Spit Bank Lighthouse: The 19th-Century Engineering Feat That Paved the Way for Today’s Screw Pile Innovations
- Jonathan Lyons
- May 13
- 2 min read
Updated: May 20
When you think of cutting-edge construction, you might not immediately picture a 19th-century lighthouse off the coast of Ireland. But the Spit Bank Lighthouse, completed in 1853, is more than a historical landmark—it’s a symbol of bold engineering that changed the foundation game forever.
At the heart of this marvel is an innovation we use every day at Xtreme Post: screw pile foundations.
Built on a Revolutionary Idea
In the mid-1800s, lighthouses were essential for maritime safety but notoriously difficult to build in offshore or marshy environments. Traditional foundations were too unstable, expensive, or impossible to install in silt or soft seabeds.
Enter Alexander Mitchell, a blind Irish engineer and inventor who defied expectations in more ways than one.
Mitchell developed the screw pile—a cast-iron shaft with a helix (screw-like blade) at its base that could be rotated deep into soft ground, creating a stable, load-bearing foundation. His idea was revolutionary: instead of displacing soil, screw piles gripped it.
The Spit Bank Lighthouse, situated in the challenging silty waters of Cork Harbour, became one of Mitchell’s greatest success stories.
Why Screw Piles Were the Smart Solution—Even Back Then
Mitchell's screw piles provided several critical advantages, many of which still apply today:
Minimal Disruption: No need to excavate or pour concrete in a marine environment.
Superior Grip in Soft Soils: The helical design allowed piles to anchor firmly in silty seabeds where other foundations failed.
Speed of Installation: Crews could install screw piles quickly, reducing exposure to dangerous tides and weather.
Durability: Over 170 years later, Spit Bank Lighthouse still stands—proof of screw piles’ long-term resilience.
The Legacy Lives On: How Spit Bank Shaped Modern Screw Piles
Today’s screw piles are more advanced—made from high-tensile steel, engineered for specific load capacities, and installed using hydraulic equipment—but the core principle is unchanged. We owe the fundamental concept of helical anchoring to Mitchell and the bold team behind the Spit Bank Lighthouse.
Modern screw pile systems, like those used by Xtreme Post PEI & NS, benefit from:
Precision engineering for variable loads
Corrosion-resistant coatings
Environmentally sensitive applications for wetlands, coastlines, and heritage areas
Modular design for relocation and reuse
The adaptability and sustainability of screw piles make them essential for today’s construction challenges—from remote cabins to solar farms to marine infrastructure. And it all started with a lighthouse.
From Ireland to Atlantic Canada
The Atlantic provinces share many of the same construction challenges as 19th-century Ireland: unstable soils, coastal erosion, remote access, and strict environmental regulations. Screw piles, with their proven track record and modern refinements, are the ideal solution for:
Shoreline developments
Floating docks and marine infrastructure
Off-grid tourism cabins
Lighthouse and heritage site restorations
By recognizing the innovation of the past, we’re better equipped to build for the future.
Want to Build on a Smarter Foundation?
At Xtreme Post PEI & NS, we’re proud to be part of an industry with roots as deep—and as smart—as the screw piles that hold up structures like Spit Bank Lighthouse.
Whether you're building a deck, a dream home, or an eco-retreat, you can trust the same technology that’s stood strong for over a century and a half.
Contact us today to talk about how screw piles can make your next project faster, cleaner, and more sustainable.
