[PSUBS-MAILIST] more Esmae video

Fri Apr 15 00:19:34 EDT 2016

Hey Brian,

I was very impressed with how stable in roll Gamma became after Hank replaced the front ballast tank with the two forward saddle tanks. Exactly how Jim describes Snoopy. I hoisted myself out of the water over one of Gamma's saddle tanks while Hank was sitting on the CT, and the sub had no real roll tendency.  Perhaps a pair of saddle tanks forward and another pair aft would solve it.  You should expect that transitioning through the air-water interface while submerging and surfacing is when roll (and pitch) stability is the greatest challenge.

Tim

From: Personal_Submersibles [mailto:personal_submersibles-bounces at psubs.org] On Behalf Of hank pronk via Personal_Submersibles
Sent: Thursday, April 14, 2016 2:14 PM
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org>
Subject: Re: [PSUBS-MAILIST] more Esmae video

Brian,

Vance is dead right! don't cut into your MBT yet.  I can't tell you how many times I made a mess trying  to solve a problem.  I resisted make big changes with Elementary 3000 only to discover I had built the sub perfectly and just had it over weight.  Weird things happen.   Just strap the weights on first, you will learn a lot from that.  

Hank

On Thursday, April 14, 2016 3:02 PM, Brian Cox via Personal_Submersibles <personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org> > wrote:

I've got plenty of room in the bottom of my concrete ballast structure to put lead, which is actually slightly lower than the bottom of the sphere.  Just looking at the video I need enough to sink the top half of the sphere.  That works out to be around 2000 lbs or so of lead.  Volume of sphere is 65 cu ft.  Then I'll have to make sure it sinks evenly longitudily , so I may have of spread the weight out a bit or add to the nose.  

  Just scored about 1000 lbs of lead at the boatyard !    A wrecked sailboat keel  !     We'll make it work !

Brian 

--- personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org>  wrote:

From: via Personal_Submersibles <personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org> >
To: personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org> 
Subject: Re: [PSUBS-MAILIST] more Esmae video
Date: Thu, 14 Apr 2016 11:20:29 -0400

Brian,

Alec imparted some education to me one time on roll control.  When he added side ballast tanks to Snoopy, I asked why he had mounted them so they were partially above the waterline when surfaced.  He explained that when the vessel rolls to one side, the tank on that side then becomes more submerged and provides more "lift."  Simultaneously the tank on the other side rises and provides less lift.  The net effect is automatic roll dampening.

Jim T.

In a message dated 4/14/2016 9:18:04 A.M. Central Daylight Time, personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org>  writes:

Hi Alan,   Going to add a lot of weight to the bottom of the concrete ballast , at the very bottom.  Need to cut an access hole in that area so I can put lead bars in there and bolt them in.

Brian

--- personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org>  wrote:

From: Alan via Personal_Submersibles <personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org> >
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org> >
Subject: Re: [PSUBS-MAILIST] more Esmae video
Date: Thu, 14 Apr 2016 19:17:46 +1200

Another interesting video Brian.

I see what you mean about the stability.

Pity you couldn't have sunk her completely to see how stable 

she was once that big conning tower was under the water.

What's the next step?

I am not sure I am getting all the posts so apologies if I'm doubling 

up on any one else's comments.

Alan

Sent from my iPad

On 13/04/2016, at 10:19 am, Brian Cox via Personal_Submersibles <personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org> > wrote:

Hi All,

                Here is some additional video made by a friend of mine:

https://vimeo.com/162570037

Brian

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