The U830 project consists of approximately 3.15 miles of underground double track and systems light rail transit (LRT) line between Pine Street station and the University of Washington station. The LRT line is routed in an underground configuration with two bored tunnels and two cut-and-cover stations. The project included the installation of track, signaling, traction power substations, and overhead catenary system, communications, and SCADA systems for the University Link Extension. The project also included the replacement of communication and SCADA system elements across C-Link and the Downtown Seattle Transit Tunnel with minimal to no disruption to passenger service operations. All track and systems work took place in twin bored tunnels with only a portal for access. Access was via two large underground station complexes and the Downtown Seattle Transit Tunnel which could only be accessed during non-revenue service.
Sound Transit (ST) awarded MMJV [a Modern Railway Systems (MRS) and Mass. Electric Construction Company (MEC) Joint Venture], the Signal System Design and Installation of the U830 Project.
The MMJV signal subcontract included signal system design, furnish, installation, integration, testing and commissioning. The installation scope of work included two built-in signal relay rooms, over 200,000 ft. of signal cable, 70 impedance bonds, and 20 train signals in the newly finished transit tunnels. The signal design was completed in early 2014 and signal construction began in the third quarter of 2014. Testing, integration, and signal cutovers began in the first quarter of 2015 and concluded with revenue trains March 16, 2016.