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Pro Tunnel Race Boat Plans
Page Eight
Carlins and Deck Stringers

Now is as good a time as any to complete your cockpit drainage system.

At this point, water that flows through the limbers under the tunnel battens deadends at the tunnel sides. So you will need to cut notches, as shown, through the aft ends of the tunnel sides, AND the adjacent tunnel battens, all the way down to the tunnel plank itself.

Now water from the cockpit will flow into the sponsons, and drain from the sponsons through the drains you created earlier.

The carlins mark the intersection of the deck and the coaming. Again, as with all of the remaining stringers and battens, the carlins are sliced in half from the stem to bulkhead #2.

The carlins are held in place at the stem much the same as the tunnel battens were, but with the addition of small blocks, as shown, which I think you will find helpful. Thickened glue ensures they stay in place.

The distance between the carlins, where they terminate at the stem, is approximately 5 3/8".

The carlin is similarly held in place at the transom beam.

Note that although, in the picture, the carlin appears to be in contact with one of the tunnel battens, there is actually a 1/4" gap between these two members. The coaming will be installed into that gap.

The deck stringers on the inside of the tunnel sides need only extend to bulkhead #3 -- or just short of it as I did. Note that the aft end of the stringer is actually bent down below deck level. This was done in order to raise the level of the stringer between bulkheads #1 and #2 to match the height of the carlin.

The deck stringer on the outside of the tunnel sides extend all the way to the transom beam.

The final deck stringers, shown already in place, are located at the intersection of the deck and sides. However...,

... before you can install them, there are a couple of support blocks to be installed. These blocks provide some additional gluing surface for the forward ends of the outer deck stringers to stick to.

The blocks are approximately 3/4" x 1.5" x 6", and are glued to the inside surface of the sheer clamps and as far forward as they can be.

The forward ends of the outer deck stringers are glued to the top edge of the sheer clamp and the glue block you've installed there. There is no simple way to do this. The stringer must be cut off at a compound angle so that the cut lies with good contact on the sheer. Other than getting good contact, however, the cut does not have to be exact. You can correct any innacuracies when you bevel these parts prior to planking the sides and deck.

I cut my compound angle, by trial-and-error, with a drawknife, a tool I realize many will not possess. There are surely other tools that will make this cut including carving it with a wide chisel, or using a hand- or power plane, or with a handsaw, jigsaw, bandsaw or even a table- or radial-arm saw.

The piece is held in place at this end with a single long screw. I suggest you remove these screws as soon as you are certain the epoxy has cured enough to hold the stringer end in place. I left mine in for several days, and when I tried to remove them they were so securely glued in that they both broke off -- one of them near enough to the surface that it was in the way of the beveling plane and had to be dealt with.

Here's another task that can just as well be taken care of now.

If you are going to install a bow-eye on your boat, you will need a backing piece. I used a short length of 2x4, cut as shown, and glued down to the tunnel plank, two adjacent tunnel battens, and the bulkhead #1 beam.

Note the gap on the left side; you don't want this piece to become a water trap.

As soon as the glue cures it would be a good idea to drill the hole(s) for the bow-eye (I used the u-bolt type, but the single screw kind should work ok as well). At least don't wait too long because this area will eventually be inaccessable. You will, however, be able to reach into here later to install the nuts.

And then let's bevel what we have at this point and then install the upper sides. Go for a neat joint between upper and lower sides, but rest assured you can fill and sand this area to perfection later on.

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