Britain's concrete dams—the final 50 years?

Abstract

The second half of the 20th century saw over 60 large concrete dams built in Britain for a wide variety of water supply and hydroelectric reservoirs. However, with increasing social and environmental concerns about such projects, the Maentwrog gravity dam built 10 years ago could be the UK's last. The late Geoffrey Binnie described the development of concrete and masonry dams in the UK up to 1942, from Vyrnwy to Haweswater. This paper aims to complete that history. It describes the development of concrete dams, from simple mass-concrete gravity structures to prestressed and double-curvature arch designs, and the effect of improving technologies. It also looks at how the expertise of UK dam designers has been exported worldwide and concludes with a brief review of the World Commission on Dams report.

Industrial innovation: case study of the Claerwen dam

“…Taking account of this criterion, the dam's cross-section related its base width at any horizontal plane, to depth below maximum water level (taken as B1 M above the crest), using a method developed by A. H. Naylor [4] (Morgan et al, 1953a). This innovative structural design method departed from the more traditional "middle third rule" -so called because its design ensures that under all conditions the resultant will always remain within the middle third section of the dam (Scott and Molyneux, 2001) and hence, remove any tendency for tension to occur (Salmasi, 2011). Resultantly, Claerwen's designed line of thrust is within the middle quarter of the dam (Anon, 1948).…”

“…(Though it is argued elsewhere that "cyclopean concrete" and "mass concrete containing plums" are one and the same; Holt, 2013c.) Variants have evolved to include arched and spherical component dams that yield more economical design, by transferring (water) face pressure into their abutments to retain physical integrity (Durham University, 2013); and other more complex forms of composite and concrete construction, employing, for example, precast and/or prestressed components (Scott and Molyneux, 2001). Welsh dams are famed for several reasons.…”