The large lock at the Hiram M. Chittenden Locks in Ballard will close to all marine traffic from 8 a.m. until noon October 3 and from 11 p.m. October 10 until midnight October 11. The October 3 closure allows Navy divers to safely clean the maintenance gate seals. The 25-hour shutdown, beginning at 11 p.m. October 10, allows maintenance staff to test the new large pump’s dewatering capabilities.