Specifications
Floating Docks, Bridges and Ramps
1. Dead Load Design
Dead Load is defined as the weight of the entire dock and utilities including all electric, water, sewage, fire, cleats, etc. Pipes carrying liquids shall be assumed to be full when calculating dead load
Dead Load freeboard shall be 17” to 20”.
Affordable Boat Docks shall list the freeboard of each dock unit on the submittal drawings. Actual dead load freeboard shall be no more than +/-1 inch of the freeboard listed on the drawings with the following exceptions.
The outer ends of finger docks shall be either level with or may be up to 2 inches higher than the main walk where they attach. The outer ends of the finger docks shall also have no more than a half-inch drop across the end per 3’ width.
The mainwalk dock under bridges/Gangways may be up to 2” to 3” higher than the average mainwalk freeboard listed on the submittal drawings.
Mainwalk shall not slope lengthwise or crossways more than 1 inch in 8 foot.
For cantilever docks both ends shall be a maximum of +/- one inch from the average freeboard of the dock.
2. Vertical Live Load
All dock walking surfaces shall have adequate floatation under them to support all dead loads plus a minimum of 30 pounds per square foot live load
The dock and supporting frame shall support a 400lb. Concentrated load on any one square foot area.
Additional flotation shall be provided under the docks at bridges and ramps so as to prevent loss of freeboard (defined by NLMS as 25% of total freeboard) under the bottom of bridge or ramps under normal loading conditions.
Under dead a full live load, there shall be a minimum freeboard of 6 inches
When a 400-pound load is applied in the center of a finger dock or a cantilever dock, 2 foot from the outer end, there shall be no more than 4 inches loss of freeboard at the end of the dock.
If docks cantilever off shore, there shall be no more than 4 inches of loss of freeboard when a 400-pound load is applied in the junction of the bridge or ramp and the first dock section.
When a 200 pond load is applied to one outer corner of a finger or a cantilever dock, there shall be no more than 2” of difference in freeboard across the end of a 3 foot wide finger, and proportionally more on wider fingers.
3. Horizontal Live Load Design
A. Wind Loads
Wind loads shall be 15 pounds per square foot (77miles per hour) approaching from any and all directions. Loads shall be calculated perpendicular to diagonally opposite corners of the pier, perpendicular to the main walk and perpendicular to the dock fingers.
Wind loads shall be applied to the pier continuously with out any deductions from walkway, fingers or open areas between boats.
Wind loads shall be applied to a vertical plane from the water surface up to the average high profile of all boats expected to use dock. Typical profiles for marinas are as follows:
Finger and/or
Maximum boat length, Profile Height
20’, 7’
24’, 7’
28’, 7.5’
For launch and boarding docks use a 2’ profile height.
Wind loads shall be applied 100% to the exposed boats and an additional 15% to each shielded boat behind the exposed boat.
B. Wave Loads
Docks shall be designed to withstand 1-foot continuous waves and occasional waves up to 3’ four a duration of four hours.
C. Combined Loads
Anchorage design shall be adequate to withstand wind and wave loads which shall be applied cumulatively.
D. Ice Loads
The structures, floats and anchorage system shall be designed to withstand the forces of NON-moving ice without damage.
E. Impact Loads
All mainwalk docks, finger docks and connections shall be designed to resist the impact of a boat, the length of the finger, striking the edge of the finger dock, at the outer end, at a maximum angle of 10 degrees to the dock centerline at a velocity of 3 feet per second for 1 second deceleration. Boat weights for various boat lengths shall be assumed as follows:
20 foot 4,000 pounds
24 foot 8,000 pounds
28 foot 13,000 pounds