When were the first helix supported deep foundations installed?
A – 1950 on a Virginia high voltage line.
B – 1955 On a New Jersey outfall pipeline
C – 1960 under a man in a barrel about to go over Niagara Falls
D – None of the above
The answer is “None of the above”. It is amazing, but the helical pier was invented by an Englishman, Alexander Mitchell. It was first used under a lighthouse in 1838 in the Thames River. The lighthouse was the Maplin Sands Lighthouse.
The foundation technology in the early 19th century was mainly stacking large stone blocks on good bearing soil to support structures. This technology did not work in the deep mud bottom of the Thames River, and the Chesapeake Bay, among other areas. So hoow were the helical piers manufactured and screwed into the soil underwater? The piles and helices were constructed out of cast iron. The shaft was 8 to 12″ diameter and there was one 24″ to 36″ diameter helix on the bottom. Barges were positioned around the pier shaft and horses or mules were attached to the pile shaft with arms coming off of the pile. The animals walked clockwise around the pier screwing it in to the soil below the water to the correct bearing depth.
In 1966, it was determined that the Hooper Strait Lighthouse was no longer needed in the Chesapeake Bay and it was moved to the Chesapeake Maritime Museum in St Michaels, MD. The Hooper Strait Lighthouse was built in the Chesapeake Bay on helical piers in 1879. The helical pier technology was already 43 years old.
When I entered the helical pier and anchor business in 1989 it was still not a widely known or frequently used deep foundation option. Convincing engineers that this slender shaft and plates will support their building/wall was not easy. The Mitchell story opened many eyes to the opportunities, and the A B Chance engineers did a great job supporting my sales efforts.
When I started as a A B Chance Territory Sales Manager in 1989, the helical pier was more then 150 years old. By 1989, the helical pier was hot dip galvanized for corrosion protection, had a slender high strength steel shaft, and had multiple helices. One of the more recent developments has been the use of large diameter pipe piles with large diameter helices– this results in higher capacities. The brackets also have evolved, so that they are now well designed and much easier to install for many applications. Additionally, the hydraulic drive heads and torque indicators are now in the 21st century (remember the shear pin torque indicator). I will say they worked well but you spent a lot of downtime changing the pins.
Indeed we have come a long way since those days. We have and will continue to find the best way to deal with your projects. We welcome innovative ideas. The future is open!
Office – 717-677-4835 Cell – 267-398-1872 WalterSmithDanbro@gmail.com