This study developed a finite element program suitable for analyzing one quarter of a rectangular tank. A rectangular plate element capable of both extension and flexure was used with appropriate coordinate transformations to enable interaction of the floor and wall plates. Moment values throughout the tank were determined but not collected into tables because of their dependence on the width-to-length ratios and the height of the tank. A moment distribution type of method was developed so that critical vertical moment values could be rapidly determined without the direct use of a complex computer program. / Master of Science