Design of Bridge Control Systems

Evergreen Point Floating Bridge

On April 2nd, 2016, the Washington State Department of Transportation hosted the Grand Opening for the new Evergreen Point Floating Bridge, better known as the 520 Bridge. The new bridge replaces the former 520 Bridge as the longest floating bridge in the world. Spanning 7,710 feet, the 520 Bridge connects Medina to the Montlake district of Seattle across Lake Washington.

Systems Interface’s responsibility on the new 520 Floating Bridge was for the design, manufacturing, programming, and installation of the Bridge Control System (BCS). The BCS monitors more than 1,600 leak detection points across 77 concrete pontoons. It also monitors the medium voltage power stations and the Cathodic Protection system. Additionally, the BCS monitors and controls various lighting functions such as the interior lights in each pontoon, the under deck lighting, and the navigation lights.

Our control panels use Rockwell Automation ControlLogix® PLC systems with Panelview HMI terminals that utilize Rockwell Automation Stratix Managed Ethernet Switches to create a redundant Ethernet Protocol network. The panels are connected via a fiber-optic network that extends over 16,000 feet.

The complete connection of all the control panels represented a milestone for Systems Interface: it is the largest fiber-optic network built by SII to date. Dave Pettit, the Project Manager on this project, breathed a sigh of relief during testing as he watched all the panels successfully connect. Mr. Pettit logged the most hours on the project, coming in at more than 2,800 hours over four years. Systems Interface’s on-site UL-certified manufacturing shop logged nearly 2,000 hours on the project, with Jason Neal adding almost 700 hours by himself during the manufacturing process. Nearly 40 additional Systems Interface employees contributed to the 520 Floating Bridge project.

Systems Interface Inc has been a leading provider of industrial control systems for over 30 years. From its office and UL-508A/UL-698A certified manufacturing shop located in Bothell, Washington, Systems Interface has engineered and built thousands of control systems for a variety of industries including aerospace, maritime, and utilities and energy. In recent years, the company has experienced an increasing demand for complex drives and servo control systems.

“Systems Interface stands out as an established Puget Sound-based engineering solution resource… and this was simply another chance for us to just prove it again.”