A Coast Guard vertical clearance determination dealt a blow to elevated light rail options for Ballard Link, giving tunnel alternatives a boost — not to mention superrich superyacht owners.
In order to accommodate the superyacht community, the United States Coast Guard has determined that fixed bridges crossing Seattle’s Ship Canal between Puget Sound, the Ballard Locks, and Fremont must have at least 205 feet of vertical clearance. Such bridges would be 70 feet higher than the Aurora Bridge and 150 feet higher than the Ballard Bridge when closed.
This determination was made specifically for Sound Transit’s planned extension of light rail to Ballard, but similar findings impacted plans for replacing the Salmon Bay rail bridge and will steer the future replacement of the Ballard Bridge. Horizontal bridge clearances were also included in the determination, with some proposed Sound Transit bridge designs found to require wider clearances to avoid collisions in the narrow channel. Thus, Coast Guard guidance also limits the moveable bridge alternatives that Sound Transit and likely drives up their cost by requiring wider spans in the moveable section.
The 205-foot vertical clearance requirement was guided by comments from maritime stakeholders in the area. Several groups — including businesses, the National Marine Trade Association, and the Port of Seattle — are attempting to create a cluster of superyacht service facilities in Seattle. Such private ships are sized to clear height limits in global ports. Seattle’s competitiveness in this market depends on accommodating such vessels.
Coast Guard Sound Transit Letter by Natalie Bicknell on Scribd
