DeBoer Seaview

[jim h]

Kerry you are very welcome. I have to get me one of these hulls I guess I got almost all the parts and drawings to build it . Think about the pump and using it like we talked about it will work and will set the hull up where it should be at surface trim. If you have to pay much more than what I quoted let me know and I will buy the pump at my price and send it to you and you can just pay me back. I have no problem at all with that.I am going to get some pictures for you be back in a bit.

Jim

[jim h]

[jim h]

How much are these hulls and can you still get them from Dennis?



Jim

[Subculture]

What sort of pump are they? Diaphragm based?

[jim h]

Lumbar pump from a chevrolet truck. Push -pull pump it can inflate a large ballast tank and pull it back down to a vacum . I been playing with these for awhile and they work great just have to use them in a large sub.


Jim

[ADDINGTON]

Submitted for your approval, my holiday build of a ballast tank for the 80:
Numerous variations of graph paper templates went thru mockup and layout trials to determine a size and shape for a tank that would provide optimal capacity,the ability to insert and remove, and.. keep virtually all of the floodable volume below the desired surfaced waterline.
The main body is a section cut from 6" O.D. acrylic tube with 1/8" wall thickness. This was clamped at the ends to conform for adhesion to endplates of 1/4" acrylic sheet. The shape of the endplates was determined by the graph paper templates.
The three internal baffle plates and vertical supports were made from .040 polycarbonate sheet.
The "roof" or lid of the tank is .020 sheet.(protective shrink wrap remains on shots below)
All adhesion was done with Weld-On #16, a syrupy solvent that bonds for keeps and when properly applied results in a waterproof seal

Length= 22"
Width= 5 7/16"
Height= 2 3/4"
Capacity= 120 ounces / 3.3 liters

Obviously I have no idea yet as to what kind of job this tank will do in the water. I do know from a previous tank build that the seemingly shallow arc of the lid is plenty sufficient to direct escaping air for complete venting.
I solicit all comment and advice about vent valve configuration, use of jimh's pumps or any other theories of optimum ballast system setup.
As the holidays had our cameras in use, please pardon the iphone photo quality.
-Kerry

[He Who Shall Not Be Named]

A very good job there, can't fault the design or fabrication technique. Keep the liquefied gas away from this tank or you'll shatter it.

David,

[LOFTDRIVER]

The Beast is Back

Hello Kerry,
Thank you for posting photos of your tank design for the big Seaview.The tank you have designed should do the job well.I see that you have fitted baffles into the tank to slow down water movment when moving .The only problem I can forsee is the type of water tight arangement you intend to fit your beast with,do you intend to build some of the the water tight compartment over this tank?
May be to hold the tank ballast systems? I have not done much more to my own boat at the moment as the workshop is far to cold at the moment to sit down and do any work.The idea I was thinking of was for a cylinder fitted inbetween my water tight cylinders and blown with stored compresed air.This I will sort out later.But you have given me some thing to think about.
And to every one a happy new year.
Loftdriver out

[Subculture]

I take it the tank will work unpressurised and either full or empty, else that design could cause problems.

Also are you fitting a trim tank. A big boat like this will really benefit from it.

[Subculture]

Alan, have you got room for a reservoir for a compressed air ballast system? I know the Seaview is a big boat, but last time I looked it over, you were pretty packed out in there.

[ADDINGTON]

Gentllemen and Mr. Moderator,
Thanks for the feedback. Yes, this is old-school with no added pressure to the tank.
Gas venting directly against acrylic a definite no-no.
I think decisions about trim tanks, etc. can, for me, only come after I see how things sit in the water.
While many proven ballast system designs could be viable for raising this hull to a surfaced waterline equivalent to say, a WWII fleet boat,the iconic surfaced trim beauty shot of Seaview is a much higher freeboard.
As a resource, you really can't beat the VBOTS DVD 'Season Two-Volume One,' which includes a special features chapter with tons of raw FX footage. Worth the price alone are the Lydecker overcranked shots of the 17-footer shot at low angle. One of the clips is some 70 seconds in length and shows a waterline that hits right around the bottom of the 4 bow windows. I would love to achieve a waterline where at least the top 80% of the windows are exposed.
This desired waterline dictated the height, profile and functional displacement of my tank.
One of the surfaced drive-by clips shows the model trimmed a bit heavier in the stern to get the windows clear of the bow wake/wash.
It prompted me to think that if my main tank achieved enough freeboard, perhaps a "sliding keel" could be biased a bit aft to kick the nose up for surface running only.
Another obvious design consideration for the profile/cross-section of this tank was how it would affect the overall layout of internal components. As you can see in the shots from my last post, there is some 3" of space in the hull above the tank.
So yes, my intention is for any ballast pumps or other associated mechanisms to be located above the tank. Since longitudinal space in any aft WTC/SubDriver would be precious, I might need the option of using the space above the tank for any components that do not absolutely have to be in the aft watertight compartment, including any half-ass sliding keel mechanism. The space foward of the tank I would imagine will be occupied by a sizeable battery, but we want to preserve some real estate here for the future, just in case one of you guys figures out how to launch an Aurora FS-1 from this mother.
-Kerry

[LOFTDRIVER]

The Beast is back

Hello Kerry and Subculture,
On the subject of trim tanks I was thinking of fitting one in the bow to raise it up to get the water clear of the windows. Where I have the water line on my boat is about right to achieve this.This tank would then flood or do some thing to get to a level water line and then the main tank to flood to submerge her. I do have room In my own boat for a ballast system and some sort of air bottle, as the large water tight cylinder has nothing in it as yet. I was even thinking of going back to the large latex bag idea, but made from an old wet- suit or something similer. But first, I need to get her back to the water (when the better weather comes) and experiment further. I would like to get her submerging on a level trim first, then think about more complex ideas when I know the basic principles work.

Loftdriver out

[Subculture]

Here's my outline for a ballast system for the Seaview. Simple and cheap, but will allow you to hover your boat and easily compensate for different water density. Both tanks are cylindrical, the main tank is 120mm diameter at about 200mm long and the trim tank about 50mm diameter and 100mm tall.

The main tank is vented, and the centrifugal pump only has to be run to blow the main tank. An large cross section valve at the bottom will allow the main tank to flood. This valve would need to be custom built, as I don't know of any valve this size available commercially. As it only has to deal with very low pressure, it could be made quite simply.

The trim tank is fed via persitaltic pump, it should be cylindrical, and mounted upright to avoid sloshing. A small hole under 0.5mm could be drilled in the top to allow air to vent out, but the hole would be too small to allow water in (surface tension). If you wish to keep the tank completely sealed, it should be enlarged to about 300ml and the main ballast tank enlarged to suit.

Alternative trim tanks could be a single piston tank mounted laterally (e.g. a cut down Engel tank), or a pair of 100ml syringes driven by screw jacks or by peristaltic pumps at each end of the main tank.

[deepwater]

Hi Guys! Watched the dvd season two, volume one, on the special effects that Kerry was talking about. I had the dvds over a year and never knew about the sfx. Anyway watching your guys build got me excited. I blew of the dust on my seaview and took some measurements for a ballast system. I took a picture, I hope it turns out ok. This is the first time posting a picture.
Take care
Dennis.

[ADDINGTON]

SubCulture,
Your ballast tank system is ingenious and yet another good idea to factor into my planning.
The tank profile, however, is a bit tall for my desired surface trim,
which limits functional tank volume at around 70mm high inside the hull.
Deepwater,
Really great to see you here.
Looks like 2010 could be the Year of the 80.
-Kerry