The concept of a pile for construction is credited to a Neolithic tribe called the "Swiss Lake Dwellers" who lived in what is now Switzerland about 6,000 years ago. They used piling, not for supporting heavy loads as we do today, but for elevation to protect them from wildlife.
The Romans often used piles, and built many structures, including buildings, homes, bridges, roads and viaducts on piling. The Romans built the first bridge across the Tiber River in Rome on timber piles in B.C. 1620. Homes in the cities of Venice and Ravenna were built on piles from B.C. 100 to A.D. 400. The Romans also built the first bridge across the Thames River in London in A.D. 60 on timber piling. The still excellent condition of piles used for the Circus in Arles (France), built in A.D. 148 on wetlands, can be seen in the museum at the site.
The modern age of wood preserving began in England in 1832 with the concept of pressure injecting chemicals into wood. In the U.S. the first treating plant was built in 1848 for treating railroad ties.
The Erie Canal locks in New York, completed in 1825, were constructed with one- and two-ton blocks on the floor of the locks, supported on a system of 6-foot (1.8 meter) timber piles. Each lock was supported on 700 piles, arranged in rows of 15 to 20 piles across the width and two feet apart.
Original drawings prepared in 1896 of the San Francisco Ferry Building show it resting on 5,000 redwood piles, 14 inches in diameter which were driven down 80 feet into the San Francisco Bay mud. Investigation of the piles in 1981 showed the piles were in perfect condition.
Today wood piling is a mainstay of foundation systems. Engineers and contractors depend on wood piling to perform its intended function in all kinds of structures, including manufacturing plants, processing facilities, and commercial buildings. For example, thousands of pressure-treated wood pilings form the foundation of the new construction projects for JFK Airport in New York and Dulles Airport in Northern Virginia. The city of New Orleans, Louisiana, is built on timber piles. Driven piles have a long history in advancing civilization in all parts of the world.
Timber Pile Points
The potential problems associated with driving timber piles are splitting and brooming of the pile tip and driving end, or the splitting or bowing of the pile body and breaking of the pile during driving. To avoid some of these problems, protective attachments at the pile tip and pile head can be used.
The trend toward heavier hammers and heavier design loading may mean that timber will be subjected to damaging blows when the pile reaches obstructions or end bearing. As a result, timber piles can be protected by a metal boot or point. The point shown in the picture covers the entire pile tip without the need for trimming the pile tip. Also shown is another type of point protection attachment, however requires minor trimming of the pile tip.
Tip protection by a boot or shaped point are recommended with banding near the top to alleviate splitting. The boot is preferred as it attaches quickly having to "point" the actual timber pile and utilizes the full area of the wood for load carrying. Heavy steel banding, perhaps 1-1/4 in. wide and .031 in. thick at 1.5 to 2 ft. below the top of the pile is generally helpful.
Attachment of points (as opposed to a "boot") for timber piles require that the tip be accurately cut to shape. Otherwise the point has limited value as bearing is uneven. If not straight, it may deflect the pile.
NOTE: The American Wood Protection Association (AWPA) recommends banding timber piles with heavy metal strapping at the driving end prior to driving to prevent the start of splitting.
Both, boots as well as points, are available in several sizes. As a result, a size can generally be selected that can be placed on the pile with little "hand-axe" cutting of the pile tip.