The Living Bridge crossing over a tidal estuary, is a living laboratory for researchers, engineers, future engineers and the general public. This bridge is instrumented with sensors that capture structural performance, traffic patterns, environmental conditions, the behavior of innovative bridge design elements and enable and promote community engagement. The information collected with these sensors is shared with researchers, bridge designers and the bridge owner, but also, where appropriate, with K-12 classrooms and the public. Aesthetic lighting and social media is used to communicate relevant information from the bridge and environmental sensors, such as weather, tides and traffic to the local community.
The bridge sensor network, information communication system and aesthetic lighting are powered by a tidal turbine (vertical-axis cross flow). A custom floating platform with nominal dimensions 50 ft x 20 ft (15 m x 6 m) was designed, fabricated and deployed. It uses 42” diameter HDPE pontoons for buoyancy and a galvanized structural steel frame for structural strength. Turbines are deployed through a moon pool via a turbine deployment mechanism. Axial-flow and cross-flow marine hydrokinetic (MHK) turbines with diameters up to approximately 10 ft (3 m) can be deployed. The TDP was first deployed at Memorial Bridge under the NSF-funded “Living Bridge Project” with a 3.2m diameter commercial cross-flow turbine. The mooring system at Memorial Bridge consists of robust custom-designed pile guides which attach to 22-ft tall vertical guide posts on Pier #2, allowing the platform to travel vertically with changing water levels. Various instrumentation components including flow measurement
instrumentation, wave measurement instrumentation, and a mobile data acquisition system was acquired to complement the instrumentation already available through the Living Bridge Project. The TPM has a universal mounting bracket with a defined bolt pattern, to which turbine developers can mount their turbine.
This bridge has the capability to advance all aspects of community engagement with infrastructure, clean energy innovation in tidal energy conversion, energy storage, structural and environmental impact, and social perception of our engineered environment. The proposed sensing network, including structural response sensors, underwater instrumentation and cameras, and weather stations, will allow for a complete system-based evaluation, including the impact of the tidal turbine. This “smart bridge” provides a platform for continued innovation of sensor, communication, and energy technologies.
The University of New Hampshire Center for Ocean Renewable Energy (UNH-CORE) utilized U.S. Department of Energy (DOE) funding for ocean renewable energy infrastructure to design and fabricate a hydrokinetic (tidal) Turbine Deployment Platform. Other project partners include Northeast Integration (NEI), New Energy Corporation Inc. (NECI), Bridge Diagnostics (BDI), MacArtney, Airmar, Seapoint Sensors, and Lite Enterprises.
Attached to The “Living” Memorial Bridge on the Piscataqua River, between Portsmouth, NH and Kittery, ME, U.S.
The project was granted funding by the National Science Foundation (NSF) on August 15, 2014, specifically to researchers at the University of New Hampshire. On February 1, 2016, a preliminary analysis was performed to design the Instrumentation Plan and later that year (December 6) the vertical guide posts (for mooring) to the tidal turbine structure were installed at the Memorial Bridge. On March 1, 2017 the structural sensors were installed, and a few months later (June 22) the turbine platform was deployed and is equipped with instrumentation to measure estuarine parameters in the Piscataqua. On October 1, 2017, the structural sensor was installed on the vertical guide posts and later that month (October 27) a load test was conducted. The turbine was first deployed in the summer of 2018, and has since been operated successfully in both off-grid (25 kW load bank) and grid-connected configurations (480V bridge grid).
Key Environmental Issues
The project then went through an Environmental Assessment under NEPA in 2014, including a Biological Evaluation, through DOE Golden office, and eventually a finding of “Not Likely To Adversely Affect” (marine fauna, flora) was obtained. The test site is permitted under the US Army Corps of Engineers.
Papers, Reports, Research Studies
- Structural Health Monitoring and Design Verification of Tidal Turbine Support Structure
- Tidal Energy Conversion at an Estuarine Bridge - Integration of a Tidal Turbine into the Living Bridge Project
- Local flow and turbulence at a tidal energy conversion installation near a pier of an estuarine bridge
- Resource Evaluation and Energy Production Estimate for a Tidal Energy Conversion Installation using Acoustic Flow Measurements
- The Living Bridge Project: Local Flow Conditions at a Tidal Energy Conversion Installations at an Estuarine Bridge
- Infrastructure Enhancements Final Report
- Research Progress Report (July-Sept 2016)