Iron Screw-Pile foundations were first introduced by Alexander Mitchell in the middle of the 19th Century for support of offshore lighthouses in shallow water ocean environments. Large diameter Screw-Piles with helical blades ranging from 2.5 ft. to 4 ft. in diameter were routinely used during this period and were constructed with either a solid iron central shaft (Screw-Pile) or a large diameter hollow cylindrical pipe shaft (Screw-Cylinder). Soon after their introduction, Screw-Piles and Screw-Cylinders were being used in pier construction, to allow ocean front piers to be constructed quickly and economically in many parts of the world, while at the same time providing adequate support for loads. A brief summary of this technology is presented and several examples of the variety of Screw-Piles and Screw-Cylinders that were used to construct ocean front piers are presented. Several examples of the application of Screw-Piles and Screw-Cylinders at specific sites are described using available historic records demonstrating that this foundation technology was well developed and well accepted by engineers
