The failure of fibre composites and adhesively bonded fibre composites under high rates of test, up to rates of about 15 m s(-1) were studied in detail. The present paper, Part I of the series, considers the experimental aspects of the mode I fracture of the fibre composite materials and joints. Part II will analyse the dynamic effects which are invariably associated with high-rate tests, and will show how these effects influence the observed behaviour of the test specimens. Part III will report the results from mode II and mixed-mode I/II tests on the fibre composite materials.