Pile driver

The weight is raised by some motive power (which may include hydraulics, steam, diesel, electrical motor, or manual labor).

However, there is evidence that a comparable device was used in the construction of Crannogs at Oakbank and Loch Tay in Scotland as early as 5000 years ago.

Modern piledriving equipment variously uses hydraulics, steam, diesel, or electric power to raise the weight and guide the pile.

Piledriving is started by raising the weight; usually a cable from the crane holding the pile driver — This draws air into the cylinder.

The rising weight draws in fresh air, and the cycle continues until the fuel is depleted or is halted by the crew.

The compressed air exerts a pre-load force to hold the impact block firmly against the drive cap and pile.

At the bottom of the compression stroke, the piston strikes the impact block, atomizing the fuel and starting the pile on its downward movement.

In the instant after the piston strikes, the atomized fuel ignites, and the resulting explosion exerts a greater force on the already moving pile, driving it further into the ground.

[12] The reaction-based machines operate at only 69 dB at 23 ft allowing for installation and extraction of piles in close proximity to sensitive areas where traditional methods may threaten the stability of existing structures.

Such equipment and methods are specified in portions of the internal drainage system in the New Orleans area after Hurricane Katrina, as well as projects where noise, vibration and access are a concern.

The vibration rate chosen is influenced by soil conditions and other factors, such as power requirements and equipment cost.