REFURBISHING THE NAUTILUS MINISUB

PAGE SIX

"The tools and equipment are gathered; the shop is prepared; and we have the wherewithal to proceed.  The actual work of refurbishing the Nautilus begins now."

                                                     Pat Regan, October 2020

 

SHOP MORNING AFTER.jpg

In the midst of the Covid-19 pandemic lockdown, we worked on the salon window fairings and prepared the shop for major hull surgery.

 

 

DRIVETRAIN.jpg

We bench-tested the drivetrain again.  Several months of indoor storage hadn't affected it at all.

 

MOTOR TEST

 

 

HATCH OPEN.jpg

This full-scale functional mockup "proof of concept" device helped us develop how the new hatch opens and closes.

 

 

SALON FAIRING PLUG SIZE COMPARISON.jpg

This thin (still flexible) fiberglass shell will become a rigid plug for sand-cast aluminum fairings.

 

 

 

NAUTMINI LEVEL.jpg

We removed delicate items from the work area, put the dolly up on blocks aligned with the shop, and checked for straight and level.

 

 

TAILFINS OFF.jpg

Here I've cut the tail fin assembly off in preparation for installing the new drivetrain.

 

 

A3.jpg

The dolly was then removed and set aside.

 

 

TAILCONE PIVOT BEARINGS.jpg

The tailcone pivot bearing assembly was installed on the submarine.

 

 

A6.jpg

Positioned for welding.  The bracket top welds directly to the hoist vertical post; the sides were gusseted to fill the gaps.

 

 

 

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On the rollers with tailcone pivot bracket welded to the old hoist.  I will cut those rusted-out casters off and weld in a couple long pieces  of angle iron to connect the hoist with the rollers.  Don't want their relative positions shifting in the midst of hull surgery.  But after that, we're ready to roll.

 

 

KEEL 090 VERTICAL.jpg

After measuring at various points to ensure the Nautilus was straight up and level; an old carpenter's square placed flush with the floor and the keel indicates exactly 90 degrees vertical with no visible gaps between the surfaces and the square.  She's straight, level, and aligned with the shop. 

That last part is more important to accuracy than some might think.  Knowing she sits straight and level, plumb at the keel, means accurate vertical measurements can be made all along the length of the boat from end to end; critical to aligning the new drivetrain and external aspects of the hull and superstructure. 

Plus, anything that might affect visual perception (like a crooked alignment in the room) must be abated or eliminated.  That's what I've tried to do here.  

 

 

A4.jpg

Once I've added steel to stabilize the jig floor pattern; I'll (1) remove the upper superstructure framing and plating to access the pressure hull; (2) cut an aperture in the upper tailcone and ballast tanks for a motor-compartment access hatch; (3) remove the guidance control through-hull bosses from the tailcone; and (4) remove the entire upper cabin structure from the pressure hull.  That will complete the dissection of the submarine; after that, we start building again.

 

Tuesday, October 13, 2020: Been working on removing the superstructure.  Tried using our new Lotos plasma cutter; it has no problem with 1/4" mild steel but 1/2" is about all it can handle.  The frame for the submarine's superstructure is 5/8" square rod (solid; not tube) and the Lotos made a lot of dross.  So I fired up the Oxy-Acetylene torch and made quick work of it.  Tomorrow I'll take off the rest of the superstructure to get to the pressure hull in the cabin area.

AFT DECK REMOVED.jpg

 

 

Wednesday, October 14, 2020  3:22 AM: I continued working and completed the removal of the superstructure.  Here, for the first time in thirty years: the pressure hull's naviform cabin structure (originally designed for my earlier project, the HYPERSUB) is visible.  Next, I'll cut a hatch aperture for the motor compartment and remove the cabin structure from the pressure hull.

PRESSURE HULL EXPOSED.jpg

 

Saturday, October 17, 2020:  Since last time, I got her as level fore and aft as I can.  I shimmed the hoist about 1/2-inch and now the center of the propshaft and the ramming spur are both exactly 39.75" above the floor; sitting on the roller.

I also spent some time measuring where the cabin cuts will be made. 

To ensure that everything is as straight as I can make it, I've decided to build a wooden alignment jig (a rectangular framework of lumber) around the boat.  That's more expense and takes more time; but I do believe the results will be worth it.

The steel that's been exposed to the elements shows surface rust but nothing serious at this gauge. 

The ballast tanks were prepped with Salt-Gone and the plumbing has remained sealed since 1991; we expect the interior to look good and will know when I cut the motor compartment aperture.

The ballast tank exteriors showed a little surface rust and were treated with rust / primer converter and coated with a layer of fiberglass resin back around 1999 IIRC.  There's been considerable intergranular corrosion and exfoliation taking place under the resin as evidenced by the "zits" all over the hull; and I do expect that can be cleaned up.

The pressure hull exterior shows no corrosion at all.  It all looks nice and smooth and I was glad to see that after all these years. 

Oh, and since this is the first time in a long time that the pressure hull has been seen, let me preclude the inevitable observations with an explanation.

Yes, I know flat sides and angular surfaces are inferior to arched, rounded surfaces when it comes to making submarine pressure hulls.

There's reasons for everything.  Got it under control.  I know what I'm doing. 

She's reinforced and the design has already made seven successful dives. 

This is not a deep-diving boat and we operate under secure conditions following an agenda in accord with the boat's capabilities. 

Basically, she's a purpose-built manned submersible stunt vehicle; and for that role she's exactly as she needs to be.  

The forthcoming modification lowers the deck one inch; accurizes the "wheelhouse" design; turns the aft cabin hatch into a bolt-on; and configures the cockpit hatch to slide up and aft like the canopy on an F-86; for easy pilot access.  But it will still be shaped generally like the original; shown above.

 

Sunday, October 18, 2020: Jus' fer grins.  "The Nautilus Engine Hoist."  This is the device with which I will drop the new motor into the Nautilus and I thought it should be appropriately dressed for the occasion.  J

NAUTILUS ENGINE HOIST.jpg

66" Nautilus by Jim Key

 

TO BE CONTINUED…

 

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