The 1938 record for the voyage to South Africa is on the FIND MY PAST site. This site is very good for outgoing ships records from UK to most parts of the world.
It gives you the choice of many varying destinations from the UK, including South Africa, and these records are for the period 1890 to 1960. You need to subscribe though.

It is just a pity my printer let me down or I could have sent you the record as an attachment.
Brian.