Civil Engineering May 2021 | Vol 29 No 4

50 May 2021 Civil Engineering The saying, “a great tree has fallen” is par- ticularly apposite in the case of George, and all his ex-colleagues and friends extend their sympathies to his children Debbie, Johan, and Gerard. Hester, George’s wife of many years, passed away a number of years ago. What does one say about such a person as George? The terms used to de- scribe him by his friends and professional colleagues include, “a real gentleman in the true sense of the word”, “never flus- tered”, “always courteous and soft spoken”, “an enormous intellect”, “always willing to listen and help”, “in total control of his emotions”; and these are just a few. PERSONAL LIFE George was born in 1936 in Delmas on the East Rand and attended junior and high school in Nigel. George was a very private person, so many people do not know of the various facets of his life. I first met George nearly 70 years ago in 1953, and so am privy to many of his interests outside of his engineering career. His perhaps primary involvement was in Scouting where he participated over many dec- ades and attained the very senior position of Area Commissioner in the Scouting Association of South Africa. He, together with a Scouting colleague Jac Joel, was instrumental in compiling a very large (five boxes full) collection of all scouting stamps and first day covers up to 1989. He was also very involved with MG cars, the MG Car Club and the Sunrise Rotary Club. George was also a practicing Christian and an “Elder” in the St Columba’s Presbyterian Church in Hatfield, Pretoria. He had an extraordinary interest in the outdoors and nature, being a keen birdwatcher, a member of the Mountain Club of South Africa, and interested in photography, astronomy, and various other outdoor pursuits. PROFESSIONAL ACHIEVEMENTS All of George’s professional life was devoted to roads and transport research, and there is no one who would gainsay the fact that in his early career he was regarded as the top, and most knowledgeable, pavement design engineer in South Africa, in addition to having a high international standing. In fact, in his early professional years he was an important member of Prof. Carl Monismith’s team at the University of California, Berkeley in the USA, which laid the foundations and postulated the theory for the rational design of road pavements. Over and above that, he had an extensive knowledge of all facets of road and trans- port research in South Africa. George, to- gether with Dr Tony Williams, established the first road soil mechanics laboratory at the Road Research Institute of the CSIR. His achievements in the field of transportation engineering include some world firsts that would fill a book and are too extensive to list here. However, to give a flavour of his involvement in this field, a short description has been set out by a previous colleague Dr Emil Horak below. IN THE WORDS OF A COLLLEAGUE “The impact of George Dehlen on my career is profound. I remember him as one of the friendly faces even during my undergraduate studies as a bursar student, making sure we were well mentored in the darker art of research. For me, the most enduring link with George is the international reference to the ‘Dehlen Curvature Meter’. The Dehlen Curvature Meter was developed by him to measure the curvature or radius of a portion of a circle directly under a loaded wheel on a flexible pavement. It is still used as a criterion with more modern deflection measuring devices in evaluating the structural response of the upper portion of a base and asphalt surfacing. “I distinctly remember discussions with Australian road engineers in the early part of 2000 about how the calculation of such a radius of curvature is actually mathematically derived. I could use George’s original publications to answer that satisfactorily. Few people may know that he did his PhD at the OB I TUARY George Leveque Dehlen 7 April 1936 – 27 April 2021 “A great tree has fallen” It is with a great sense of personal and professional loss that we, his friends and colleagues, learnt of the death of Dr George Dehlen on 27 April 2021, just a few weeks after his 85 th birthday.