Timber domes in the Ipswich area

From 1963 to 1974 a unique series of domes were designed by my father, the Ipswich architect Birkin Haward of Johns Slater and Haward, in conjunction with the engineers, Felix Samuely and Partners. These domes were an economical way of enclosing a large clear space for sports and social use, mostly for local schools.

These structures consisted of a timber shell framework, following the geodesic principles promoted by Buckminster Fuller in the 1960s. Fuller had used a triangulated steel framework for large spherical enclosures as at the USA World Expo 76m diameter pavilion at Montreal in 1967. Meanwhile Birkin adopted standard timber struts with steel end plates, bolted together, spanning up to half that size. These were supported on concrete perimeter ground beams, sheet clad, waterproofed and lined, with openings for access, lighting and ventilation.

Early local domes had hemispherical forms with framing based on the icosedodecahedron, as the trial 6.4m diameter framework we erected at the Spinney, Westerfield Road in 1963 [see the illustration at the end of this article]. This was followed in 1967 at Dale Hall School with a 14.5m diameter complete version and then at Landseer School at 18.3m diameter. The varied triangular framework involved wasteful cutting of sheet covering and lining.

In 1969, a simplified 18.3m diameter segmental dome framework was adopted at Downing School, where almost rectangular covering panels contributed sufficient stiffness. However the circular plan did not suit most sports.

Alternative triangulated arcs had formed the faceted sides of the 18.3 x 36.6m Silver Jubilee School* dome in 1968 and the 16.5m square plan of Britannia Table Tennis Club dome in 1969. The latter incorporated chamfered hips at the corners for a more compact and contiguous shell form. Horizontal lines of triangulation allowed more effective sheet covering.

Further orthogonal plan versions followed, mostly square as at Guardian Royal Exchange Sports Club with 16.5m sides (since demolished) and the first larger version at Nacton Heath Secondary School** with 33.9m sides, in 1972. The latter could accommodate two tennis courts, six badminton courts and other sports, with a changing block along one side! During construction the bolted intersection tolerances led to a top deflection, requiring replacement multi-flanged junction plates after innovative computer analysis. A similar large dome was then built at Woodbridge School, in 1974, with the alternative junction detail.

Other rectangular plan domes followed in 1974 at Handford Hall School at 16.5 x 29.9m with hipped corners and a larger version at Thurleston School of 24.4 x 36.6m. The detailed structural design also benefited from computer analysis.

Constructional details using prefabrication evolved with the overall forms, but precision and careful sequencing were necessary for effective assembly. The silver external 'Evode' bituminous treatment protected the plywood sheathing while internal linings provided insulation, acoustic control, fire resistance and finish to suit use. Heating avoided airflow affecting badminton, while natural ventilation utilised stack effect. Fluorescent lighting at high level also became the norm. Overall costs were 25% less than the equivalent steel frame structure.

By 1975, restricted educational funding temporarily halted these projects and Birkin produced his comprehensive volume 'Timber Domes Developed in the Ipswich Area' as a record. In 1976 he was awarded the international Stuart Mallinson Gold Medal for Timber Research and Development. While a high level of design and construction skill was involved with this innovative development, an alternative economic basis for enclosing larger span spaces had been demonstrated. They mostly remain a distinctive feature on the local scene.

Bill Haward RIBA

*Silver Jubilee School. Now called St Edmund VI School (Bury St Edmunds).

**This was the Priory Heath Wing, later called Holywells High School, then closed late 2013. The dome is currently used by 'Inspire', but the site is proposed for housing, giving concern over the dome's future.