Boat & Yacht Design
Liferails: Keeping the Crew on Board
Boats need to have certain safety gear installed to be NMMA certified to ABYC standards, and one of the most obvious are liferails. These railings along the sides and foredeck of many boats give the crew something to grab as they make their way around while the boat is underway. They need to be built to certain dimensions to do their job properly, in the eyes of the ABYC.
Boat Building Standards:
Liferails
ABYC Standards--
- The periphery of weather decks intended to be occupied at boat speeds in excess of 5 mph shall be equipped with one or more of the following: liferails, deckrails, or lifelines, or a structure at least 24 inches (61 cm) above the weather deck, such as a coaming, gunwale, bulwark, or a handhold device or grabrail attached to the inboard structure.
- All handhold devices shall withstand a load of 400 lb. (182 kg), in any direction, at any point along their length without failure such that they no longer perform their intended purpose.
- Devices or grabrails that consist of piping or tubing supported by stanchions must have a diameter not less than 0.75” (1.9 cm) nor more than 1.5” (3.81 cm) for round tubing. For any other shape of tubing, they must have a minimum circumference of 2.35” (5.97 cm) and a maximum circumference of 4.7” (11.94 cm).
- The clearance between the adjacent surfaces and the railing shall not be less than 1.25” (3.18 cm), and the rail shall not rotate when subjected to a torque of 10 ft. lbs. (13.6 Nm), and the termination shall not include a closure angle of less than 45 degrees.
- Intermediate rails, lines wire mesh, or equivalent shall be installed wherever the space between rails, deck, or toe rails exceeds 24 inches (61.0 cm).
- If a handhold device consists of a solid strip of wood or other material without openings, secured or molded to the top of the cabin, deckhouse roof, or other surface it shall not be installed on surfaces with an angle greater than 45 degrees to the vertical.
- Such solid grabrails shall have a minimum height of 1 3/16” (3.02 cm) and shall be concave and well hollowed on the inboard side and shall have a minimum overall width of 1 5/8” (4.13 cm).