[PSUBS-MAILIST] deep test

Fri Jan 26 16:50:57 EST 2018

Thanks Alec.

On Fri, Jan 26, 2018 at 2:55 PM, Alec Smyth via Personal_Submersibles <
personal_submersibles at psubs.org> wrote:

> No backup plan, but at least if Snoopy flooded the autopilot would vent
> the MBTs at the first sign of water in the bilges so if the flooding was
> not sudden she would come up. The autopilot vents MBT based on either of
> two signals; the timer going off or a hardware store flood detector doing
> the same.
>
> Best,
> Alec
>
> On Fri, Jan 26, 2018 at 1:41 PM, Cliff Redus via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
>
>> 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
>>>
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