<p> For the construction of the third set of lock complexes of the Panama Canal, a total number of 16 rolling gates were required in order to regulate water levels between chambers. Given that actions on gates differ between Atlantic and Pacific site, three different gate types were designed for each complex, resulting gate weights between 2060t and 3770t of structural steel.</p><p> Lock gates are constituted by an external skin plates at upstream and downstream, horizontal skin plate stiffeners, vertical column beams, horizontal and diagonal bracings, a buoyancy chamber in their lower part, which move during operation on an upper and lower wagon.</p><p> Governing analyses for structural lock gate design are fatigue, dry outage and seismic analysis.</p>

<p> The construction of the third set of lock sets is part of the expansion program of the Panama Canal. Aim of the program is to allow longer and higher loaded vessels to transit the existing canal.</p><p> The main components of the expansion program are:</p><ul><li> <p> Project of the third set of locks, the most important part of the program and topic of the present paper. Two lock complexes of three levels with water saving basins are built at each ocean side – one at Atlantic and the other one at Pacific side.</p></li><li> <p> Excavation of access canals</p></li><li> <p> Widening and deepening of access canals and elevation of Gatun Lake water level</p></li></ul>

<p> The third set of lock complexes (one complex at Atlantic site, the other one at Pacific site), were designed to permit Post-Panamax vessels to transit from ocean level to 27m higher Gatun level vice versa.</p><p> Governing hydraulic design criteria was to reduce lockage time making usage of water saving basins. Structural design was carried out taking into account usual, unusual and extreme load conditions.</p><p> Construction of both complexes is still going on, and, in order to fulfill construction site schedule, 10 to 15 lifts of a daily concrete volume between 3.000 and 5.000m3 are poured at each site for concreting independent reinforced monoliths.</p>