BREMERTON FLOATING WAVE ATTENUATOR

AMERICAN SOCIETY OF CIVIL ENGINEERS
2007 REGION 8 PROJECT OF THE YEAR AWARDS
PORT OF BREMERTON
BREMERTON FLOATING WAVE ATTENUATOR
AUGUST 29, 2008

Describe the Project’s pre-eminent qualifications for the Award in this category:
o Scaled model tests and several iterations were used to develop optimum concept design
o 12 individual floating bodies with a maximum weight of 950 tons were safely fabricated, launched,
transported to the site via tug boats, and rigidly connected by post-tensioning in the water without
leakage.
o The 12 individual floating bodies behave as single floating structure moored with 50 different
mooring lines.
o Reid Middleton’s fine-tuned QC program allowed the wave attenuator to meet the appropriate
freeboard, stability, and connection safety requirements.
o Bremerton Floating Breakwater is the first large-size floating concrete breakwater in the state of
Washington to use cast-in-place type, ready-mixed concrete from four different types of concrete
mix in the fabrication.
o The floating breakwater was also fabricated using a mix of lightweight sand imported from Colorado
with normal fine aggregate.
o The new wave attenuator serves as both a breakwater for the Bremerton Marina and a public
waterfront park.
o Unlike fixed-type breakwaters, the floating breakwater is fish friendly, as it allows fish and other
marine species to pass freely underneath the structure. The new breakwater required a shorter inwater
work-period than the fixed type because it was fabricated and transported on land, then
launched in the water, and moved by tugboats to its final destination where the final installation
occurred.
o The floating structure is designed to last more than 50 years. It allows for minimum maintenance
and maximum durability. Part of the inboard side of the breakwater will provide permanent moorage
services for large boats, providing the Port with additional revenue.
o Bremerton Floating Wave Attenuator/waterfront park will be equipped with unique light poles,
benches, and sculptures.
o Fly ash, an industrial byproduct, was used in the construction, which decreased the amount of
cement in the concrete mixes by approximately 15%.
o Plastic timber and Fiber Reinforced Plastics were used for ladder and rub-rails instead of natural
timber and steel, which usually deteriorate and rust over time.
DEADLINE: Close of Business AUGUST 29, 2008
Submit three (3) copies of the completed nomination package to:
Electronic submittals can also be made however please confirm to ensure they are received, if over
10MB in size an FTP site will be made available for your submittal.
A nomination package should include the following:
Michael J. Barton, PE, PTOE, F.ASCE
ASCE Chair Awards Committee, Region 8
5210 E. Williams Circle, Suite 530
Tucson, Arizona 85711
michael.barton@hdrinc.com
• A cover letter, signed by the nominator;
• The Project’s background information;
• A color photograph of the Project; and
• Letters of recommendation supporting the nomination, but not required.
The entire nomination package should not exceed 10 pages.
Page 2 of 2

Excellence in Design
Prior to design development and final design for construction, optimum concept design was selected
throughout iterations with several experiments (scaled model tests) and analyses. Approximately 12 individual
floating bodies with a maximum weight of 950 tons were safely launched and transported. These were then
rigidly connected by post-tensioning in the water without any leakage. The 12 connected attenuator bodies
behave as a single floating structure moored with 50 different mooring lines.
Additional weights and wind areas for future artistic sculptures were evaluated and several counterweights
and concrete benches were designed and installed, which allowed the Port of Bremerton to install actual
benches and various artistic features once the breakwater was installed.
Reid Middleton’s fine-tuned QC program allowed the wave attenuator to meet the appropriate freeboard,
stability, and connection safety requirements by using a series of iterations with weight/buoyancy calculations,
monitoring, and ballasting.
Innovative Features
The Bremerton Floating Breakwater is the first
large-size floating concrete breakwater in the
state of Washington to use cast-in-place type,
ready-mixed concrete from four different types of
concrete mix in the fabrication of the breakwaters.
This was achieved by blending lightweight
fine aggregate imported from Colorado with
normal fine aggregate to meet the required
target strength, free board, and stability.
Contribution to Public Welfare & Safety
The new wave attenuator will serve as both a breakwater for the Bremerton Marina and a public waterfront
park. The public will enjoy a long waterfront park very close to Puget Sound water. Bremerton residents and
visitors will have the opportunity to fish from the breakwater, walk, or sit and enjoy the views. There will also
be many events and activities that will take place on the top surface of the floating attenuator. For example,
Bremerton’s annual blackberry festival on Labor Day will take place here.
Compatibility with the Environment
Port of Bremerton
Floating Wave Attenuator
Project Description
2007 ASCE Region 8 Project of the Year Awards
Unlike fixed-type breakwaters (wave walls or mound
type), the floating breakwater is especially fish
friendly, as it allows fish and other marine species to
pass relatively freely underneath the structure. The
new breakwater also required a shorter in-water
work-period than the fixed type because it was
fabricated and transported on land, then launched
in the water, and moved by tugboats to its final
destination where the final installation occurred.

Cost-Effectiveness
Port of Bremerton
Floating Wave Attenuator
Project Background
The durable floating structure is designed to last more than 50 years providing long side-tie moorage spaces
for large boats. The breakwater design was cost-performance effective. It allows for minimum maintenance
and maximum durability. Part of the inboard side of the breakwater will provide permanent moorage services
for large boats, providing the Port with additional revenue. Additionally, a surface area lease plan of the
breakwater may be created by the Port of Bremerton for events that take place at the breakwater site.
Aesthetics
Unlike many massive fixed-type breakwaters, the
Bremerton Floating Wave Attenuator/waterfront park will
be equipped with unique light poles (same ones used in
downtown Bremerton), secured side-tie moorage areas
for large boats, benches, and sculptures. It is a beautiful
modern floating waterfront park.
Effective Use of Materials
Durable high-performance, lightweight materials were
used in the successful construction of the Port’s new
floating wave attenuator. High strength, corrosion-resistant
reinforcement was used at critical locations enhancing the structural capacity and durability. Lighweight
fine aggregate imported from Colorado as well as fly ash, an industrial byproduct, were used in the construction,
which decreased the amount of cement in the concrete mixes. More than 10 different grout materials
and 10 different polymeric adhesives were used for post-tensioning, body connections, waterproofing, hardware
installation, and patching. Plastic timber and FRP (Fiber Reinforced Plastics) were used for ladder and
rub-rails instead of using natural timber and steel, which usually deteriorate and rust over time.
2007 ASCE Region 8 Project of the Year Awards

3/64" = 1'-0"
3/64" = 1'-0"
3/64" = 1'-0"

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Port of Bremerton Floating Wave Attenuator - Breakwater & Mooring Lines Layout
ASCE Region 8 Project of the Year Awards
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Port of Bremerton Floating Wave Attenuator - Mooring Line Side Elevation
ASCE Region 8 Project of the Year Awards
Figure 2

Photo 1: Wave attenuator model tests at Oregon State University wave lab.

Photo 2 (above): 950-ton individual body being transported from casting to launching site.
Photo 3 (above): 135 foot-long individual body being launched.

Photo 4: 450 foot-long bent body being towed to Bremerton Marina site.

Photo 5: Aerial photo of the Bremerton Floating Wave Attenuator and expanded marina.