The origin of screw piles and their evolution
The origin of screw piles and their evolution
The origin of screw piles is not new! Although they have greatly evolved, they have been used for nearly two centuries. When the first ones were invented, the screw piles revolutionized the construction world, and many construction sites still use them today. How did they come about and why are they so effective? Find out here!
A 19th century invention
In 1833, Irish engineer Alexander Mitchell first described his invention in an English engineering journal. The screw pile was born! Originally, screw piles were made of a steel shaft and a blade at one end. The whole assembly was buried in the ground for an in-depth screwing.
In 1836, they were used to build wharves for shipping vessels, and in 1848, the first screw-pile lighthouse was built at the northern entrance to the Thames River. The Maplin Sands Lighthouse was a major structure erected on 9 cast iron piles and screwed into the sandy soil at a depth of 27 feet. Solidly anchored and able to withstand the movements of the water’s floor, this lighthouse was a success.
Screw piles were recognized for their strength in lighthouse construction, and their use spread to Europe in the 1850’s. Mitchell’s team built the Walde Lighthouse on the beach at Calais in France.
In 1847, Mitchell adapted his technology to ocean wharf construction and led a project south of Arklow, Ireland. Because of the weather in the Atlantic Sea, the engineer modified his original plans and the dock was built from the shore instead of from the water. The team used a huge capstan (32 feet) to turn it by hand and screw in the piles. With this successful project, Mitchell extended the screw pile engineering to docks and bridges, some of which still exist.
The evolution of screw piles
This new technology spread throughout the world and evolved differently according to the particularities and needs of each country. The evolution of screw piles was marked as much by changes in their manufacturing as in their installation or use.
The USSR’s contribution
The different climatic conditions in the USSR forced the country to develop its own screw pile technology. The engineers aimed at rapidity of execution and simplicity of installation to carry out their work. Their theories were based on calculations, technical criteria and choice of materials that allowed the optimization of the installation of piles in various types of soils, especially during large-scale works in permafrost and coastal regions. In 1955, they established the first standard for this purpose and the installation of telecommunication structures proliferated in the USSR.
Between 1961 and 1964, Russian engineers established the first standard for the use of screw piles to support huge power line towers.
Use in North America
As early as 1838, screw piles were used for maritime construction in North America. The “Brandywine Shoal” lighthouse in Delaware was one of the first. Between 1850 and 1910, more than 100 other lighthouses were built on the coasts of Massachusetts, Florida, the Chesapeake Bay in Maryland and Virginia. Screw piles were also used to build homes on piles. The first one was built in Boston in 1900.
As alternatives to Mitchell’s designs, American engineers developed new configurations, and the piles became helical cylinders. In doing so, they reduced the amount of steel or cast iron needed to produce them. Several decades later, engineers in the 1950s and 1960s further improved efficiency by welding the helix to the pile shaft and changing the number of turns and diameter width to better support the loads.
Today's screw piles
The load-bearing and tensioning capacities of galvanized steel piles can now support loads of up to 500 tons. Resistant to weathering and rust, they have a lifespan of hundreds of years! Industrial, commercial, recreational and residential construction sites all use this technology. Engineers can find the most appropriate piles to install under existing structures, under ice, on uneven ground, in rock or in water.
In the 19th century, piles were screwed into the sea floor by hand and sometimes with ropes and capstans. Nowadays, this installation work is relatively simple, fast and safe. With mechanical equipment, it is possible to transport and screw the piles into the ground without damaging the soil.
Would you like to learn more? Our experts know screw piles like the back of their hand!
