A report on the construction of underground cavities.

This report presents the results of a series of investigations to address possible lock operation problems. "Tests to determine operation forces on miter-type lock gates were conducted in a 5.5-ft-wide, 66.5-ft-long, 4.25-ft-deep flume equipped with a single set of miter gate leaves located approximately inthe center of the flume. Three linkages, with differenet kinematics of the operating machinery, were studied: modified Ohio River, Panama, and Ohio River. For each linkage, tests were conducted at gate submergences of 1 to 4 ft and at operating times of 10.1 to 40.2 sec. The effects of chamber length, bottom clearance of gates, presence of barges in the lock chamger, and nonsynchronous operation of the gate leaves also were investigated" (p. vii).

This report provides results of trafficability tests of the Army's Marsh Screw Amphibian vehicle in sand, clay, and silt. Various experiments tested speed, towing, slope climbing, and obstacles in different soils.

Summary: "This report provides data on the alluvial aquifer of the Lower Mississippi Valley in the area between Cape Girardeau, Missouri, and Port Gibson, Mississippi. Maps are presented of the Tertiary surface on which the alluvial aquifer rests as well as the geology of this surface and the areas where hydrologic recharge to the alluvial aquifer may occur. A set of piezometric-surface maps, together with hydrographs of observation wells, river stages, precipitation rates, and data on the hydrologic properties of the alluvium, makes it possible to calculate changes which take place in the aquifer. Further data are presented on the chemical quality of groundwater. The relevance of these data to engineering problems is discussed" (p. ix).