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Snort system testing

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  • Snort system testing

    Click image for larger version  Name:	BA944808-CD2C-4402-B4FB-F59D374FD1F5.jpeg Views:	0 Size:	84.4 KB ID:	140609Click image for larger version  Name:	BA944808-CD2C-4402-B4FB-F59D374FD1F5.jpeg Views:	0 Size:	84.4 KB ID:	140608Hi all, I have surface trimmed my Blueback which I have opted to set up using the Snort option. How do I test the submerged trim without actually using forward motion? I have tried opening the intake valve while surfaced and submerged by holding it underwater. I have not been able to have the sub stay at all submerged, the valve is working correctly, it is not blocked either. Maybe I have trimmed her with too much flotation so the addition of ballast water thru the intake has no effect? If I add weight she sits well below the waterline, and becomes unstable. Removing foam does the same
    bruce
    Last edited by biggsgolf; 06-13-2020, 12:54 PM.

  • #2

    Comment


    • #3
      This is how the ballast sub-system is plumbed for Snort:

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      This is the arrangement in SAS mode:

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      Last edited by He Who Shall Not Be Named; 06-13-2020, 02:21 PM.
      "... well, that takes care of Jorgenson's theory!"

      Comment


      • #4
        Originally posted by biggsgolf View Post
        Click image for larger version Name:	BA944808-CD2C-4402-B4FB-F59D374FD1F5.jpeg Views:	0 Size:	84.4 KB ID:	140609Click image for larger version Name:	BA944808-CD2C-4402-B4FB-F59D374FD1F5.jpeg Views:	0 Size:	84.4 KB ID:	140608Hi all, I have surface trimmed my Blueback which I have opted to set up using the Snort option. How do I test the submerged trim without actually using forward motion? I have tried opening the intake valve while surfaced and submerged by holding it underwater. I have not been able to have the sub stay at all submerged, the valve is working correctly, it is not blocked either. Maybe I have trimmed her with too much flotation so the addition of ballast water thru the intake has no effect? If I add weight she sits well below the waterline, and becomes unstable. Removing foam does the same
        bruce
        "Opening the intake valve". What intake valve are we talking about?

        Sounds like you have trimmed the boat wrong. I start by positioning fixed weight and buoyant foam in submerged trim (ballast tank full of water) first. Only after that is worked out do I reposition the foam vertically to achieve proper waterline in surface trim (ballast tank dry). But, that's just me... what the **** do I know.

        David
        "... well, that takes care of Jorgenson's theory!"

        Comment


        • #5
          David, thanks, talking about the ballast valve that lets air out to allow water in to submerge the sub

          Comment


          • #6
            Originally posted by biggsgolf View Post
            David, thanks, talking about the ballast valve that lets air out to allow water in to submerge the sub
            Vent valve.

            So, it won't open when you command a vent (which lets the air out of the ballast tank, and water to take the place of the air). Have you attempted to adjust it?

            Give me details of what is, and is not happening so I can walk you through this problem to an eventual fix.

            These pictures will help you with the correct nomenclature. If we speak the same language we can better communicate.


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            David
            "... well, that takes care of Jorgenson's theory!"

            Comment


            • #7
              David, thanks for the photos. I have the submerged trim completed. Just to be clear, I now reposition the buoyant foam that I installed above the waterline for submerged trim gradually downward, toward being on or below the waterline until I obtain the desired surface trim? I do not add additional foam below the waterline instead?
              bruce

              Comment


              • #8
                Originally posted by biggsgolf View Post
                David, thanks for the photos. I have the submerged trim completed. Just to be clear, I now reposition the buoyant foam that I installed above the waterline for submerged trim gradually downward, toward being on or below the waterline until I obtain the desired surface trim? I do not add additional foam below the waterline instead?
                bruce
                Correct sir. As adding or subtracting foam at this point will ruin your submerged trim. And, yes, the job now is change ONLY the vertical position of the foam -- lowering selected sections to at, or just below, the models designed waterline -- keeping at it till your boat sits at the proper waterline with the ballast tank dry.

                And, in submerged trim, you want about a half-inch of the sail sticking in the air.

                Almost there, pal. Keep up the good work.

                David
                The Horrible
                "... well, that takes care of Jorgenson's theory!"

                Comment


                • #9
                  Will do David, thanks!

                  Comment


                  • #10
                    David, she is almost good! My issue is now when she descends the nose drops, then the tail dips down then rises to just below level. I know she will be moving forward so maybe I am crazy, but would like her to descend evenly. Any ideas? Maybe a wee bit of foam near tail above the waterline? I tried to post a video but extension .mov is not allowed and all my stuff is apple....
                    bruce
                    Attached Files

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                    • #11
                      Oh, please pay no attention to the finish, I will be detailing her again.....
                      Last edited by biggsgolf; 06-21-2020, 05:22 PM.

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                      • #12
                        Take some of the above waterline foam and move it back a bit to get the ass end back up to a zero-bubble angle in submerged trim. To slow the bow going under too quickly as you flood the ballast tank try restricting one or more of the hull bow vent holes -- that will slow the venting of air from the bow as the boat transitions from surfaced to submerged trim.

                        Play with it. We having fun yet?

                        David
                        "... well, that takes care of Jorgenson's theory!"

                        Comment


                        • #13
                          Yes, lots of fun and anticipation, lol. As of this morning I can report that she is successfully submerged and surface trimmed! Thanks for all the detailed input that helped me achieve this milestone! Pool testing next week at my Corolla, NC Sub Base.

                          Comment


                          • #14
                            Excellent. You're a good student.

                            David
                            The Horrible
                            "... well, that takes care of Jorgenson's theory!"

                            Comment

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