"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
In the midst of the Covid-19 pandemic lockdown, we worked on the salon window fairings and prepared the shop for major hull surgery.
We bench-tested the drivetrain again. Several months of indoor storage hadn't affected it at all.
This full-scale functional mockup "proof of concept" device helped us develop how the new hatch opens and closes.
This thin (still flexible) fiberglass shell will become a rigid plug for sand-cast aluminum fairings.
We removed delicate items from the work area, put the dolly up on blocks aligned with the shop, and checked for straight and level.
Here I've cut the tail fin assembly off in preparation for installing the new drivetrain.
The dolly was then removed and set aside.
The tailcone pivot bearing assembly was installed on the submarine.
Positioned for welding. The bracket top welds directly to the hoist vertical post; the sides were gusseted to fill the gaps.
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.
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.
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 in some places that's gusseted with 1/4 X 1/2" bar; from which the Lotos produced 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.
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.
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
66" Nautilus by Jim Key
Tuesday, October 27, 2020: Nothing to write home about; been hampered by an ear-and-throat problem last week and haven't made a lot of progress. Didn't want folks to think I was a slacker so I'm posting this. J
Decided against the wooden framing jig; I can do the same thing with two custom-made steel brackets, some cable and a few turnbuckles. Easier and cheaper. Glad the downtime gave me an opportunity to think about it; saved me from making a costly and time-consuming mistake.
Here's a couple random scenes around the shop: the removed superstructure and a candid view taken while I was labeling all the removed hull plates for temporary storage.
The little biker was my wife's idea; came with a bike replica from Harley Davidson in about 1/8th scale. He'd be a little less than eight feet tall if my 1/10th scale Nautilus was lifesize. J
Thursday, October 29, 2020: HULL REINFORCEMENTS.
I want to add some reinforcement rings to the pressure hull. Most folks would farm this out to a metalfab shop but I've got to find a way to do it myself; so I'm designing and building a ring roller.
This pic is an example of what one might look like but the actual design I'm presently developing is different. I'll be using a jack (scissors or bottle) to provide the bending force; scratch-building it out of old scrap steel, shafts, and bearings already in the shop from other projects. But they all work basically the same.
IMPROVEMENTS TO MANEUVERABILITY:
Basically, the Nautilus steers like a train. I want to add some 24-volt ROV thrusters (like these) sideways in the bow and stern so I can pivot the boat around its vertical axis. These are reversible, dry to 200 meters, and generate about 20 pounds of thrust: plenty enough to do the job.
As always, the modification is complicated by the need to conceal this within the Nautilus design. At this point, it looks like these will be transversely-mounted and hidden within the superstructure; the ends covered by spring-loaded "flaps" that open with thrust flow; or automatically close to conceal the aperture when the motors are inoperative.
TO BE CONTINUED…