New Rudder

Last update: 4 November, 2005

     This is the proposed new rudder preliminary drawing. While many older boats and boat designs show a rudder attached to the trailing edge of the keel, this location is not ideal. For wooden boats it was often the most practical placement for ease of construction and strength. These limitations are not inherent in fiberglass boats.
     Bill Lapworth shocked the sailing world by removing the rudder from the keel, locating it farther aft and making it free standing. Provided that adequate strength is maintained this becomes an ideal alternative rudder placement. As an added benefit the rudder area can also be decreased. This combination increases the boat's tracking ability as well.
     The aft location increases steering force and the verticle or near verticle rudder post eliminates a lot of what feels like weather helm. When the boat is heeled this effect is very noticable because the rudder's force is now directed more to turning the boat rather than trying  to lift the stern and depress the bow.
     Partially balancing the rudder area forward of the turning axis also serves to make the helm lighter.
     Placing the prop in a somewhat clearer water stream helps to increase its efficiency.
     Another benefit of this arrangment is the relocation of the rudder post and tiller. I will make the rudder post long enough to place the tiller fitting at deck level. This will help free cockpit and cockpit floor space. It will also move the tiller a bit farther aft in the cockpit.

Proposed New Rudder

 

To start the rudder modifications it is necessary to remove the old rudder.
Unfortunately the rudder can not be removed without first removing the prop shaft. Someone missed the boat on this design!
This is where the gudgeon was installed. The four original fasteners were evidently removed and replaced with SS bolts. The holes through the hull are for four 3/8" pins, the removed bolts were 2 X 1/4" and 2 X 5/16". Then the entire gudeon and bolts were covered with a layer of what I think was Marine-Tex epoxy putty. It may have been epoxy but it sure didn't stick to anything very well. It was quite easy to chip off with a chisel, came off in big flakes. I suspect that the rudder was removed and repaired by a PO, probably due to water penetration.
The gudgeon and lower rudder pin. I was a bit surprised to find that the pin wasn't attached in any way to the rudder, it was simply slipped up into a hole in the bottom of the rudder. There was no noticeable wear between the pin and the gudgeon, perhaps the gudgeon had also been replaced.
Here is the new rudder post. It is a 2" SS pipe with a 1/4" thick plate edge welded to it. The plate is of course to transmit the turning force of the tiller to the rudder blade. The rudder blade will be laminated with 1/2" plywood and epoxy then whittled into a NACA foil. After shaping it will be covered with fiberglass and faired to a smooth surface, sealed with epoxy and bottom painted.
The start of the new rudder blade. The lamination is one layer of 1/4" ply and four layers of 1/2" ply. The area in front of the rudder post is not yet filled in. The skeg will be approx. 16" deep in front of the rudder post. When that dimension is finalized the remainder of the blade will be made.
The rudder shaped, faired and with one coat of epoxy.
The rudder post will pass through the hull inside this shaft log. It needs to be cut to length and fiberglassed into the hull. The log is made with a piece of schd 40, 2 & 1/2" PVC pipe. This is wrapped with four layers of bi-axial fiberglass and three bands of 6" cloth that encicle the tube four times each.
The shaft log will pass through this hole. As you can see it is right at the after end of the waterline.
The new rudder installed. The shaft log is epoxied in place. Building the skeg is next on this project list.
The new rudder installed with skeg. All is epoxied together and sealed.
The new trim tab for the self steering installed. The upper bracket attaches to the rudder post. The tab shaft is a 1" diameter SS solid shaft. The upper and lower support brackets are 1" X 1" X 1/8" SS angle.