Rib Construction
The first step in constructing the boat was to cut the rib arms, gussets, and rib bases. We created a new set of patterns trying to correct problems we experienced with the first two boats. We will gladly make these patterns available to anyone who is building a boat and would like to use them. They can be modified as desired but it is important to maintain the 5-piece rib design which really defines the appearance of an authentic construction.
The first 2 batteaux we built were tapered at the ends. This was accomplished by making the last 3 or 4 ribs each 2 inches narrower than the previous one. This was simple to accomplish by making the rib base narrower, no changes were made to the rib arms. The problems this taper created were in the planking stages. At the ends of the boats some of the planking boards which started on the bottom of the boat towards the middle, ran up on the sides as they approached the ends. This was a very difficult bend to make. The new Rucker and most of the other boats which have been built recently have no taper at all. This means that all the ribs from nosecone to nosecone are identical and planking is much easier
The joints where the rib arms meet the rib base pieces can best be understood by looking at the pictures accompanying this article. The joint is basically a rabbet joint with the rib arm thickness removed from rib base to accept the rib arm. The material removed from the rib base to make the joint can be done by a number of methods depending on equipment available. A dado cutter can be used making multiple passes. A skill saw can be used making multiple cuts the using a chisel to clean up the cut, in the past we’ve also used a band saw to make this joint. It’s not important that you have a cabinet grade joint, as strength not appearance is most important.
Fastening of the gussets, rib arms, and base ribs is done with boat nails. Care should be taken when nailing to anticipate where other nails will end up and also to avoid potentially splitting particularly the rib arms where the grain inevitably goes across the rib to some degree. Because of the shape of the boat nail, there is a correct orientation when nailing. The nail in one direction has much more of a wedge like configuration which will be more likely to split the wood. A close examination of the nail will make this concern clear.
The rib bases on the new Rucker are made from a 3 x 6 and the rib arms from 2 x 6. The decision to increase the base ribs to 3" was based on the fact that because of the way the lap joint is formed between the rib arm and base rib, if you use 2" rib bases you end up with about 1 ¼ " rib arms. On past boats we have had a lot of trouble with rib arms breaking, a situation which the 3" base ribs has completely eliminated on boats 3 and 4. The down side obviously is the extra expense and weight of the 3" materials.
After the ribs have all been assembled, they are laid out upside down on some type of frame. In the past we have constructed sawhorses, for this boat we laid out cinder block columns and placed doubled 2 x 4 rails the entire length of the boat. On previous Ruckers, the spacing between ribs was determined by the length of our planking boards. These began at 12 feet but with checking we determined that we would be lucky to get 11’6" out of the boards. This left us with rib spacing center to center of 26.5". The 2009 construction we used 35 foot lumber for planking to eliminate but joints so the rib spacing could have been anything we wanted. The rib spacing in my opinion should be between 24" and 28" center to center. The actual spacing should be determined by what is needed to eliminate waste on the boards which will be used for planing the boat. The ribs should be spaced and squared as closely as possible, we used strings on the ends of the rib arms. We also placed some rocker into the boat by shimming the center piers 2 ". We also did this on the previous boats but after a couple of years in the water, the boat straightened out on it’s own.
The end rib where the nosecone meets the body of the boat is an area which has been problematic on the first three boats we built as well as many other boats in the festival. A 3" base and 2" rib arm provide plenty of width for most all nailing including where boards end and will butt the next board. However because of the angle of the nosecone boards and the need to angel part of the end rib, it is extremely helpful to have more width to work with on this end rib. Some boats have a double rib at this location to provide the needed width, but we found that a 4’ rib arm mated to a 4" rib base worked beautifully and eliminated much of the trouble found at this joint.
The rib arm and rib base are nailed together and held by the rabbet joint on one side and a gusset plate on the other side. Don’t underestimate the importance of having a secure joint between the arm and base.
