Chuck Ruth, PE, SE, of SC Solutions was quoted in a news article by the Seattle Times reflecting on the challenges involved with the addition of light rail transit (LRT) on the I-90 Homer M. Hadley floating bridge.  The article highlights the innovative engineering solution required to successfully build and operate the world’s first LRT system on a floating bridge.  The solution involves an innovative “track bridge” system consisting of curved steel platforms and multiple sets of bearings to allow for rail movement caused by fluctuating lake levels and LRT traffic on the floating bridge.

The Seattle Times emphasizes the care and rigor that Sound Transit took in preparing to implement the first-of-a-kind solution.  Ruth is quoted as saying, “I think they tested everything they possibly could to have the biggest assurance of success with the track bridge system.”

As part of the track bridge design team, SC Solutions’ involvement in the project included development and analysis of 3D detailed finite element models to assess behavior and performance of track bridge concepts under dynamic loads.  Analysis cases included consideration of the full bridge/pontoon/train coupled system to evaluate train accelerations, rail stresses, and other response quantities.  SC Solutions’ analysis significantly contributed to the verification of the track bridge design to meet Sound Transit’s operational (train speeds, passenger comfort, etc.) and safety requirements.

The article can be viewed in its entirety on The Seattle Times website:

http://www.seattletimes.com/seattle-news/transportation/light-rail-track-floating-bridge-i-90-sound-transit/