Henry McKenna is President of Tension Technology International which is based in the USA and UK. He has extensive experience in rope manufacturing techniques, technology of fibre materials, rope handling machinery and systems design, accident investigations and industry sales and distribution.J. W. S. Hearle, M.A., Sc.D., Ph.D., C.Text F.T.I (Hon.), F.Inst.P, is Emeritus Professor of Textile Technology in the University of Manchester, UK.Nick O'Hear is Technical Director of Tension Technology International. He has more than 20 years' experience working with ropes and cables and has developed new electro-mechanical cables for defence and offshore applications and is currently working on non-destructive testing methods for ropes by means of fibre optics and Brillouin scattering.