Screwpiles: The Forgotten Lighthouses

Further Advances in Screwpile Foundations – Combatting Ice Floes During the 1870s and 1880s, several lighthouses were lost due to ice damage. Deep Water Shoals Lighthouse was completely destroyed in 1867. To help alleviate the problem, the Lighthouse Board changed the foundation design, increasing the diameter of the cylinders and pilings. They also added extra pilings in the primary direction of water flow. Those pilings were designed to break up ice floes so they could not gather within the foundations of the lighthouses. White Shoal Lighthouse shown here exhibits the extra pilings—on the upstream and downstream sides—intended to break up ice floes.

The photograph of Windmill Point Lighthouse’s foundation below shows added tension rods and other ironwork to increase resistance to ice floes.

White Shoal Lighthouse Photograph by Major Jared A. Smith, 1885 NA RG 26 LG 25 84A

Windmill Point, 1912 NA RG 26 LG 25-79

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