Building Argonaut Jr
Dimensions: 14 ft long, 4 1/2 ft beam, 5 ft keel to deck, 7 ton displacement.
(1) The shallow ruts in the sand could not be the results of a 7 tons of submarine So the majority of Argonaut's ballast would have been removed when she was on dry land.
(2) Drawing seemingly make from photo (1).
(3) The Royal Navy Submarine Museum in Gosport, England, has a model of the Argonaut Jr. There are no plans or description of the interior details so this model was likely based on the same photos available to us and presented here. While it is very helpful to have the creators' input, it only represents a logical possibility. We are much obliged to the Royal Navy Submarine Museum for having provided detailed photos of the model. See: RN Sub Museum
(4) The Lion's Club replica is non functioning but they apparently lowered the height of the end bulwarks. I think that would be more likely as tall end bulwarks would have blocked the fore and aft view from the sail's portals.
(5) Another shot of the Lion's Club replica.
(6) Unfortunately the only photo with good detail shows Argonaut Jr. as a derelict.
(7) On the end toward the dive wheels there is an anchor capstan. There was an anchor on each side at different ends of the boat. This would allow the anchors to be lowered to the bottom allowing the boat to float up off the bottom in order to give more clearance for a diver to exit the bottom hatch. It's a logical conclusion as Simon provided us with a detail drawing of the Argonaut I that shows two such anchors at each end.
(8) This looks like an air valve. Possibly for a diver, but on the Argonaut I, Simon has the diver's air line deployed through the diver's hatch.
(9) Good detail of the viewport and what was likely a ballast tank vent.
(10) Iron strap for towing. One was located on each end. Another is pictured in #10 Flat bars are used to secure the ends of the longitudinal planks.
(11) (12) The rare top view of Argonaut Jr. contributed by Tim Smalley, shows that the ends are symmetrical. It was described as having the shape of a "flat iron" and that would be accurate as some antique flat irons were pointed at both ends. Today a boat builder might call the Argonaut Jr. a double ender. Also in this photo you can see what looks like the marks from two long hinge plates in the front side of the sail on either side of the view port.
(13) Deck with partial remains of the bulwarks.
(14) Argonaut: The Submarine Legacy of Simon Lake lists the man in this photo as Simon Lake's grandfather. He is apparently standing on a structure inside. Most likely the ballast tank.
(15) Tim Smalley enlarged and adjusted the contrast on the photo of the chain drive to reveal sprocket teeth. Now we know Simon used a type of roller chain. We were really pleased with the finding, because we had already decided to use roller chain for Argonaut Jr. 2010.
Argonaut Jr. 2010's Hull Design
We know nothing of the interior of the Argonaut Junior except what is subtly reveled by the locations of pipes are hardware on the outside of the hull. We also desire to build the Argonaut Jr. 2010; the modern version with features that Simon wouldn't have used on his original version of the Argonaut Jr. because the materials didn't exist, his budget money was limited or he omitted because he only needed Argonaut Jr. as a simply a proof of concept submarine. There was no need for the little pine submarine to survive beyond six or seven months it was needed to prove a point.
So at this point the the Argonaut Jr. of 1894 and the Argonaut Jr. of 2010 part ways. Epoxy laminated plywood sheets will insure that the hull remains structurally sound even though left in the water for months. It also provides a bonding strength greater than any glue available to Simon in 1894. The skipper of the Argonaut Jr. 2010 will also have the added safety of drop weights that can be released for the bottom of the hull. This will allow the submarine to surface even when it is partially flooded, the air supply is exhausted or one or more of the ballast tanks have failed. We will also use scuba tanks and not a soda fountain tank, and we will fill the tanks at a dive shop and not with a hand pump. We think Simon would be happy with the changes. :)
From the photos above, it looks like Simon built the original
Argonaut Jr's hull from two layers of 1 x 6 inch thick pine boards,
Back in 1894 an 1 x 6 board was really 1 inch think and 6 inches
wide. It was not the 3/4 inch thick, 5 1/2 inch wide board you
find in the lumber yards today.. Or 2010 version will use
plywood but only 3/4 inch thick on the sides and 1 inch thick on
most everything else. The reason we can use thinner material
is due to the additional strength of plywood. The 1 inch thick
boards Simon used were not joined together except by nails.
Each plywood sheet is make of multiple thinner layers of wood called
plies. Wood is naturally strongest along the direction of the grain
in the wood than forms as a tree grows. So on ply in plywood
will have it's grain running end to end and the next ply that is
glued to it will have it's grain running side to side. We will
then take 1/4 inches thick sheets of plywood and glue them to
together with epoxy to make thicker water proof sheets. So 3/4
inch think epoxy laminated plywood turns out to be better that two
layers of 1 inch thick pine boards.
Designing an ambient submarine so easiest to do if broken down into two steps. First you think about the submarine as an aquarium. Close the top hatch, then turn the whole thing upside down and fill it with water. An ambient submarine traps air underwater and that air pushed upward on the inside of the submarine with the same force that the water applies when the submarine is turned into an aquarium. Since we know the volume inside the submarine we know that the it will need to hold about 5 tons of force. The second step is to flip her back upright and empty the water out and attach all of the lead weights you need to keep 5 tons of air from taking you to the surface. And, you likely guessed it; that's 5 tons of lead.
(1) CNC cut one layer of plywood for the cabin deck. This will be used as a template for laying out the top and bottom laminated beams that from the curved sides.
(2) Layout two 4x8' sheets of 3/4" plywood, end to end and join them to make a base for forming the top and bottom longitudinal beams. Cover the base with plastic and screw 2x4 blocking to the base on 16" centers along the inside of the beams curve using the deck cutouts in step (1) as a template. Use epoxy to laminate 5, 1x4s together to form each of the curved bottom beams and 6, 1x4s for the top beams. Trim the beams to 14 feet and join them at the ends with a 4x4 using a mortes and tenon joint in the bottom beam. Use the template to mark and cut for the top beams to receive the vertical 4x4 frames.
The epoxy will be
AeroMarine 300/11 for bonding, and AeroMarine 300/21 faster drying
for the exterior coat. Coverage is 70 sq/ft/gal
(4) Install the bottom of the hull which is 4 layers of 1/4"
plywood laminated together with epoxy. Joints between the
sheets will be staggered. The bottom is glued and screwed to the
bottom beams and then routed with 1/2 inch deep grooves and pockets
to receive the 1 inch wide ballast tank partitions and vertical 4x4"
frames. One layer of 4" wide fiberglass cloth
will be used on both sides of the partition joints to create a filet.
(5) Install the 1" laminated top of the ballast tanks which is also the cabin deck. The bottom side of the cabin deck is routed with 1/2" groves to fit over the vertical ballast tank frames. One layer of 4" wide fiberglass cloth will be used to secure the ballast tank top to the tank partitions. The open areas at the ends of the ballast tanks will house a total of 6,800 pounds of lead bricks, and be covered with hatches cut from 3/4" plywood.
The deck will 1" thick and constructed like the sole and bottom.
(12) Finally the stanchions, bulwarks, bumpers and all of the wheel drive and steering hardware, etc. This is a view with the sides removed.
Building the Laminated Beams
Simon Lake likely had some large curved beams supporting the frame of his Argonaut Jr., but he may very well have picked them up from an old ship. In 1894 along the New Jersey coast large curved wooden beams would have available from dialect wooden ships.
Today, with large trees in short supply most large wooded beams are laminated or glued together from smaller pieces of wood. Laminating wood also has the advantage that thin planks of wood like the 1x4's we are using can be bent into a curved frame with wet glue between them. When the glue dries the boards can be removed from the frame but the glue will hold them in their bent shape. Next time you see large wooden beams in a building, take a closer look to see if they are laminated.
Second beam clamped in place. It only takes about 2 hours to do
when you have done it before. And it's great to have friends helping
out when you're getting the first one done.
CNC or Computer Numeric Control means that a robot is cutting the wood. We will use a CNC Router Table with 3 motors that move the router up, down and around the table in order to cut a piece of plywood that is laying on top of the table. Their is no need for measuring, marking, or cutting with a hand held power saw. Read more about Our CNC Table.
Find a friendly local lumber yard like M&M that will supports small projects for schools and buy some lumber. (1) There she is! Argonaut Jr. sitting on her trailer. Still a lot to be done, but 70 sheets of 1/4 inch plywood is a good place to start. We are using 1/4 inch Luan Plywood, it's not marine plywood which would be higher quality, but not higher enough quality to justify the 3 fold price increase. Read more about our Plywood & Glue.
We have used Computer Aided Design or CAD software to much of the design and planning for the Argonaut Jr. Read more about that here Computer Design. (2) The modeling work was all done in 3D so we convert those shapes to 2D and arrange them so they fit within 4 x 8 foot sheets of plywood. All of the parts will be laminated from multiple layers of plywood so color coding and labeling the sheets will help us sort out the many parts. The plywood is also 3 ply, meaning it is constructed from 3 layers of wood with the grain of the middle layer running from 4 ft from side to side and the top and bottom layers running the longer length 8ft direction or 90 degrees to the middle ply. This makes the plywood a little stronger from side to side, so when we glue up our
pieces from multiple sheets of plywood, we will do the same trick and turn every piece 90 degrees to one below it when possible. If you look at the layout diagram you can see that many of the pieces are on multiple plywood panels but they are turned 90 degrees.
CAD programs can save the drawing as in a file format called Drawing eXchange Format or DXF. The DXF then needs to be converted to a G-code file that will be used by the CNC machine. The G-code files also have additional instructions added for turning on the router on and off, lower and raising the cutting bit, and so forth. (3) We use LazyCam to covert the the
CAD drawing for part of the bottom and top deck in the illustration. The resulting G-code is basically move the router to the starting location, turn it on and the list each location it is to move to in an X, Y and Z coordinate. For example the line "X-0.1430Y9.9716" tells the machine to move the router to -0.1430 on the X axis and 9.9716 on the Y axis.
Finally the fun step we use Mach3 on the CNC machine to read the G-Code and uses it to control the router. The Mach3 software runs on a computer that is connected to the CNC machine with a printer cable. (5) A control box on the CNC machine takes the instructions and runs the motors on the table that actually move the router.
The curved sides of the hull will be formed just like the beams we laminated above. However we are laminating the flat parts too. There are three advantages, first we can simply butt joint sheets in order to make a single sheet of plywood that is 14 feet long for both the top and bottom of the submarine. Second, the epoxy provides a strong water barrier between each sheet of plywood. And third, we can use as many layers as required to achieve the strength needed for the specific part.
More on the Top Deck and Conning Tower
Putting on the Fist Side.
Sealing the Ballast Tanks.
Adding Plywood Layers
Kay completing the final epoxy seals inside the ballast tanks by working through the inspection portals.
Mike Bearden building a ladder that has made it easy to climb down. No more crawling thought the divers hatch!
Ballast Weights &
Fitting Her Out