original_query: What was the purpose of constructing a railway between Port Nolloth and O'okiep in Namaqualand?
query: What was the purpose of constructing a railway between Port Nolloth and O'okiep in Namaqualand?
answer: The railway was built to transport copper ore from the mines around O'okiep to the harbor at Port Nolloth.  Ox wagon transport was expensive and unreliable due to poor roads, droughts, and animal sickness.