
COMMISSION AGENDA – Action Item No. 8e Page 2 of 7
Meeting Date: April 11, 2023
Template revised June 27, 2019 (Diversity in Contracting).
JUSTIFICATION
Dock Structural Integrity
Originally designed and constructed in 1983 for recreational boats, Dock-E at Harbor Island
Marina has been providing moorage for large commercial tugs for over a decade and is currently
primarily utilized by long-time commercial tenants Global Diving and Western Towboat, as well
as other commercial marine vessel tenants on a more limited basis. As a result of the structural
load from heavier vessels, up to 94-ton (gross) and 120-feet in length, much of the dock’s piles,
walers, cleats, bollards, and pile hoops have been severely worn or damaged and these elements
have been repaired or upgraded over the last ten years by Marine Maintenance in a continual
effort to extend the dock’s capability to accommodate the tenant vessels’ berthing needs.
Additionally, although many of the original timber guide piles have been replaced with steel piles
as part of a facility programmatic replacement, some lower load capacity timber piles still remain.
All of these factors have contributed to Dock-E currently functioning with a reduced level of
structural integrity as well as requiring a higher rate of repairs and maintenance within its
remaining service life.
Economic Impact
This improvement project contributes directly to the jobs engine of the local maritime industry
cluster. Tugboats and towboats are an essential component of the maritime sector. As just one
measure of this value, the 2015 Ties that Bind report by The McDowell Group found that Seattle
and Tacoma continue to serve as the “lifeline” to Alaska as they capture 97% of cargo, by weight,
moved between Puget Sound and Alaska. This report examined the array of goods and services
that Alaska sources from Puget Sound. It found that in 2013 the total value of those goods and
services was $5.4 billion. Additionally, the more recent 2019 Community Attributes “Tri-Port”
Economic Impact study identified tug and barge operators that utilize Port of Seattle facilities
dockage and moorage leases generated nearly $2.4 million in revenue for the Port of Seattle in
2017.
DETAILS
Design and Environmental Sustainability
The proposed Dock-E Float and North Pier Improvements project was designated a Tier 2 project
under the Port’s Sustainable Evaluation Framework Policy Directive. As presented to the Energy
and Sustainability committee in 2021, the project team explored material alternatives to
minimize adverse environmental impacts, while still meeting determined design goals and
objectives. Accordingly, the project’s proposed environmentally beneficial improvements
include the following:
• Existing treated timber piles to be eliminated, reducing water quality impacts
• New steel piles and dock floats framework to be epoxy coated (rather than galvanized) to
reduce leaching of zinc into waterways