You may remember that I promised some time ago to discuss each of the topics mentioned by Ken Johnson in his Timoshenko Medal speach. Here I take rail corrugation. Rail corrugation has been noticed at least for 100 years, but (particularly short pitch one in the range 20÷80 mm) has been considered an enigma because measured corrugation wavelength did not relate well with wear instabilitymodels.

We suggest this is mainly due to the intrinsic large number of parameters which has resulted in many independent efforts to generate models, many false beleifs, the difficulty to collect experimental evidence, and the lack of sufficient comparisons between models which has quite clearly not permitted to elucidate the main ingredients of the problem. Ken Johson himself has considered the problem an Enigma!

Recently, however, we have shown our own hypothesis over why this occurred, solving perhaps the "Enigma". In particular, while very complex models have been generated, often they are quite naive in one or more assumptions. Hence, the Gabriel Garcia Marquez quote... I attach a preprint of a paper I am about to submit about this.