This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
When the piles have been driven, they are sawed off to bring the top of them to the same elevation so that they will have an even bearing surface. When the tops of the piles are above water, this sawing is usually done by hand; and when under water, by machinery. The usual method of cutting piles off under water is by means of a circular saw on a vertical shaft which is supported on a special frame, the saw being operated by the engine used in driving the piles.
Fig. 53. Foundation on Wooden Piles.