A mechanical loading arm, used to transfer cargo containers to and from Mississippi River barges during an April demonstration at the America's Central Port facility in Madison County, could help make the Granite City area a major transportation hub and develop the nation's inland waterways as a freight shipping network, planners say. Local officials are breathing a sigh of relief this week after United States Steel Corporation announced it will keep its Granite City Works open, avoiding the layoff of 2,000 workers.