This section describes the construction of the four carbon beams. In traditional Polynesian terminology these connectors are known as aka. For clarity and consistency, I use the more commonly accepted term beam throughout this website.
Construction of the beams
Where a ballast keel is one of the primary structural components of a monohull, the beams form the structural backbone of a trimaran. They carry the main loads between the main hull and the floats, and they are critical to both stiffness and safety.
Roughly a quarter of the F-39 plans deal with beam construction, which can look intimidating at first glance. I seriously considered outsourcing the work. If anyone would be the obvious choice, it would be Ian Farrier himself. His offer was very reasonable.
However, our personal circumstances changed after moving to a new house. The old house was still unsold, and with major purchases ahead—an engine and other costly hardware—I decided to proceed with the original plan and build the beams myself.
Beams chapter pages
The construction of the beams is documented in the following chapters, each focusing on a specific structural component and illustrated with a detailed photo gallery.
- Upper folding strut recess moldings ~25 photos
- Lower folding strut beam anchors ~25 photos
- Beam interior ~100 photos
- Beam exterior ~75 photos
- Beam sleeves ~25 photos
- Beam fairings ~125 photos
Fram’s launch took place “under steam and leaking water”, simply because the workshop had to be vacated due to the sale of the building. As a result, Fram went into the water as a technically seaworthy boat, but not fully finished in every detail.
This was clearly visible in the beams. At that stage they were not cosmetically finished, so the black carbon surface was still the dominant appearance. Peel ply was still present in places, and for UV protection I applied a thin coat of primer directly over the peel ply. This explains why, in some photos, the beams may look rather rough and untidy—the primer was purely a protective layer, not a final finish.
