Concrete Planking Boat Ramp Installationby K.K. Lowell
The construction of a boat ramp in a body of water is easier using pre-stressed concrete planks. Made just for the purpose, these planks offer ease of use, strength, correct sizing and rapid ramp construction. They also eliminate the need for cofferdams and pumps.
The area surrounding the proposed ramp should be large enough for vehicle and trailer parking and fairly flat, with an area for the ramp itself that is sloping into the water. The water should be of sufficient depth that the end of the ramp will be under at least four feet of water during low-water periods.
The best time to build a boat ramp is during the low-water period of summer. More of the bank will be exposed during this time, allowing access to much more of the ramp site. The ramp area should be graded to a slope of 12 to 15 percent. Whenever possible, the entire ramp should be one grade, but if necessary, a slight change in grade can be made in the ramp. Ensure that the trailer will not hit the ramp where the grade changes, and make any necessary grade changes as far up on the shore end of the ramp as possible. The bed for the concrete planks should be level and about six feet wider than the ramp planks. Place 3/4-inch crushed stone on either side of the ramp to eliminate the risk of a trailer backing up over the edge of a plank and becoming stuck.
Constructing the Ramp
Heavy equipment will be required to lift and place the concrete planks. Planks are available in various widths, up to 26 feet from some sources, and are very heavy. Start from the top of the ramp and place the planks down the ramp and into the water. Be certain to have adequate planking under water to accommodate any boat that might be launched. If the planks do not interlock with each other, place 3/4-inch crushed stone between the planks. Larger crushed stone, in the four- to six-inch range, should be used to extend and protect the underwater end of the ramp. This will prevent erosion caused by outboard motors during loading of boats.
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