[PSUBS-MAILIST] deep test

Fri Jan 26 13:41:12 EST 2018

Thanks Al for the info.  A am aware of Alec's test apparatus.  I can do
essentially the same thing with my PLC.  I would just have to put a little
ladder logic in for the test that has a timer that opens the solenoid valve
that blow my MBT.  I want to hear what has worked for others then I will
modify the procedure.  You commented that you guys had no formal backup
plan if Snoopy flooded, what about with Persistence, did you have formal
plan to recover the boat if it flooded and if so what was it?

Cliff

On Fri, Jan 26, 2018 at 12:22 PM, Al Secor via Personal_Submersibles <
personal_submersibles at psubs.org> wrote:

> Cliff,
>
> The other unmanned test where the lines got fouled that you are referring
> to is when I helped Dan H. test Persistence in Seneca Lake.  The way we
> recovered was
> Dan and I brute force hauled the sub up by the line pulling had over
> hand.  At the time, the weather had picked up and there were pretty good
> waves on the lake
> making it pretty challenging with everyone else on the boat getting sea
> sick.
>
> I also helped Alec but he had a pretty neat method where he had an
> electric timer with solenoid valve which blew ballast at the end of the
> test.  Fortunately it worked like a dream since I don't believe he had a
> backup plan in case it failed.
>
> Al Secor
>
>
> ------------------------------
> *From:* Cliff Redus via Personal_Submersibles <
> personal_submersibles at psubs.org>
> *To:* Personal Submersibles General Discussion <
> personal_submersibles at psubs.org>
> *Sent:* Friday, January 26, 2018 12:39 PM
> *Subject:* Re: [PSUBS-MAILIST] deep test
>
> Hank, I have not worked the details yet but I can give you my tentative
> thoughts.  The location of the test will be Lake Tahoe in Ca on June 25-29,
> 2018 as you know, with Homewood Ca. as the base.  We will use a tender
> vessel that will setup over the dive site.  We will find a dive site with a
> bottom at a little past my max test depth of 375 ft.  I plan on ballasting
> up the boat so that when the MBT are flooded, the boat is about 20 lbs
> positive.  I will then attach a 400 ft line that has been marked every 10ft
>  to the bow lifting lug. When we are ready to do the test and you are ready
> to submerge Gamma, I will add 25 lbs of lead ballast wrapped up in rubber
> so it will not damage the boat on a line just aft of the viewport.  This
> location is just above the CG/CB of the boat.  Boat crew will slowly lower
> the boat until reaches the first depth station at 75 ft. We will stay on
> station for 5 minutes.  At any point if the bow line starts to add weight,
> we will abort the test and pull the boat up immediately. Divers will be in
> water and follow boat to  75ft stop. Gamma will be monitoring the dive all
> the way and down and back up.  Also, if Craig Busell can make this date,
> his Phantom T4 ROV will also be monitoring/logging the dive and giving us
> real time video feed on the surface which would be great.  The boat will
> then be lowered in 20% of test depth increments (75ft).  At each depth stop
> we will stay on station for 5 minutes.  If all looks good we will proceed
> to the maximum test depth of 375ft where we will stay for 30 minutes. We
> will then pull the 20 lb weight off the boat which should change the boat
> into a positive buoyant state.  Gamma and the Phantom will monitor the
> decent and ascent.  As a back up, the PLC on the boat will be programmed to
> automatically blow MBT at 2 hours from the start of the dive.  The PLC on
> the R300 will have logging turned on so at the end of the dive I can
> retrieve the memory card to interrogate all boat systems during the test
> dive.  I will look into a number of backup steps including seeing if
> a local dive shop has a diver with a rebreather that would be willing to
> dive to 375 ft.  We will make sure we have some kind of harness on the bow
> lifting lug that gamma can attach to in case we need her to lift the boat.
> If the boat floods, the weight will be 4400 lbs in the water so will need
> to see if can  locate a lifting bag large enough to lift the boat in a
> salvage mode.  We would not bring the lifting bag to the site but just know
> where to get one if the test fails.  The maximum depth the boat has been to
> is 160 ft last year.  If the unmanned test is successful, and surface
> inspection reveals no surprises, then I will take the boat down to 300 ft
> to establish the maximum operating depth of the boat.
>
> For those of you that have gone through this type of unmanned test before,
> I would welcome feedback. What worked for you and what you would do
> differently.  I can't remember which boat but I remember one psub unmanned
> test dive using a similar methodology in which the two line got wrapped up
> and fowled. Alec, was this you with Snoopy?  I don't remember how they
> recovered.  I remember the test was successful.  I am not to worried about
> the test as the crush depth is 1100 ft (in theory!)
>
> Still lots of details to sort out.
>
> I know you tested Elementary 300 pressure hull in a pressure vessel but
> have you done the unmanned test on her?  Also after rebuilding Nekton
> Gamma, have you done an unmanned test of her?  If so how did you do it?
>
> Cliff
>
> On Thu, Jan 25, 2018 at 6:40 PM, hank pronk via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
>
> Cliff,
> How are you planning to lower R-300 and how are you retrieving it?
> Hank
>
> ______________________________ _________________
> Personal_Submersibles mailing list
> Personal_Submersibles at psubs. org <Personal_Submersibles at psubs.org>
> http://www.psubs.org/mailman/ listinfo.cgi/personal_ submersibles
> <http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles>
>
>
> _______________________________________________
> Personal_Submersibles mailing list
> Personal_Submersibles at psubs.org
> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
>
>
> _______________________________________________
> Personal_Submersibles mailing list
> Personal_Submersibles at psubs.org
> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.whoweb.com/pipermail/personal_submersibles/attachments/20180126/033bbf0a/attachment-0001.html>