Pat Ruddock, from Mann Williams, is the engineer behind the Four Elms project, which transformed a formerly derelict building in Cardiff into a state of the art new headquarters for the No Fit State Circus. Here he discusses his career and the challenges of breathing new life into an old building.

I have been a structural engineer since 1992. I was largely inspired in my career choice by my father, who was a chartered civil engineer: he spent much of his professional life teaching structural engineering to architects at the University of Edinburgh, and practised as a specialist in the conservation of historic bridges. I was fascinated by the projects he took me to see: I remember a trip to Switzerland where we toured the concrete bridges of Robert Maillart – their elegance was quite remarkable.

I have always valued working on projects which make a real difference to the communities they serve. These can range from church roof repairs to rescuing derelict buildings. Four Elms falls firmly into this category.

The original building at Four Elms was built in 1896 as a Sunday school, part of the Trinity Methodist Church next door. It fell out of use and became derelict around 20 years ago. I have worked on many conversions and ‘rescues’ of historic buildings, but Four Elms was unique. NoFit State knew exactly what they wanted, but not how to achieve it. As engineers, we were dealing with requirements well outside the norm for building structures. Fortunately there was a real clarity of dialogue between us and we quickly established the best possible solution.

There were two key challenges to the project: creating an uninterrupted space both large and high enough for circus performers to work and train, while avoiding the imposing of new loads which the historic structure could not sustain. To achieve this balance we had to remove iron tie bars which crossed the main space at eaves level (the top of the walls). However, as the bars prevented the weight of the roof pushing the walls outwards, we would have to insert a new structure to compensate.

The new rig solves both issues: it ties the walls together at eaves level, while providing a new structure from which circus apparatus and performers can be suspended. Essentially it consists of a series of steel ‘rings’ in a vertical plane, which follow the shape of the main space as closely as possible to maximise the space made available. The steelwork you see next to the roof and walls continues under the floor to create a ‘ring’, resisting the forces imposed on it well. A secondary benefit of the beams beneath the floor is that they provide concealed strong points - for example to anchor tight ropes, in the centre of the space.

In this respect the engineering is integrated very closely with the historic structure, while creating an entirely new function for the space. Plus, the rig is designed to be removable in future. It is only connected to the existing structure at roof level, and if the tie bars were reinstated, the rig could be entirely removed.

As well as the new structure we had to restore the derelict building. I have many years’ experience of conserving and refurbishing historic buildings and I find the process fascinating. Only once we properly understand a building and its history can we start to piece it back together, and help bring it back to life, often for a very different purpose than that for which it was originally built.

I’m pleased to say that the client is delighted with our work at Four Elms and has experienced overwhelming demand to use the new space. I look forward to more opportunities to regenerate historic structures, breathing new life into them so they may help their local communities for many more years.

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