As we continue to develop a design proposal, one of our team becomes fascinated with the concept of reciprocation in timbered construction. In layman terms, a reciprocation design is one where each timber rests on it’s neighbor and their interconnectedness is what gives the structure it’s strength. A major use for this system would be to devise a method to span a large floor or ceiling with timbers that aren’t long enough to simply span the space.
As we developed the general outlines of a floor plan, it started to become apparent that we were in possession of timbers that would only work in the floor sizes we thought we would need if they were configured into a reciprocating system. This kernel of an idea would end up being one of the lynchpins of the overall design, as will become apparent later.
In this video, you see the journey of investigation, starting with various configurations we could do with the timber sizes we had, and then playing around with joining multiple systems together in a structure. Notice the double reciprocating floor with the smaller timbered reciprocating ceiling timbers above, holding two parallel chord trusses that allowed a non-symmetric wood and steel truss to complete the structure. Also, please notice the use of two entirely different reciprocating systems, one on top of each other, that you can see in the last few slides.
The truth that came from these investigations, and the start of the mathematical underpinnings of the final design, were that 15′ timbers, with a 30″ center to center reciprocation was both pleasing to the eye and the most effective use of the number of timbers we had. The final couple of images would end up being almost exactly the final configuration and would remain virtually unchanged throughout the extensive fine tuning sessions that are to come.