search radars (SPS-10) of my time we kept the curser on the contact and the range was read on a dial and the range and bearing was called out to the watch supervisor every few seconds which is passed on to the OOD.

Anonymous19 June 2017 at 05:35:00 GMT-4
I'm an ex SPS-10 tech and as such, know that the SPS-10 cant track vessels that close.. Too much sea scatter, thus the lookouts. I'm thinking that for some unknown reason, the lookouts miscalculated the Crystal course and speed, or, possibly never had her within sight.