Posted on January 3, 2022
Regularly changing the oil and fluids in your vehicle probably doesn’t rank high as one of the most fun and glamorous things on your to-do list.
However, it’s one of the most important things you have got to do to keep the motor running properly so you can check off those other, much more enjoyable bucket-list items – or at least avoid costly major repairs in the future.
At the St. Lucie Lock and Dam, along the Okeechobee Waterway near Stuart on the east coast of Florida, those maintenance repairs are due once more.
After a year of planning, coordination and notification, the U.S. Army Corps of Engineers will conduct a planned temporary closure of the St. Lucie Lock for major maintenance and repairs starting Jan. 4, 2022, with completion expected no later than March 31.
The three-month project will be the first total closure of the St. Lucie Lock in 10 years, and the first major maintenance of that structure in 26 years.
Maintenance is necessary to repair aging and damaged infrastructure, in addition to improving public and vessel safety. Repairs will require the lock chamber to be dewatered for crews to perform inspections, replace corroded steel structures, paint, install new gate seals, and clean Manatee Protection System components.
During the closure, barges, floating cranes and divers will be working in the lock entrance, requiring vessel operators in the area to use minimal speed and caution for safety.
The dewatering and repairs will be performed by Corps personnel at a total project cost of $4.7 million, which includes the year-long planning and coordination phases.
In order to execute and expedite this major maintenance project on the Okeechobee Waterway, where recreational and commercial vessels can save time and travel across the center of the state from Stuart on the east coast to near Fort Myers on the west coast, the Army Corps of Engineers, Jacksonville District, requested support from the Corps’ Regional Rivers Repair Fleet (R3F), part of the Great Lakes and Ohio River Division.
The R3F provides the capability to execute major maintenance and repair efforts. Their essential core capability includes specialized competencies such as miter gate replacement and repair, filling and emptying valve replacement and repair, and hydraulic, mechanical and electrical equipment replacement and repair.
“We want to do everything possible to keep our locks open for our recreational and commercial users. To do that, we’ve got to close the locks periodically for maintenance and repairs,” said Tammy Cleveland, Deputy Chief of the South Florida Operations Office in Clewiston.
“When we must close locks down temporarily, our goal is to identify and make the necessary repairs, and re-open the lock as quickly and safely as possible,” she said.
Regular maintenance saves both time and money, since emergency repairs take longer than planned closures, and are usually very costly.
“Corps personnel will be working hard — long 10- to 12-hour days, starting at 7 a.m. six days a week, Monday through Saturday — to get the St. Lucie lock reopened to vessel traffic as soon as we can do so safely,” said Cleveland.
Local boaters and fishermen will still be able to access Lake Okeechobee. The closure will only affect only vessels which planned to cross the full length of the Okeechobee Waterway from east to west during this time.
The four other locks along the Okeechobee Waterway, Port Mayaca, Julian Keen, Jr., Ortona and W.P. Franklin, will remain open for normal operations from 7 a.m. to 5 p.m., seven days a week, with the last lockage starting at 4:30 p.m. each day.
From January through March of 2021, there were more than 1,000 lockages through the St. Lucie Lock, the same period the lock will be closed in 2022.
Navigation interests and local marinas were notified in advance of the extended temporary closure several times in the past year, to get their input on the project and for planning purposes.
“The scheduled lock closure was planned to begin after hurricane season, and to be complete before hurricane season starts up again in the spring,” said Cleveland. “It’s critically important to have all of the locks on the Okeechobee Waterway open and operational during hurricane season, so vessels can travel quickly across the state to find safe harbor in advance of tropical storms or hurricanes.”
There are three reasons for the Corps to dewater a lock. One is periodic maintenance for things that we can predict. For example, over time, rubber seals will need to be replaced. It’s also a time to take care of repairs that have been noted previously, and to inspect and repair anything else that can be observed once the lock has been dewatered. Structures must also be dewatered for periodic inspections that require a full test on all structural elements, including the gates.
Periodic maintenance and inspections minimize the likelihood of having to close the lock for emergency repairs.
Work planned for the 2022 closure includes:
- A full inspection of the structural elements, including the sector gates which are the swinging “doors” at both ends of the lock,
- Inspections and the repair and repainting of the sector gates,
- the replacement of power conduit across the floor of the lock chamber,
- the replacement of all four gate seals,
- the rehabilitation of the cathodic protection system that protects chamber walls and sector gates from corrosion,
- the removal, cleaning, and reinstallation of the Manatee Protection System.
For some, it’s tough to understand why the process takes so long. To work on a waterway structure, it must be sealed and dried out first, a process called dewatering.
A temporary metal wall, similar to a “cofferdam,” must be placed across both ends of the lock. Materials must be staged in advance on a barge. Trained divers must inspect, clear, and clean the needle slot in the bottom of the lock chamber to prepare for the installation of the “needles” (large metal panels with gaskets to create a seal) to form the wall, known as a “needle dam.”
A highly skilled crane operator carefully places an I-beam into notches in the side of the lock chamber to start the process, and then strategically places the needles, into a small slot in the bottom of the chamber and in close proximity to each other.
During this time, trained observers are on site, looking for manatees and other marine animals in the vicinity during the in-water work. If animals approach the work area, their presence is reported to the responsible agencies, and work stops until the animal has moved away from the area on its own.
Likewise, if lightning is detected, work is also halted until it is safe to resume. The safety of the crane operator and everyone on site is always the top priority, during all phases of the operation.
Once the wall is sealed, the water must be pumped out to provide a relatively dry space to do the repair and maintenance work. Only then can materials, equipment and crews be lowered into the chamber using appropriate safety gear and procedures, and the inspections and repairs can begin.
“As soon as all of the repairs have been made, the process goes in reverse,” said Cleveland. “Equipment is lifted back out of the chamber, and then our crane operator can begin to pull the needles back out and rewater the lock. Watching the water flow back into the chamber after successfully completing a long and complex project like this one, is always very satisfying.”
“Lock dewatering and repairs are really a true test of teamwork,” said Cleveland. “Everyone is very focused and working intensely toward achieving one goal, day after day. The entire team is working together and dependent upon each other to reach the objective of getting the work done and the lock reopened as soon as possible and as safely as possible. It’s tough work, but it’s an opportunity for our team to shine.”
Related Photo Essay:
Lock Steps- dewatering is the first step before lock repairs begin:
http://www.saj.usace.army.mil/Media/News-Stories/Article/2304066/lock-steps-dewatering-is-the-first-step-before-lock-repairs-can-begin/
The St. Lucie Lock and Dam
The St. Lucie Lock and Dam is located along the St. Lucie Canal, approximately 15.5 miles upstream of the intersection of the St. Lucie River and the Intracoastal Waterway. The Corps constructed and currently manages five locks along the Okeechobee Waterway. The St. Lucie Lock was built in 1941 for navigation and flood control purposes. In 1944, the connecting spillway structure was built for flood and regulatory flow control through the St. Lucie Canal to manage the water level in Lake Okeechobee.
St. Lucie Lock and Dam Facts
Lock history: The first lock was built at this site by the Everglades Drainage District in 1925.
Cost of construction: Approximately $2 million total
Lift of lock: Sea level to current St. Lucie Canal water level. (14.5′ normal)
Lockages: Approximately 3,350 vessels lock through annually
Lock usage: Operating hours 7 a.m. to 5 p.m., with the last lockage starting at 4:30 p.m., 365 days a year, unless otherwise noted. Lockage usually takes 15 to 20 minutes.
St. Lucie Lock and Dam Technical Details
Lock chamber dimensions: 50 feet wide x 250 feet long x 10 feet deep at low water
Lock chamber type: Concrete and steel sheet pile walls
Lock gate type: Steel sector gates (pie-slice shape) installed in concrete gate chambers, operated by rack and pinion drive
Spillway: Concrete, 170 feet wide
Spillway gates: 7 electrically-operated structural steel tainter gates, each 20 feet long and 10.5 feet high
Spillway Discharge capacity: 11,000 cfs (cubic feet per second)
The Okeechobee Waterway
The U.S. Army Corps of Engineers Jacksonville District constructed, operates and maintains five locks along the 154-mile Okeechobee Waterway, which allows safe passage of vessels through the middle of the state, from the Atlantic Ocean near Stuart to the Gulf of Mexico near Fort Myers in south Florida. On the east coast, they include the St. Lucie Lock and Dam on the St. Lucie (C-44) Canal in Stuart, and the Port Mayaca Lock and Dam on the east side of Lake Okeechobee. The Julian Keen, Jr. Lock and Dam is located on the west side of Lake Okeechobee, along with the Ortona Lock and Dam and the W.P. Franklin Lock and Dam on the Caloosahatchee River (C-43 Canal).
USACE Locks along the Okeechobee Waterway are considered Mission Critical
Federal authorities require the United States Army Corps of Engineers (USACE) to provide mission critical support in the areas of life sustaining missions, interstate commerce, national security, and emergency management. Some specific mission essential functions include, but are not limited to, operation of water utilities, operation and maintenance of locks and dams, and emergency management efforts.
