Thanks for your help this has filled in a lot of gaps' .I still don't know how a 16 year got to South Africa in 1901 but I think there may be a bit to that story. He also served in ww1 from 1914 to 1918 and tried to enlist in ww2.Thanks again for your help.
I may have just discovered the answer to your question of how your grandfather made his way to South Africa. From the below article it appears that he was a stowaway with two others. The article suggests that he may even have been as young as 13 years of age.
(The Argus, Melbourne, Vic., Wednesday 28 Mar, 1900)