The initial torsional stiffness of shells with interior webs
This is a 1935 NASA technical report, issued by the National Advisory Committee for Aeronautics, on the initial torsional stiffness of thin shells reinforced with interior webs, written for aircraft structural engineers. Its pictures are plain engineering drawings: dimensioned plan and section views of tapering wing and shell sections with web layouts, and a line graph of twist against distance from the wing centre line. A designer might draw from their ruled dimension lines, hatched cross-section layering and labelled stations as a stark diagrammatic vocabulary.
