ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS
This hydraulic model investigation was concerned with planning and design of a single lift, 110- by 600-ft lock pintle to pintle, at the southern end of the Divide Section of the Tennessee-Tombigbee Waterway. Normally, an 84-ft lift condition will obtain, but a maximum of 92 ft or a minimum of 78 ft is possible at the site. A 125-scale model was built to study the filling and emptying system. The system developed in the model test was of the longitudinal floor culvert type. Culverts in each lock wall are connected to a crossover culvert with a horizontal splitter wall dividing flow to upstream and downstream tuning forks where equal division leads into the two longitudinal floor culverts in each end of the chamber, near the chamber quarter point. With the recommended design, the model gave filling and emptying times of 10.5 min and 13.3 min, respectively, with a 1-min filling valve and a 2-min emptying valve. The prototype can be expected to fill and empty about 18 faster 8.6 min and 10.9 min, respectively. Flow conditions in the lock chamber during filling were excellent with a very small degree of turbulence. The system developed is particularly desirable for highlift locks in that it is insensitive to misoperation i.e., dangerous surges in the lock chamber cannot be created by fast operation of the valves, nonsynchronous operation of the valves, or intermittent stopping of the valves during the opening cycle.