The Simple Joint (excerpt from work in progress)

 The problem set by the frame's design required exceptional joint efficiency but also spoke to the intelligent simplicity of primal structures. Taking advantage of the integrity of the grain Frei Otto and Ted Happold developed joints that would best respond to forces designed into the system: compression and tension joints.
The most challenging connection was the thin end of the tension member. To resolve the joint, Ted Happold and his buro suggested a metal pocket joint with many screws holding the member inside laterally. Due to the unpredictable distribution of wood fibers, structural timber components often require oversized mechanical fixings, increasing the required member's overall size and leaving a large amount of redundant material. This conventional approach has been tested previously, but in cases with low processed frame thinking, this would either lead to standardization of the ends which would reduce the strength of the material or uniquication of the pocket, which would increase the costs.
Frei Otto recognized this during the design phase and suggested a unique jointing technique allowing the timber to be sized efficiently in compression as well as tension. His proposition came in relation to the wind turbine connection invented and produced by Gougeon Brothers Inc. in Germany. Their connection used epoxy resin to connect threaded bars to glue laminated timber blades of a wind turbine. However, their tension joint served a different purpose, and it had to be adopted and tested on the round wood samples harvested at Hooke Park. Bath University colleagues performed tests of metal pocket and epoxy tension joints. The test results showed that the force transfer of the epoxy joint was ~96%, and the metal pocket only ~60%.
The liquid epoxy would be poured through a hole into a machined stepped opening with the threaded bar positioned axially. A hole in timber would let the air out of the joint. The epoxy glued each grain together while the treaded rod steps gripped the cast epoxy. The end grain condition was evidently in danger of splitting as the timber shrunk. To prevent this, a glass-fiber bondage was introduced to stabilize moisture content at the member's tip and evenly fix the layer of wood to the epoxy core. The bar was then connected to a ring freely adjacent to the ridge cable at the top of the roof. 
The compression joint was designed and manufactured similarly. The difference was that it would butt the front grain against a pre-cut surface on a perpendicular member. The threaded rod and epoxy would transfer forces further through the members, almost molding the centers.
Fabricating the common elements on the stock material required little skill but common sense. The team of carpenters included one experienced and several fresh unskilled workers. It aimed to produce a kit of parts that could be manually manipulated and processed on-site using simple hand tools and little workforce. Was it enabled by the simplicity of the idea to mold centrelines together or by the clarity in relationship with the other industries? It could also be that treating the trees minimally and only where necessary made the work run like a clock. It certainly was that relying on embedded knowledge of wood and reluctance to create superficial information that exposed the possibilities of timber and the efficiency of the joint.