[PSUBS-MAILIST] First Launch

Thu Oct 24 09:11:13 EDT 2013

Thanks for that Vance, your last sentence were quite revealing to me. My new project is a long two person, quite like the 350 in layout of the pressure hull, although with saddle tanks and a big dome in the bow. The weights and balances just kept leading me to a central tower despite the fact it looked better a little forward. It’s ended up with a centered tower, and the battery pods slightly aft to compensate for the weight of the passenger up front.

Best,

Alec

From: Personal_Submersibles [mailto:personal_submersibles-bounces at psubs.org] On Behalf Of vbra676539 at aol.com
Sent: Thursday, October 24, 2013 8:27 AM
To: personal_submersibles at psubs.org
Subject: Re: [PSUBS-MAILIST] First Launch

George left the sub alone while tacking on the aft extension because the passenger section was exactly that, an add-on, and he figured to deal with it as its own issue. Otherwise he would have to do exactly what you are talking about, which is to re-distribute everything and then be forced to do a new weights and balances chart.

I used to talk to him about this, figuring the passenger would be better in the belly and in front so he/she could see and participate more fully (like Snoopy). But the L-version sub in George's mind was a solo sub with a rumble seat, period. Anything beyond that was up to the individual builder. He didn't mind, but he wasn't going to join in.

As a side note, they miscalculated on the K600 and it wouldn't float correctly, so added the L-style hull section to hold the back end up, then shifted all the lead back there to balance it. Had to do it at the very last minute, but it worked sufficiently for Lloyd's to buy off on it.

Had they built hull #2,  according to George, it would have had a central conning tower on the 6' hull length. Even though it is dimensionally the same as a K-350L, it was never intended for two people.

Vance
-----Original Message-----
From: Douglas Suhr <spiritofcalypso at gmail.com<mailto:spiritofcalypso at gmail.com>>
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org<mailto:personal_submersibles at psubs.org>>
Sent: Thu, Oct 24, 2013 12:45 am
Subject: Re: [PSUBS-MAILIST] First Launch
James, Congratulations on your first launch! I am sorry to hear that you had to contend with some complaints, but you handled it well by moving along. Some people...

Anyway, I love you sub! Good job, and again, congrats on your first launch. ~ Douglas S.

On Wed, Oct 23, 2013 at 3:02 PM, Joe Perkel <josephperkel at yahoo.com<mailto:josephperkel at yahoo.com>> wrote:
Rick,

I have an accurate CAD model of a stock 350 hull and pods with assigned material densities. The software can make short work of determining changes in the longitudinal CG and what effects shifting the pods have. We would have to agree on a vertical datum, say the surface Edge of a hemihead for example.

As it lays now, the CG is right under the pilots butt, but it looks like George did not account accurately for the changes in buoyancy once launched. The trick would be trying to guess how far back to shift the CG. I can do this for you on my next group of days off if you'd like.

However, I like James idea of external movable weights as a better solution because you still have this 400 lb light condition to contend with anyway.

Joe

Sent from Yahoo! Mail for iPad

________________________________
From: Land N Sea <landnsea1 at hawaiiantel.net<mailto:landnsea1 at hawaiiantel.net>>;
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org<mailto:personal_submersibles at psubs.org>>;
Subject: Re: [PSUBS-MAILIST] First Launch
Sent: Wed, Oct 23, 2013 6:13:05 PM

I haven’t attached my pods yet to the pressure hull and after hearing about the aft positive buoyancy issue from a number of K-350 owner/builders I am now contemplating moving my pods aft one frame. I have all ready installed my drop weight threw hulls so I would have to extend the cross bar forward that goes between the pods for that plus not having any engineering experience, it would purely be a guess on what it would do to the trim. I doubt it would have the reverse effect and transfer the buoyancy problem to the front but not sure.
One thought I had was to bolt them on per plans but be able to adjust them aft as needed to attain the proper trim and then when I find the magic spot, weld in the bell reducers I have and connect the power cables. Any thoughts out their pro or con?

Rick

From: James Frankland
Sent: Wednesday, October 23, 2013 2:17 AM
To: Personal Submersibles General Discussion
Subject: Re: [PSUBS-MAILIST] First Launch

What im going to do is fix 100Kg under the aft tank, and then make the rest in blocks that can be moved around.  Then divers can place them with straps to the underside somewhere until its balanced.  Will make the blocks at the weekend.
On 22 October 2013 20:41, <MerlinSub at t-online.de<mailto:MerlinSub at t-online.de>> wrote:
Hi James congratulations,
- seems more and more that to light is a normal standard on launching Psubs.

May do not install fix weight in the stern next time. Install
it lose in the center and than trim it longitudinal on dive station
with move it forward or aftward or more in or out.
Its the fastest way to figure out the right weight and trim.

By the way Alan our overalls are red, and it help the skipper
to figure out which guy is in his crew and which not..
Also the guys with the brighter (many times washed out) overalls are the workers in the crew..
http://www.hansesail.com/uploads/tx_gorillary/2013_38_euronauttauchtauf_01.jpg

:-) vbr Carsten

"Alan" <alanlindsayjames at yahoo.com<mailto:alanlindsayjames at yahoo.com>> schrieb:
Congratulations James,
Look forward to the coming videos.
What a pain having to cut things short after all that effort.
Maybe you cold buy everyone a set of orange overalls like Carsten
does, to make things look professional.
Alan

Sent from my iPad

On 22/10/2013, at 10:06 PM, James Frankland <jamesf at guernseysubmarine.com<mailto:jamesf at guernseysubmarine.com>> wrote:
Hi All,

I got my boat in the water at the weekend for the first time.  Put the pictures up here.

http://www.guernseysubmarine.com/operations.htm

I didnt get any leaks at all, so i was super happy.  I wasnt really expecting to try and dive and would have been happy with just no leaks and a float test, but everything worked fine, so i gave it a go.  Unfortunately i didnt have enough lead.  I added 90KG (198lb) of lead, but it still wouldnt go down.  What i didnt mention on the website was that i was forced to stop testing because the harbour master came along to say that they had had an anonymous phone call from some bloody do-gooder who pointed out that we were using the comercial area of the harbour and didnt have a proper comercial dive team, which is officially a legal requirement.  So even though i had full permission from the harbour, i was forced to stop on a technicality.  They think it was some missery that has the hump on with harbour and just wanted to be awkward.  Shame because I was about to load a pile of anchor chain into the boat to get me more weight.

The boat did seem to be very light at the back and i kept squirting air into the forward tank to level it out.  Thinking about it, i suspect that the forward tank was settling into the correct position and it was the aft tank that was riding high.  Just need to get some weight at the back.  I had a slight list to port as well which i've no idea where that came from.  Again i will trim that up.

Anyway, i was really pleased with how it went on my first day.  Im meeting my divers tonight who took a load of underwater pics apparently, so i will see how they look later.  Might put some on the web if they are any good.

Kind Regards
James

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--

Carsten Standfuß
Dipl.Ing.Schiffbau @ Meerestechnik
Heinrich Reck Str.12A
18211 Admannshagen

0172 8464 420
WWW.Euronaut.org<http://www.euronaut.org/>
Carsten at euronaut.org<mailto:Carsten at euronaut.org>

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