1. Consultant (Retired Chief Mechanical Engineer of the South African Railways), 83a Van Wouw St, Pretoria, Groenkloof, 0181, Republic of South Africa
2. Manager, Rolling Stock, South African Railways (Spoomet), P.O.Box 23, Johannesburg Station, 2134, Republic of South Africa
3. Department of Mechanical and Aeronautical Engineering, University of Pretoria, Pretoria, 0002 Republic of South Africa