The Weston Tower, the first major addition to the Abbey since Hawksmoor added the Western Towers in 1745, is a 30m tall and a 6m wide 8-point star-shaped structure inspired by the 13th Century Westminster Retable, England's oldest altarpiece.
Given the historic significance of the site, archaeological investigations were started a year ahead of the main construction phase, which as well as informing our design approach, also expanded upon existing knowledge of the Abbey foundations, historic burials and the bases of the buildings which contained the first printing press in England. Wind tunnel testing was then carried out to minimise design loads and make the proposed foundations as small as possible.
A reinforced concrete lift shaft provides overall stability and a solid oak framed steel exoskeleton is stabilised by oak landings and stairs. The landings are 90mm oak boards, cantilevering 1.2m over their supports providing viewing platforms. A pitched roof with eight 6m long oak hip rafters with oak boards complements the Abbey roofs and turrets. An oak and steel framed bridge links the new tower with the Abbey. Oak dowels between the landing boards transfer the horizontal and vertical shear and stabilises the steel framing. Various dowel assemblies were tested, and the dowels were fitted drier than the board to tighten into their holes.
Research at a timber yard led to the specification for air-dried and green oak, from English and French sources, with limits on the moisture content, angle of grain, bow, sapwood, and age of tree. The position of the heart was specified for each member to limit long-term distortion.