A collaboration between the artist Jamie McCullough and Atelier One. The first bridge was a private commission set in Blandford Forum. With a span of 8m, the bridge wasn’t a large or especially ambitious one at the surface, but the artist had one rule: he had to be able to build it himself.

Our challenge was to engineer the structure using as little material and connections as we could. Jamie found inspiration in an images of the Mathematical Bridge at Queens College, Cambridge. The story goes that the bridge, designed by Newton, had originally been constructed with no connections between the timbers. A phenomenal feat of engineering, it was taken apart by researchers who wanted to investigate how it was done. When they came to reconstruct it later, they found it impossible and today it is held together by nuts and bolts.

We started to talk about surfaces. Our rationale was that it is possible to build much stronger and stiffer structures utilising 3D forms. The quality we wanted was their ability to be able to resist localised loads whilst being able to span large distances with little material. Jamie spend long hours studying the maths. He noticed the similarity between the 2D surface of the Mathematical Bridge and the elevation of a toroidal surface was generated with straight lines, and our solution was born.

It was possible to create a 3D surface form from straightline generators and the requirement for fixing them together was purely to reduce their buckling length, a property of opposing curvatures or a synclastic surface. The deck layered into the toroid closure made of 55mm diameter iroko timber and the open surface, forming the overall structural.

The brief for the second bridge was for a practical yet sculptural piece commemorating the 550th anniversary of Eton college. This time the span at 22m was a little more taxing. Using the same principles as before we decided to create a 3D surface from straight lines and for Jamie to build the larger structure inside, in a boat builder’s yard.

The same 55mm diameter iroko was used and an iroko copse was planted next to the bridge location in order to replace all the timber used. Due to the configuration of the surface, the handrails – which extended above the deck – had to be split and steamed in order that the deck could be usable. The Queen opened the bridge in 1993.

Jamie was a genius, and it was great to have the privilege to meet and work with him. He died in 1998