Apron. The area along the waterfront edge of the pier or wharf.

(a) A slab of reinforced concrete or a heavy timber and plank platform covering the top of a group of piles for the purpose of typing them together and transmitting to them as a group the superimposed load.

(b) A metal plate placed across the top of a steel tube pile to distribute the load from the steel tube to the concrete.

Bearing pile. A column of wood, metal or concrete or a combination of two or more of these materials, driven, jacked, or sunk with a water jet, into the earth to transmit and distribute loads to strata below the surface.

Bulwark. The side of a ship above the upper deck.

Caisson pile. A concrete pile case in an outer casing consisting of a series of telescoping steel tubes, the top section being the largest and usually 20 inches or more in diameter.

Coaming. The raised frame, as around a hatchway in the deck, to keep out water.

Composite pile. A pile which consists of a concrete pile superimposed on a wood pile.

• Pedestal type concrete pile means a cast-in-place pile with an enlarged (mushroom) base or foot.

• Tapered type concrete pile means a cast-in-place pile cast in a tapered metal shell.

Driving cap. A device placed on the top of a pile to prevent its breakage or injury during the driving operation.

H-pile. A pile formed of a structural steel column of "H" section.

Jacob's ladder. A marine ladder of rope or chain with wooden or metal rungs.

Pile driver. A device or piece of equipment used in driving piles.

Precast concrete pile. A pile which is cast in a form above ground.

Pretest or jack pile. A steel cylinder pile driven in section beneath an existing building and filled with concrete.

Rail. For the purpose of WAC 296-155-630, means a light structure serving as a guard at the outer edge of a ship's deck.

Sheet piling. A continuous vertical barricade consisting of squared timbers driven edge to edge, either square edged or tongued and grooved, or of a series of inter- locking steel shapes, to form a temporary wall about an excavation, and shored and braced as necessary.

Steel-tube. A concrete-filled steel cylinder, consisting of an open or closed-end steel tube or cylinder.

Wood pile. A pile which is formed from the trunk of a tree or dimension timbers.