The New Arms of the Canal
The gates of the Canal locks have new arms. Upon completion of the gate machinery conversion from a mechanic system to a hydraulic system, 80 hydraulic strut arms have been installed on the various gates in Miraflores, Pedro Miguel, and Gatun.
This project was started in January 1998, and includes the replacement of the original valve and miter gate mechanisms with advanced and more efficient hydraulic systems that require less maintenance.
To this end, the Panama Canal awarded a contract to the Rexroth Corporation of Pennsylvania for the manufacture of the new hydraulic gate operating systems, the dual motors required to power them, and computerized operating controls- at a cost of approximately $22 million, which includes the 80 hydraulic strut arms.
The design of these new controls was based on the very unique requirements of the Canal locks. Their miter gate system is so special that there is no textbook formula for calculating the load of a gate.
The original strut arm system, designed by Canal builders in the early 1900s, used a 40-horsepower motor to power a series of gears that turn a bull wheel. When the bull wheel rotates, a metal arm attached to it pulls a locks miter gate open or pushes it closed.
The new hydraulic system uses two 25-horsepower motors to power a hydraulic unit that pushes and pulls the lock gate. The advantage of the dual motor system is that if one of them fails, the other motor is sufficient to operate the system on a temporary basis. The computerized system has the advantage of using fiber optic cable that can carry more information than wire cable and is not affected by the lightning that occurs frequently during tropical storms. The fiber optic cable can also be used for other locks communication needs, such as the firefighting system and the office computer networks.
The conversion of locks machinery from mechanical drives to hydraulics incorporates the use of modern, programmable, logical controllers that ease a transition toward a computer-based control system that will enhance safety in operations, increase system reliability through equipment condition monitoring, and reduce maintenance costs.
