Carbon stairs make boarding a sailing yacht a breeze
Traversing from ship to shore can be treacherous for passengers, especially in rough conditions. GMT Composites Inc. (Bristol, R.I.) began to address this issue with practical composite gangways and boarding ladders in 1994 and has since built hundreds. Lightweight but strong — typically carbon fiber — the boarding systems are easy to move and stow, and they eliminate deck rash (damage) caused by heavier, all-metal boarding systems.
Sea Stairs is GMT’s most versatile boarding option. Custom-designed for the customer’s vessel, each can be deployed perpendicular or parallel to the vessel, with optional boarding platforms on the top and bottom. GMT’s sales director, Jonathan Craig, explains that the stair elements are fabricated with intermediate-modulus carbon fiber/epoxy prepreg supplied by Mitsubishi Chemical Carbon Fiber & Composites Inc. (formerly Newport Adhesives and Composites, Irvine, Calif.). The stair rails, to which the treads are fastened, are hollow, square tubes, and the stair treads are thin, foam-cored box structures, both cured out of autoclave. The front of each tread fastens to the top rail, and the back of each tread connects to the lower rail, so the stairs can articulate as the vessel rises or falls, to keep the treads level. GMT uses polished stainless steel fasteners and other hardware that does not require intermediate protection to avoid galvanic reaction with the carbon fiber. The stairs can be designed to reach to the dock, the water, or both, with handrails of either stainless steel or rope supported by stainless stanchions.
Sea Stairs have been made for several large power yachts, and a custom-built Sea Stairs system was displayed at the 2013 Newport International Boat Show on a 70-ft/21.3m Empacher sailboat built by Brooklin Boat Yard (Brooklin, Maine), dubbed Sonny. The vessel also has a GMT carbon fiber mast and PowerFurl boom. Adds Craig, “In addition to her carbon rig, Sonny’s Sea Stairs highlight a significant product that shows how much easier and more secure it can make boarding a yacht — an increasingly important feature as we age.”
Read about another carbon fiber gangway online: Click on "Carbon fiber makes ship-to-shore crossings more stable," under "Editor's Picks," at top right).
Compared to legacy materials like steel, aluminum, iron and titanium, composites are still coming of age, and only just now are being better understood by design and manufacturing engineers. However, composites’ physical properties — combined with unbeatable light weight — make them undeniably attractive.
Yes, advanced forms are in development, but has the technology progressed enough to make the business case?
Commercial production of recycled carbon fiber currently outpaces applications for it, but materials characterization and new technology demonstrations promise to close the gap.