C+S September 2020 Vol. 6 Issue 9 (web)

Stewardship Council® (FSC ® C117772) Certified indicative of their having been harvested from responsibly managed forests. They are fully aligned with the principles of environmentally sound construc- tion and “engineering with nature.” If you look at premium Ipe, also known as Brazilian Walnut, the marine lumber used in the Ponquoque Bridge restoration project, the sustainability aspects of this hardwood is evident. Ipe (Brazilian Walnut) Ipe has properties that made it the optimum material for the Ponquogue Bridge project. It is extremely strong, durable and dense – twice as dense as most woods and five times harder. Able to withstand heavy pressure, Ipe has a hardness measurement of upwards of 3,500 which is over 2.5 times the hardness of oak, placing it at the top of the Janka rating. It is also naturally resistant and without any chemical treat- ment, is impenetrable to insects, including termites. Ipe has proven to remain naturally resistant to insects and marine borers for 15 years which far exceeds any other wood’s ability. Its density also contributes to its water resistant, making it slip-resistant. This feature, along with its Class “A” Fire rating from the National Fire Protection Association (NFPA) helps reduce slip and fall and fire related risks and exposures. Unlike other wood specified for marine projects, Ipe requires minimal maintenance or the use of hazardous, toxic chemicals. Maintaining its warm red and brown hue requires cleaning with a wood cleaner and an annual UV protection coating. Because of its high density grain and natural oils, it is almost completely impervious to rotting, mold and fungus growth. With its low maintenance and lifespan of between 50 and 75 years, Ipe delivers a strong return on investment, far greater than other construction materials including composites, concrete, and softwoods. In addition to Ipe, another widely-specified hardwood used in marine projects is Greenheart (Sipiri). It too possesses outstanding strength and durability, is pest and marine borer resistant and immune to rot, mold, algae and fungi growth. It also holds a NFPA Class “A” Fire Rating. Among its specifications are: an air dried density (12 percent) of 970 kg/m3, bending strength (at 12 percent) of 240 N/mm 2 , modulus of elasticity (at 12 percent) of 24500 N/mm 2 , compression parallel to grain of 89.9 N/mm 2 and crushing strength (at 12 percent) of 98 N/mm 2 The Bridge Restoration Project Leading the Ponquogue Bridge project were the engineering design group of L.K. McLean Associates, P.C. (Brookhaven, NY) and the marine construction/engineering firm of Chesterfield Associates (Wes - thampton Beach, NY and Westport, ME). The project involved the reconstruction of the south side of the old bridge, and redesign of the north side as an additional 60 foot long fishing pier that encompassed flow-through grating to accommodate the rise and fall of storm tides and prevent future damage. The project began with the design, survey, and securing of environ- mental permits (i.e., NewYork State Department of Conservation, U.S. Army Corps of Engineers, and New York Department of State) for the partial demolition and reconstruction of the Old Ponquogue Bridge and piers. Twenty four pile bents were evaluated and rehabilitated across both the north and south piers. The actual restoration encompassed the

replacement or rehabilitation of existing timber pier piles and replace - ment of horizontal wales, longitudinal cross bracing, transverse cross bracing, riders, and stringers. The first phase of the project involved Chesterfield Associates’ col - laring of an estimated 48 of the wood pilings supporting the former bridge. The pier, which lies on the south side of the bridge and is used primarily by divers, juts out into the Shinnecock Bay and is longer than the northern pier which serves as a fishing pier and was shortened by an estimated 300 feet in the project. The project components included: a sustainable deck and handrail, new bulkheads, and recreational access ramps. Three truckloads of Americans with Disabilities Act (ADA) compliant Ipe lumber for the sustainable deck and handrail were pro- vided by Evergreen Forest Products, Inc. (Wading River, NY). Protecting the Ecosystem The use of Ipe marine lumber in key components of the restored Ponquogue Bridge, along with the project’s design, contributed to its eco-friendly status both from a protecting the water standpoint and the protection of the area’s marine ecosystem. The bridge’s pilings are home to anemones and serve as a nursery for young striped bass and black fish, as well as a habitat for tropical fish (e.g., scamp, snowy grouper, spotfin butterflyfish, roughtail stingray, etc.) that arrive via the Gulf Stream through the incoming tide of the Shinnecock Inlet. The bridge infrastructure also serves as a place for seasweeds, barnacles, inverts, sulfer and red beard sponges, and tunicates to attach to which, in turn, provide food and shelter for other marine organisms, small fish, crabs, mussels and shrimp. Helping to support this ecosystem with sus - tainable marine projects like the Ponquogue Bridge project featuring a wood like Ipe is why sustainable marine lumbers are gaining broader application and respect across the engineering and design community.

RICHARD ZIMMERMAN, JR. is Sales Manager at Evergreen Forest Products, Inc.


september 2020


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