A coherent series of flat-file geotechnical datasets generated during the applied geology mapping of Exeter, Deeside, Coventry, Nottingham, Bath, Castleford/Pontefract, and the Black Country, and mapping of the Thame 1:50k sheet. For each of these projects, data were abstracted from the available site investigations within the mapping area. The structure of the datasets is limited, in that all geological and geotechnical data are attributed to 'samples' at discrete depths. The datasets include the more common geotechnical parameters, although some are entered as only class intervals, rather than in detail. All the datasets are held as paper coding sheets, with minor variations between projects. Most were digitised in Smartware and/or Statgraphics software and may not be readily accessible.