Mysteries of the Chine

Replacing the chine logs was at the top of the list going into Irene Agnes’ restoration. The planks at the chine were soft, and the rust from the old steel fasteners was visible on the frames from the inside.

Removing the old chine showed just how bad it was. This wood and hardware may have been original to the boat’s framing in the early 1930s, and it had decayed badly. Some of the steel fasteners barely still existed.

Gussets vs Knees

For the most part, the chine was fastened to the gussets that bolted to the sides of the frames at the chine, rather than the chine fastening directly into the frames themselves. This was great, as replacing the iron-sick gussets was relatively easy, compared to replacing frames — only a couple of which needed replacement. However, these gussets do not show up on the redrawn plans currently being sold by WoodenBoat, which raised a bit of a mystery: Where did the gussets come from? Was this just an alteration by the boat’s original builder?

It turns out the original Sea Bird design did not use gussets, but rather incorporated internal knees made fast to the frames, similar to the current plans. However, in 1934, The Rudder revised the construction plans and their accompanying book How to Build a Cruising Yawl. Their new edition replaced the internal knees with gussets bolted to the frames. When WoodenBoat had the old plans redrawn for publication in 1981 by Dave Dillion, they went with the original arrangement. The month after the new plans were released, a Sea Bird fan and builder, Ted Lamary, criticized the publisher for the decision in a letter to the editor.

“The ‘old’ construction method will most certainly build a strong craft, but the method is bothersome and perhaps clumsy, at least to a lazy man like me,” Lamary wrote.

WoodenBoat responded, confirming that they had made a conscious decision to go with the older knee arrangement for mostly aesthetic reasons. “Our objections, admittedly subjective, were to the ‘busy’ appearance of gussets where show up inside the finished hull, and the fact that such gussets are dirt catchers. Somehow Larry Huntington’s way of building the original SEA BIRD, with grown knees reinforcing the chine and all, held more charm for us.”

The internal knee structure can be seen on Ida Rose, a centerboard Sea Bird built by professional builder Alex Hadden in Maine in 1987. Hadden did some extensive work on Irene Agnes a couple years later, but Aggie’s chines were not replaced or altered at that time. Still owned and sailed by Hadden, Ida Rose was featured in a 2012 issue of Small Boats Monthly, a magazine published by WoodenBoat.

While the gussets are easier and certainly simplified the replacement of the chine, I can appreciate the strength and elegance of the internal knees. Dave Strecker at Padanaram Boatworks, which is doing the work on Aggie’s current restoration, says he would go with the knees building one from scratch today, and I’m inclined to agree.

However, knowing that Aggie has gussets suggests when the boat was originally framed. The Rudder‘s plans and booklet, How to Build a Cruising Yawl, were revised in 1934 to show gussets and a change to the clamp. Presumably, Aggie’s builder had access to the revised edition, which would put the date of framing after that release. Unless, the gussets are not, in fact, original but were part of a later reframing. Extensive work was done on the boat in 1940.

Bevels and Bends

One of the original goals of the Sea Bird design was to minimize the number of bevels on the boat, making as much as possible able to be replaced with square stock. The chine is definitely the exception to this.

Following the plans for the chine as well as mapping off the old one, Dave and Keith Brown found a big shift in the bevel along the entire run of the hull. They’ve done an awesome job shaping the new chines to meet the bevel. The chine also takes quite a twist and lift as it approaches both the stem and stern. The new chine was steamed into place at the ends to meet this.

This is one area of building a new Sea Bird that’s worth noting, but doing it right – particularly at the bow – is central to the boat’s seakeeping performance. At the stem, the chine does not meet flat, but rises up to create the appearance of a curved bow. As a result the boat sheds waves excellently, staying very dry on deck while neither bouncing badly over them nor burying deeply into them.

Each of the gussets also is shaped individually to take the angle of the frames at each station. As they pulled the old gussets, Dave and Keith kept them numbered and cut new ones off the old. Replacing all the gussets was a huge part of ridding Aggie of the last of the galvanized steel fasterners. Most of the plank fastenings had been replaced in bronze in earlier restorations and work, and the remaining ones were replaced along with punky planks in this work.

Unfortunately, pulling planks to access the chines and gussets, and springing their ends at the bow and stern, uncovered other issues, particularly with the stem and transom. But that’s another story.

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