In Memoriam – Assoc. Prof. Dr Ranko Todorović (30 November 1942–11 December 2019)

Professor Ranko Todorović left us on December 11, 2019. The mining profession, especially the fields of mining measurements, rock and ground movements and subsidence damages, has lost a world-renowned expert.

He became involved in the mining profession and chose to study mining engineering as a high school student during his summer holidays in France with his uncle, who was the owner of a mine at the time. During his studies, he participated in the educational process as a demonstrator. As a student, he was active in the International Association for the Exchange of Students for Technical Experience (IAESTE), where he organised student exchanges or professional internships. He attended two of these internships himself – at several English coal mines and at an iron mine in Kiruna, Sweden. He completed his mining studies in 1967 with a bachelor thesis in mining measurement, for which he received the University Prešeren Award for Students.

After serving the military, he worked at the Idrija Mercury Mine for 3 years as the Head of the Department of Mining Survey, Slovenia. In October 1971, he began working as an assistant at the Chair for Mine Surveying and Applied Geophysics at the Department of Mining of the then Faculty of Natural Sciences and Technology, University of Ljubljana, where he was to spend most of his career path. From October 1974 to May 1982, he worked as a mining engineer at the Geological Survey of Slovenia, while continuing to work as a contractual associate for the faculty (initially as an assistant and later as an assistant professor), where he was hired full time in July 1982. In December 1986, he completed his PhD in mining damage; the following year, he was first elected to hold the title of Associate Professor of Mining.

Professor Todorović was the Head of the Chair for Mine Surveying and Applied Geophysics for many years. He was also an honorary member of the International Society for Mine Surveying (ISM) and, for several years, he was the President and member of its Committees 1, 2, 3 and 4. He organised several professional symposia in Slovenia and, earlier, in erstwhile Yugoslavia; he had a wide circle of international colleagues, some of whom also became his friends, including Professor Eduard Czubik of the Montanuniversität Leoben, Austria, and Professor Bernard Drzezla of the Silesian University of Technology in Gliwice, Poland.

He wrote and spoke fluently in French, English, German, Slovenian, Serbian and Russian. He would only confirm so much, while we concluded that he also spoke Spanish, Italian, Norwegian, Polish, Czech, Slovak, Macedonian, Ukrainian, and so on; he corrected us that he could only communicate the basics in the mentioned languages. I have listened to many conversations that the late professor conducted in languages that he “can only use the basics” in with native speakers, and I can testify that they have never resorted to using another language. Professor Todorović always enthusiastically participated in professional discussions and unselfishly assisted his younger colleagues. Many of his ideas first appeared in the works of his doctoral students, but he never allowed these ideas to be presented as his, saying “We did it together”. As a professor, he was considered the only one from whom students could receive assistance with any subject they listened to while studying at the Department of Geotechnology, Mining and Environment. Students described him as a man who had forgotten more than they would be able to learn.

Professor Todorović has left behind a library full of professional books, as well as knowledge that will be passed on to new generations by his former students and colleagues at the Department of Geotechnology, Mining and Environment of the Faculty of Natural Sciences and Engineering, University of Ljubljana, Slovenia. He was an excellent designer of monitoring networks for movements and deformations. He also introduced a time component into the observations – he incorporated dynamic variables, and the measurements were not only a function of the “YXH” coordinates but also of the time coordinate “t”, so that the observation points that Professor Todorović adjusted also had the coordinate “t”. He was well versed in various statistical methods of submergence. The introduction of the “t” coordinate has been a great help in predicting damage, one of the most difficult practical problems that miners face.

He cooperated with all operating mines in Slovenia (Idrija, Velenje, Trbovlje-Hrastnik, Žirovski vrh) and left behind high-quality networks everywhere, as well as a very high number of the well-predicted consequences of mining. For several years, he was an associate of the Institute of Mining, Geotechnology and Environment; with his knowledge and experience, he was also involved in the construction of the Karawanks Tunnel.

After retiring in 2004, he focused most on enjoying the company of his grandchildren, but he continued to work with the faculty and was always ready to help as a counsellor. He will remain in our fondest memories.

Professor Ranko Todorović will be sincerely missed by his friends and colleagues. We send our heartfelt condolences to his family.

In the name of and in my personal name

Assoc. Prof. Dr Milivoj VULIĆ

Faculty of Natural Sciences and Engineering University of Ljubljana

Slovenia