Lignum Vitae Bearings Anglo-Irish writer and satirist Jonathan Swift once said, “Everything old is new again.” That comment may well apply to lignum vitae, widely accepted as the world’s hardest wood and used for making self-lubricating bearings for the marine sector.
Valves & Pipes JA Moody, based in Malvern, Pennsylvania, has been producing valves for over five decades. The company says it’s positioned itself as a “trusted partner in providing innovative fluid control solutions to the U.S. Navy.”
Nearly two decades ago, Moody introduced the Vanessa Triple Offset Valve to the U.S. Navy, a vital product for severe service applications. Today, it’s once again leading the way by bringing Curtiss-Wright’s groundbreaking Dilating Disk Valve (DDV) to the maritime industry.
“The DDV is revolutionizing fluid control systems with its innovative design, offering unparalleled efficiency, weight reduction and cost savings,” the company says. “Built to meet MIL-DTL-32632 standards, the DDV’s rotary petal mechanism ensures superior flow efficiency, eliminating turbulence and minimizing energy consumption.”
Adds Moody’s CEO, Lisa Smith, “When compared to traditional globe valves, the DDV significantly reduces size, weight, noise and operational torque, making it the ideal choice for naval applications and shipbuilders looking to optimize system performance while cutting costs.”
With its plug-and-play capability, the DDV allows for seamless retrofits while its compact, durable design contributes to stealthier, more agile and energy- efficient operations. Offering potential energy savings of over 50 percent, the DDV is poised to set a new standard in fluid-handling technology.
Technology has also infiltrated piping systems, which are the veins that keep vital fluids flowing in ships. Recently, the Swedish Maritime Administration decided to replace the steel pipes in the jet thrusters of the Oden, the world’s largest diesel-electric icebreaker, due to corrosion issues. A complete solution for the task was provided by GF Piping Systems, which carried out extensive engineering services to enable a cost-efficient retrofit with 200 meters of DN1000 thermoplastic piping components, 100 electrofusion fittings and couplers made of PE100.
The thermoplastic pipes are corrosion-proof and therefore have a longer expected service life compared to metal while smooth inner surfaces allow the same flow volume as metal pipes in larger dimensions.
“This project perfectly encapsulates our vision for the marine sector,” notes Staffan Magnuson, Sales Manager, Marine. “We replaced an aging steel piping system with a corrosion-free thermoplastic alternative, and we were able to maximize the performance and longevity of the system thanks to our Specialized Solutions program. In addition, this project was special for us as it involved the largest pipe dimensions we’ve ever supplied for a vessel.”
As one of the most powerful non-nuclear vessels of its type, the Oden is active throughout the Baltic Sea during winter. For the rest of the year, it serves as a research platform for Swedish polar expeditions in the Arctic. To meet high operational demands, it was designed to be highly maneuverable and to use jet thrusters to spray high-pressure water onto the ice to reduce friction at the bow, thus increasing its energy efficiency.
THE REPORT | SEP 2025 | ISSUE 113 | 97
The first bearing successfully made of lignum vitae was patented by John Penn in 1854. Penn, a marine engineer, introduced water- lubricated lignum vitae bearings when the industry went from sailing vessels to screw and propeller vessels. There was no bearing to support the shaft, and after trying various things, lignum vitae was put into a stern tube and worked, says Bob Shortridge, President, Lignum Vitae Norh America.
“It became a standard of the industry all the way up to World War II,” he adds, speaking from a Great Lakes’ shipyard where he was working on a freighter. Lignum vitae bearings were used exclusively in the U.S. fleet to prevent the threat of losing a rubber seal and losing oil and, therefore, propulsion.
With the global industry looking to be more environmentally friendly, Shortridge sees a huge market for his products unfolding. Being asked to provide an all-natural, water- lubricated bearing “feels like things are returning back to full circle.”
With lead and asbestos all taboo now, everyone is looking for something reliable, long-lasting and environmentally correct. It must be less polluting but more robust for monstrous pieces of equipment.
“We’ve done an aircraft carrier twice, and this is the third Great Lakes carrier we’ve worked on,” he adds. “Life expectancy of the bearings depends on the machine but is generally 10 to 20 years.”
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