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Title: Navigation conditions and filling and emptying system, New Bankhead Lock, Black Warrior River, Alabama : hydraulic model investigation
Authors: United States. Army. Corps of Engineers. Mobile District.
Oswalt, Noel R.
Ables, Jackson H.
Murphy, Thomas E.
Keywords: Bankhead Lock and Dam
Hydraulic models
Hydraulic structures
Lock filling and emptying systems
Navigation conditions
Black Warrior River
Publisher: Hydraulics Laboratory (U.S.)
Engineer Research and Development Center (U.S.)
Series/Report no.: Technical report (U.S. Army Engineer Waterways Experiment Station) ; H-72-6.
Description: Technical Report
Abstract: The hydraulic model investigations reported herein were concerned with planning and design of a new single-lift, 110- by 670-ft lock (pintle to pintle) at the existing Bankhead Lock and Dam on the Black Warrior River in Alabama. Presently, tows negotiate the 69-ft lift at the Bankhead project through a double-lift lock with chamber dimensions of only 52 by 285 ft. Multiple lockages are required for all but the very small tows. Tests were conducted on two models : a 1:100-scale general model which reproduced the river for approximately 1.5 miles upstream and downstream from the dam and included, in addition to the proposed lock, the existing powerhouse, spillway, and lock; and a 1:25-scale model of the filling and emptying system for the new lock. Two basic plans (sites) for the new lock were considered and preliminary tests demonstrated that acceptable navigation conditions could be provided with the lock at either site. However, plan 1 required enlargement of the canal that constituted the upstream approach to the lock and plan 2 required a long dike in the downstream approach. Based on consideration of many factors, the Mobile District selected plan 1. Model tests then were directed toward detailed study of this plan and resulted in development of plan 1B. Navigation conditions were excellent in the downstream approach but were complicated in the upstream approach by surges in this canal created by filling the lock. An extensive study of these surges was made with a computer program (Appendix A), after the boundary conditions for this program had been established from data collected in the physical model. The filling and emptying system proposed by the Mobile District and developed in the model tests was of the longitudinal floor culvert type. Culverts in each lock wall are connected at the midpoint of the chamber to a lateral crossover system from which two longitudinal floor culvert manifolds extend into each end of the lock chamber. With the type 20 (recommended) design, the model gave filling and emptying times of 9.3 and 11.0 min, respectively; the prototype can be expected to fill and empty 0.5 to 1.0 min faster than did the model. Flow conditions in the lock chamber during a filling operation were excellent with a very small degree of surface turbulence. Unmoored tows in the lock chamber either rose vertically or drifted slowly away from the nearest gate. The system developed is particularly desirable for high-lift locks in that it is insensitive to misoperation; that is, 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.
Appears in Collections:Technical Report

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