A series of lateral load tests were conducted on assemblies of four, 4 foot long U.S. Steel PS32 (regular strength) and PSX32 (high strength) straight web sheet pile sections. The instrumentation adopted in the testing program was geared toward monitoring the assembly displacements, load transfer characteristics, and interlock response. Average effective E-ratios over three different pressure ranges were computed, interlock force versus pressure relationships were derived, the stress states in the pile webs were examined, and interlock force versus interlock displacement trends were obtained from the resulting data. A total of 12 assemblies were tested, 6 each of the PS32 and PSX32 types. Three tests from each lot of 6 incorporated pretensioning of the assembly prior to application of the lateral pressure; whereas, the remaining tests initiated lateral loading of the assemblies while they were in a slacked state. The results from the tests were generally grouped according to assembly designation (PS32 or PSX32) and type of test (pretensioning or no pretensioning). The tabulation of E-ratios and pile web stresses, and interlock force versus pressure plots revealed consistent relationships among tests in a particular grouping over the 0-30 psi loading range. Interlock force versus interlock displacement trends were physically correct, but provided no conclusive information regarding the response at an interlock connection. / M.S.