As Frank Manley drove onto the Tasman Bridge 50 years ago, he had no idea that a fully laden cargo ship had just crashed into it, leaving a 127-metre gap. It was a drizzly summer's evening, approaching dark. Frank was driving his family home to Cambridge from the Huon Valley. He hadn't even seen the ship. On January 5, 1975, the SS Lake Illawarra was en route to Risdon with a cargo of zinc concentrate.