As the Panama Canal celebrates its centenary in 2014, a new set of expanded locks is being built near the existing locks at the Atlantic and Pacific entrances of the canal. After 100 years of operation the condition and performance of the existing locks is still impressive and significant as they will continue to operate even after the completion of the new third set of locks (TSL). The newly designed TSL will allow for the passage of larger post-Panamax cargo ships that can carry approximately three times as many containers as the existing Panamax ships can when traversing the canal. The new locks have been designed by a joint venture ( JV) led by MWH Global (US) that also includes TetraTech (US) and Iv Groep (Netherlands). The JV, contracted to design-build contractor Grupo Unidos por Canal (GUPC), has designed a new set of locks that have applied many of the lessons of the first canal in order to build a new set of locks that will address the needs of the Canal for the next 100 years.
A layout for the next 100 years
Both the existing and new Atlantic and Pacific locks move ships between the ocean and Gatun Lake and back to the ocean in three nearly equal steps ateach end of the canal, a total vertical distance of approximately 26m. This is accomplished using the principals of gravity, with no pumping of water involved, controlled by a sequence of hydraulically-operated valves that convey water from Gatun Lake through the lock chambers to the ocean. Availability of the locks for passage of ships is extremely important and critical to the success of such a large and heavily-trafficked canal. To accomplish this reliability, the current locks use two parallel lanes near each ocean entrance. In addition to providing for an efficient movement of more ships, this arrangement also provides a redundancy to the system that allows maintenance to be performed on one set of chambers while allowing the other set to be fully operational. For the new set of locks the owner, Panama Canal Authority (ACP), decided on a single-lane layout to reduce construction costs and also to avoid having to construct additional water sources to support the operation of the canal system with the new locks. The TSL chambers are approximately 50% wider and longer than the existing locks and are built to accommodate post- Panamax ships. The current locks consist of two parallel sets of three chambers, each 33.5m wide by 305m long, whereas the TSL’s single set of three chambers are each 55m wide by 427m long. And to accommodate a greater draft for the larger ships, the chamber wall heights have been increased to 33.5m from the current 26m. The single-lane design requires that the TSL have built-in redundant features to allow minimal downtime for maintenance. The TSL scheme has been designed to ensure continuous availability for 99.6% of the time. Achieving such high levels of reliability necessitated a detailed evaluation of all equipment and maintenance requirements, as well as ensuring that a robust, proactive maintenance schedule was in place.