Some protests were held in the Sandy Row area after news of the decision to dismantle the bridge was announced.
William III, or King Billy, is believed to have crossed the site on his way to the Battle of the Boyne in 1690.
Elements from the bridge were repurposed for the sculpture which is in Saltwater Square, the new civic space next to the station.
Richards, from the Golden Thread Gallery, said collaboration went into the design.
“I do a lot of my talking with a pencil, so as we’re talking, I’m sketching, and I think we came to this idea relatively quickly,” he said.
“I would have done the initial sketch, but I’d have done it as we were all talking, so I’m not sure whose idea it was.”
He said the team thought of other ideas but “came back to the one that stood out as actually being most appropriate in terms of celebrating and commemorating”.