Floors and Bulkheads and Flanges

So if you can remember back to the hull of the boat, or simply have a working finger that can scroll down, you will notice that the shape of the boat is there but there is no structural support.  This is where floors, girders and bulkheads play a part.  A bulkhead is fancy boat talk for a wall (going athwart and girder is going fore/aft).  A floor is just a bit of foam laminated athwartship that gives stiffness without blocking passage, essentially.  This boat has three bulkheads, two girders and five floors (technically two or three are nearly called rings but they are basically the same thing only differing in how high they go onto the topsides or deck).  

Two of the bulkheads were traced out using a very scientific device called a baked bean stick by clovegro, although I seriously doubt that that is what they are called out in the industry.  Ours was a simple piece of plastic that was about 600 mm long, 60 mm wide and tapering.  It has notches cut out like teeth on a saw but only like four of them and they are big.  It would be a lot easier to just put in a photo but I never took one and can not find the stick so I can only describe it.  We cramped in a large piece wood or mdf and then put the stick on the hull and traced the shape onto the mdf.  If this is done over and over following the shape of the hull you can then take the piece of mdf over and redraw it on cardboard and then you will have the shape the the bulkhead needs to be cut to.  Simple enough, right?  These two bulkheads prelaminated and then attached to the boat before the deck while the other one has already been discussed because we built that into the deck.

The main girder was lofted onto card board using the infomation from the autoCAD drawing and then cut and laminated.  This girder was prelaminated as well and then attached.  This girder was the one that would have the weight of the cockpit sole on it and would also intersect with the station 11 bulkhead creating a t-frame beam for more support, and run from the centercase to the transom.  Another girder which is built just like the floors is up forward near the collision bulkhead and ties together the three ring floors.

The floors were made using strip of foam that were about 8 mm think and 40 mm wide and the butting them together to go the width of the boat.  We hot glued them into place and then ran some carbon uni strips and then coved and fiberglass cloth-ed them into place.  Once they are hardened they are nearly impossible to bend and create a great stiffening support without adding to much weight or reducing cabin space.

The last bit of trickiness is the flange.  Because the station 11 bulkhead is, in fact, there we are unable to get inside the boat to cove and glass the deck in place once we drop it on.  So we built these flanges that can be squash bonded down onto.  the flanges were created by measuring the deck camber (curve of the deck) and the thickess of the deck and then attaching some mdf to the inside of the hull with some plastic tape (packaging) to the underside.  The we attached some peel-ply and cove and then used the fiberglass tape to make them.  After the resin set we were then able to remove the temp frames and we had the flanges.  This was also done for the transom.