Work Started Monday on two bridge replacement projects along Headquarters Road in Tinicum Township, Bucks County. Both bridges span the Little Tinicum Creek, one at Tettemer Road and the other at Cafferty Road, and they both date back to about 1910.  Headquarters Road will remain open initially while crews excavate for new foundations.   Look for closures in late March.  Farther west, Headquarters Road was closed between Red Hill and Tankhannen Roads last week after inspectors found a large hole in the deck of another bridge.