- Bridge Specs: Tower Height = 18′: Span = 100’: Travel Width =5’: Deck = Pultruded Fiberglass: Mainline = 1” galvanized bridge rope: Suspender Size = 7/16” IWRC
- Services Performed: Design/Engineering, Fabrication, Installation.
Sahale’s Rock Springs Park Suspension Bridge is located in Gwinnett County Georgia near the County Seat of Lawrenceville. Gwinnett County is a crossroads of sorts and has an interesting and colorful history to which the new Park and Sahale Bridge are recent additions. The County was created in 1818, and named after Button Gwinnett, a signer of the Declaration of Independence who later served as Georgia Governor before meeting an untimely end in a duel. The first settlers arrived in the area in the late 1700’s after the Cherokee ceded lands to the US Government in 1790, and the town of Lawrenceville was established in 1820. Other former occupants of the area, the Creek Indians, resisted the pioneer advance and hostilities eventually erupted in the late 1830’s in the form of the Creek Indian War, in which Lawrenceville contributed two volunteer companies that suffered significant losses. Later, during the Civil War, the County was overrun in 1864 by Union soldiers when Sherman captured Atlanta.
Much of the wealth of the County was lost during Reconstruction, with the disintegration of the large plantations following the Civil War. Nonetheless, Gwinnett County grew under the new economic model and steadily gained in population through the 20th Century, and is currently second only to Atlanta’s Fulton County. Growth and development fueled a strong Park movement in the County with the Gwinnett County Parks and Recreation Department now operating 32 parks and facilities and having one of the most ambitious green-space programs in the nation with over 8,000 + acres of park land. Awarded the prestigious Gold Medal Award (Class 1) by the National Recreation and Park Association in 2008, Gwinnett County Parks wanted an iconic cable bridge as the centerpiece of a two mile trail in the new 113-acre Rock Springs Park.
Enter Sahale. The Gwinnett County Parks Department reached out to the firm for design and cost proposals for supply of an iconic bridge. Led by Albert Highberger (PE), Brandon McGinnis (Lead Designer), and Carroll Vogel (Master Builder), Sahale submitted design and cost proposals that were ultimately selected to be included in the larger Park construction contract under ‘Sahale or Equal’ language. Sahale then consolidated the costs for bridge design and fabrication into a single bridge supply quote for General Contractors bidding on the Park Construction Solicitation. Additionally, a price for bridge installation option was provided, also consistent with the original quote to Gwinnett County Parks.
By the time the County was ready to award the Park Construction Project, Sahale was on site installing the nearby Lullwater Suspension Bridge at Emory University. Officials from Gwinnett County were able to visit the Lullwater project and observe firsthand our installation process, and gain insight regarding design features for their own bridge. Sahale began issuing purchase orders for material in November 2008, embarked on fabrication (led by Steve Howell) in December 2008, and shipped the bridge kit to Gwinnett County in early February 2009.
Aaron Nelson shipped out to Georgia from Seattle in time to meet the incoming bridge, and led a field crew that included Ken Gilman, Austin Thompson, and Steve Howell. Four full weeks were spent preparing abutments and anchors, owing to problems driving helical piles into soils that proved far more stubborn than the Geotechnical Investigation had indicated. We were stubborn, too: getting refusal for our square shaft helical piles at 7-10 feet, Sahale redesigned excavation and forming plans and put those changes into immediate effect. North abutments and anchors were poured and complete on March 7; the South abutments and anchors were ready March 11.
Given prepared abutments and anchors, a Sahale field crew can generally be expected to move fast, and did. Nelson’s team had towers up on March 17, superstructure installed by March 23, and decking, railing, fencing, and tuning were complete by the end of the month, well in advance of the Grand Opening of the Park on May 16, 2009. The bridge is a credit to the resourcefulness of the design and installation teams, and a fitting way to tie together the two-mile trail system winding through the park’s wooded setting.
Sections of this text courtesy of Carroll Vogel, 1/15/2010