Re: [PSUBS-MAILIST] Surface Support Tug

Joe

I only have a big puppy dog to answere to, so I tend to think a little differently. :)' When I was speaking of adding a diesel motor and some length, I was looking at it as a different model of your submersible design that you or someone else could build that had extra range and speed. The design as it is currently is quite nice. Just a though but wouldn't it be cheaper to add a diesel motor and some length then to built a tug? Of course there are advantages to having a tender to.

With regards to the high pressure SCUBA tanks, if you have other tanks on you tender that together have a fair bit more storage space then all the ones that are on the sub you can use a long high pressure hose and just hook them up to the sub. To get the best effect you would have the tanks on board the tender properly secured and then all connected in a manor that they are essentially acting as one tank. In this way you can quickly charge your sub tanks to near the total amount they can take. Filling in this way is quick since the tanks will equalize with the tanks on the tender. In addition you could totally fill them if you have tanks on the tender with a higher psi rating. But you'd have to stop the fill at a safe point for the subs tanks and/or use a pop off valve to warn you. Then the compressor on board the tender can be compressing air for the tanks on board while the sub is submerged. This was a trick I came up with to deal with the people that would say that it takes to long to fill the air tanks for an compressed air engine car, so they didn't like air engine idea. I'm sure I'm not the first one to think of this my any means, but it was new to the group I was talking to. There is allot of new more effiecent compressed air engines being designed and built these days and so I've been looking into using them in subs above and below the surface. But that's a very big subject that needs it's own thread.

If you wanted to remove and replace the subs SCUBA tanks like you were saying. Then perhaps we could come up with a design of having the said SCUBA tanks be inside the saddle tanks but with access to them using some sort of sealable access door. If you fill them from the tender then you might not need the easy access door except for maintenance. In the current size of the soft ballast tanks it looks like you could fit one long SCUBA tank in each saddle tank and maybe one or two in the aft MBT, and one or two in the front MBT.

My favorite is to make the subs soft ballast tanks wider and just put them in the saddle tanks. This would give you even more freeboard stability. But as you say you'll have to do the math. It looks like you already have more ballast tank size then a comparable K-350 so your not likely going to need as high of a percentage of your tanks filled to be positively buoyant at operating depth. Then as you well know that air will expand and fill your tanks even more as you go towards the surface. I'm a fan of large soft ballast tanks to bring the subs higher out of the water and/or just get more stability from the wider ballast system.

When I was working on my live aboard 80' long trimaran submarine design I added allot of ballast to get her higher out of the water. For a short time I thought I had come up with something really new, since all the subs I saw were sitting very low in the water. Then I saw Simon Lake's Argonaut II and I was so sad. :)' Here's a quote about the Argonaut being up graded with greater buoyancy after Simon experienced how the sub really worked on a long ocean trip.

    "December 1898, Simon brought his little Argonaut to New York to be enlarged and re-outfitted with a variety of improvements including greater buoyancy, deck space, fuel capacity, a 60 HP engine and living quarters for a crew of eight. A searchlight was added in the bow to light up the fore-coming pathway, and telephones were installed throughout, so that conversation could be conducted between the divers and their tenders, with crew members stationed at different parts of the boat, with the surface or with the shore.

    Reconstructed by July 1900, the Argonaut II was 66 feet in length and capable of making a non-stop sea voyage of 3000 miles, and submerging for 48 hours. The new Argonaut looked quite different than the original one with the new raised deck that made the vessel appear more like a surface boat than a submarine. "

The pictures of the Argonaut before and after the upgrade is here.

http://www.simonlake.com/html/argonauts.html

As to the CAD file format I can use, my Solidworks can run hordes of different file types: ProE, STEP, STL, Parasolid, .sat, .vda, .wrl, and many more. Some file formats are better then others. STL is not that great for showing clean curves and since the articulating human is likely an assembly, that may not work well. I'll likely have to take all the different parts that make up the assemble and put humpty dumpty back together again. So if you could send the file(s) in a couple of different formats we can see which type will give the best result.

Brent Hartwig

From:  "Joseph Perkel" <joeperkel@hotmail.com>
Reply-To:  personal_submersibles@psubs.org
To:  personal_submersibles@psubs.org
Subject:  Re: [PSUBS-MAILIST] Surface Support Tug
Date:  Sat, 20 Jan 2007 03:44:52 +0000
>Thanks Brent,
>
>It would seem that I cannot export polygon meshes to IGES format.
>Specify another format and I will send you the file.
>
>""I was wondering if the four high pressure storage tanks attached
>just above your battery pods could be designed to fit inside of the
>saddle tanks?""
>
>.......I have thought of this a number of times for the very reasons
>you mention. The trouble that I run into, is that a few inches of
>extra width, translates to tremendous volumes for those tanks. If
>you blow this at or near the surface...ok...but when you start to
>want to try and comply with ABS standards for hp air reserve at
>operating depth, you run into a math problem.
>
>You are very correct, this would tow like a sea anchor but, the tug
>won't care much, hull speed is 6.29 kts anyway, she'll dig in (the
>tug) and push a wall of water out front like her larger cousins.
>Submerged, the drag won't be an issue but, entanglement could be.
>
>However, access to these as they are, would make up for the above
>detriments when replacing cylinders with a snorkel and fins
>offshore.
>
>As for the diesel electric motor room ala say.... Kraka......that is
>a dream scenario but....(me) got a wife to answer to! :)
>
>
>Joe
>