It seems that the ship you are looking fort was called the SS Queen of the
Thames of the Australian Royal Mail Line. Wrecked at Klippestrand near
Ryspunt on18 March 1871 while on her maiden voyage from Melbourne to
Britain. See "Shipwrecks and Salvage in South Africa - 1505 to the Present
" by Malcolm Turner. If you require more info please let me know.
Regards Ted Wille.