St. Lucie Lock and Dam Dewatering and Maintenance Repairs 2012
Before major lock maintenance and repairs can take place, the lock must be dewatered so that inspections and repair work can be done in relatively dry conditions. Using a barge-mounted crane, the crane operator and rigging crew set a needle dam girder (I-beam) in place in notches built into the lock chamber wall. Then, they place large metal panels known as “needles” against the I-Beam to form a wall called a “needle dam.” (USACE Jacksonville District photo from a 2012 maintenance repair project at the St. Lucie Lock in 2012)