George Washington Bridge: Design of the Towers

The unusual type of tower adopted in the design of the George Washington Bridge is discussed in this paper. The entire load of the bridge is applied at the top of the inner columns of the tower and is distributed between all columns as the stress proceeds downward, until finally the reaction on the masonry is practically uniform. The paper demonstrates how this tower was analyzed; methods used to test, analytically, the efficiency of the design are related; stress-strain measurements on a celluloid model of a tower bent are described; and results are given of stress-strain measurements on the completed towers, which show the distribution of the load in the tower columns. These final measurements demonstrate the agreement between engineering theory and the actual behavior of the structure. Tests of large sized columns were made in conjunction with the National Bureau of Standards, and their results are reported. Conclusions are drawn as to the efficiency and safety of structures of this magnitude.