Professor Brown's achievements are in Geomechanics and Engineering Education.

His main work in Geomechanics has been concerned with the analysis and design of underground excavations and this has led to co-authorship of two of the most widely used text and reference books in their field in the world,
"Underground Excavations in Rock" with E. Hoek and "Rock Mechanics of Underground Mining" with B.H.G. Brady.

He was elected Foreign Fellowship of the Fellowship of Engineering in 1989 and President of the International Society of Rock Mechanics during 1983/87.

He has occupied, with distinction, the positions of Dean, Royal School of Mines and Dean, Faculty of Engineering, University of Queensland.