History of the Screw Pile

Many consider screw piles the most significant development in geotechnical foundation engineering.  Also known as helical piles or helical piers, screw piles are end-bearing, deep foundation solutions for securing wooden or steel shafts into the ground. Because one end of the post is a helix, similar to a corkscrew, when torque is applied, the helix gradually penetrates the ground until it is securely anchored into place. 

This ‘invention’ of screw piles is widely attributed to Irish engineer Alexander Mitchell. However, while Mitchell refined this technology, screw piles have been used to strengthen structural foundations throughout ancient and modern history.

Prehistoric Uses
Archeologists have found that screw piles were used during Neolithic times (12 000+ years ago) by Swiss Lake-Dwellers.  Presumably wanting protection from the elements, wild animals and hostile enemies, they used rudimentary wooden screw piles to build their homes into lake beds. Screw piles secured the foundation of their buildings despite the instability of a lake bed and made it possible for them to achieve the higher elevation they needed. The remains of some of these pile-dwelling villages have been identified as UNESCO World Heritage Sites.

Early Bridges
In 55 A.D. Julius Caesar and 40,000 of his soldiers built a bridge across the River Rhine in just ten days using wooden screw piles “as long as the river was deep”.  These posts were driven into the riverbed at an angle to accommodate the flow of water and strengthen the foundation of the bridge.

Timber piles were also used to construct the first bridge across the River Thames in 60 A.D. 

The Construction of Venice
The floating city of Venice was built on 118 small islands in the middle of the Venetian Lagoon at the head of the Adriatic Sea in Northern Italy around 400 A.D. To shore up the islands, hundreds of canals were built, their banks reinforced with wood pilings that penetrated the soft silt and dirt to a portion of the ground that was hard clay. They used similar pilings as foundations for buildings, placing them close together and then cutting off the tops to support solid platforms for the foundations of buildings.

For centuries after these innovative engineering feats, screw piles continued to be used for bridges, fortifications, cathedrals and other heavy structures, many of which remain standing today.

The Marine Era (1836-1875)

Alexander Mitchell revolutionized the use of screw piles in marine environments by inventing a cast or wrought-iron application equipped with helix-shaped blades that screwed into the earth. This made it possible to penetrate even deeper below damaged or challenging soil conditions and increased the stability of structures in coastal and deep sea environments.

Mitchell’s improvement elevated the popularity of helical foundations worldwide. It also enabled many large-scale structures when most construction projects were performed mainly by hand. During this period, screw piles were used to build solid foundations in challenging marine environments, including:

• river moorings for ships
• lighthouses
• piers
• water locks
• bridges
• boardwalks

Some of these structures are still standing, a testament to ingenuity, materials and craftsmanship.

1878-1931 – The Agriculture Era
With developments in irrigation, farming, plant and soil science, screw piles were used in many agricultural applications in the late 19th and early 20th centuries. Some applications included securing fence posts, shelters and buildings to protect valuable crops, livestock or farm equipment from high winds, heavy rain and other severe weather conditions. 1920-1980 – The Utilities Era

As infrastructure projects grew across North America, screw piles were used in an increasing number of utilities applications such as large dams, highway systems, power plants, aqueducts and cross-continental electrical transmission projects. 

1985-2009 – The Construction Era
During the North American construction and housing boom, screw piles supported small and large-scale engineering structures, particularly in scenarios requiring a deep foundation. With access to excavators equipped with high torque hydraulic motors, screw piles were used more frequently in the construction industry. 

Evolution of Screw Piles: Screw Anchors
Screw piles are now recognized as a preferred option for many different types of infrastructure projects.  However, as with all geotechnology, they have evolved to suit changing needs of diverse applications. In the utility transmissions industry, screw piles that support loads like buildings aren’t well-suited to poles, towers, lattices, turbines, etc.. We require a grounding solution that prevents horizontal movement along a structure.

As a result, we use screw anchors. With this grounding solution, the screw is anchored into the earth and a wire or pipe is attached to the anchor.  When force is exerted on the structure as a result of weather, geography, impact, etc. the wire or pipe ensures that it stays upright. This technology was inspired by the work of Albert Bishop Chance (1873 – 1949) who found that poles anchored with piles attached to wires could be efficiently re-anchored in coastal ice storms. Over the last several decades, Chance’s idea has undergone significant innovation, resulting in the power installed screw anchor solutions that quite literally support the utilities transmission industry.

ORBIS Screw Anchors
Our ground anchoring solutions feature screw anchors and are manufactured to exceed North American industry standards. ORBIS offers both galvanized and painted steel finishes as well as customized anchoring systems upon request. All of our screw anchors are interchangeable with all major brands. Given our ‘always in-stock’ philosophy, you can count on ORBIS to provide you with the best possible screw anchors when and where you need them.

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References

1. Lutenegger, A. J. “Historical Development of Iron Screw-Pile Foundations: 1836–1900”. The International Journal for the History of Engineering & Technology 8. 1 (2011): 108-128. Accessed August 26, 2022.
2. Corboud, P., & Gowen, M. “Protection of the World Heritage against archaeological research: the case of the prehistoric pile dwellings around the Alps registered at UNESCO. Annuaire d’archéologie suisse, 99 (2016): 157-164. Accessed August 26, 2022. 
3. Patowray, K. “Amusing Planet”. 4 January 2021
4. “History of Helical Piles”. Helical Anchors Inc., 25 June, 2020
5. Ceccato, F., Simonini, P., & Lionello, A. “Long-term mechanical behavior of wooden pile foundation in Venice.” 2013
6. “How Venice Was Built”. LivItalyTourns, 19 July, 2017
7. Robinson, A. “Alexander Mitchell | Inventor of the Screw-Pile Lighthouse.” Coast Monkey, 13 Apr. 2021
8. “Historical and Modern Applications of Helical Piles. eBrary. Accessed on August 26, 2022.
9. Clemence, S. P., and A. J. Lutenegger. “Industry survey of state of practice for helical piles and tiebacks.” DFI Journal-The Journal of the Deep Foundations Institute 9.1 (2015): 21-41.
10. “Ground Anchors – The History.” AARSLEF, 30 Mar. 2017