Community docks for St Johns River

The City of Jacksonville, Florida has the largest urban park system in the USA and, in order to enhance its dynamic network of outdoor community spaces, is adding numerous docks along the St Johns River for visiting boaters and water taxis.

The new Post Street location in the historic Riverside neighbourhood presented several engineering challenges that were easily overcome when the City selected an SF Marina floating concrete dock system.
The Post Street boat landing site not only contends with a fast-moving river current, but also strong southerly wave action. The location is also directly adjacent to underground utilities so the dock structure had to be rock-solid so as to remain in place if a hurricane were to hit the area. The City specified that it would need to withstand 120mph (193kpm) winds for two hours with 10ft (3m) storm surges.
Jacksonville-based Hal Jones Contractor installed the two-part 95ft (29m) long x 10ft (3m) wide SF1230 HD pontoon and three SF1224 32ft (10m) x 8ft (2.4m) fingers. The sections are joined together using SF Marina’s connector system that absorbs torsional tension and heavy loading. The array is designed to accommodate six vessels up to 50ft (15m) in length.
To secure the structure, the contractor drove eight 20in (51cm) steel piles over 40ft (12m) deep into the rocky river bottom. This safeguards against the array moving and damaging the utility lines. Custom guides allow the pontoons to rise and fall smoothly with water level changes.
The concrete pontoons were manufactured in SF Marina’s Norfolk, Virginia facility and trucked to Jacksonville.
www.sfmarina.com