PND Engineers, Inc. is a full-service consulting engineering firm that
provides civil, marine, geotechnical, structural, surveying and
construction inspection services for a wide range of projects. The firm
was founded in 1979, with offices now located in Anchorage and
Juneau, Alaska, and in Seattle, Washington.
PND has performed planning, design, and construction inspection for
a significant number of marine facilities. These projects have included
the design of floating and fixed docks, passenger boarding gangways,
fender systems, and upland facilities that are used by various sized
vessels including cruise ships, ferry vessels, and recreational facilities
for pleasure craft. PND has the advantage of knowing the detailed
requirements related to all phases of the design, construction,
operation and maintenance for these types of projects.
P
N
D
E N G I N E E R S , I NC.
Headquarters:
Anchorage Office
Juneau Office
Seattle Office
1506 West 36th Avenue
9360 Glacier Highway, Suite 100
811 First Avenue, Suite 570
Anchorage, Alaska 99503
Juneau, Alaska 99801
Seattle, Washington 98104
Phone: 907.561.1011
Phone: 907.586.2093
Phone: 206.624.1387
Fax: 907.563.4220
Fax: 907.586.2099
Fax: 206.624.1388
P O O R S O I L S, H A R S H M A R I
E N V I R O N M E N T, D Y N A M I C
WAV E L O A D S , P O O R S O I L S
S E D IBREAKWATERS
M E N TAT I O N, S C O U R ,
PENETRATING
C O R RINCLUDING
O S I OPARTIAL
N , VA
RIABLE
AARRRTI H
EQ
R SUA K E
T I D EWAV
S , I CEE ,BE
S H O R E L I N E E RO S I O N, P O
O I L S, H A R S H M A R I N E
E N V I R O N M E N T, D Y N A M I C
WAV E L O A D S , P O O R S O I L S
S E D I M E N TAT I O N, S C O U R ,
C O R R O S I O N , VA R I A B L E
T I D E S , I C E , E A R T H Q UA K E
S H O R E L I N E E RO S I O N, P O
O I L S, H A R S H M A R I N E
P N D
E N V I R O N M E N T,E D Y NI A M I C
WAV E L O A D S , P O O R S O I L S
S E D I M E N TAT I O N, S C O U R ,
N G I N E E R S , N C.
c Copyright 2006, PND Engineers, Inc.
B R E A K WA T E R S
A breakwater is a structure protecting a harbor,
PND has specialists in
oceanography, coastal engineering
and marine construction. Specialists
have direct project experience that
includes all five shorelines of North
America (Arctic, Pacific, Gulf of
Mexico, Atlantic and Great Lakes) in
addition to projects overseas.
anchorage or shoreline from waves. There are
essentially three types: rubble-mound, vertical
wall, and floating.
PND’s coastal engineers are experienced in
designing all types of breakwaters and jetties,
through all the phases of projects, from concept
design through construction.
DESIGN CHALLENGES
PND has designed breakwaters in a
large range of site conditions:
Breakwater design is a challenging field in which designers
must rely upon sound judgment and experience to
efficiently solve problems associated with uncertainties in
various environmental conditions. Relative to other
engineering professions, design standards and codes often
do not address the wide array of potential design
conditions. Design demands the expertise and experience
of those who specialize in coastal engineering.
• Dynamic Wave Loads
• Poor Soils
• Scour
• Corrosion
• Sensitive Ecosystems with Stringent
Permitting Requirements
• Extremely Variable Tides
PND is well-qualified to analyze wind, wave, tide and
currents to determine wall heights, depths, and allowable
wave transmission for any number of site conditions,
including hindcast studies and wave reflection/refraction
analysis. PND also has experience in specialized areas that
can significantly affect project performance including boat
wakes, scour, propwash and corrosion protection.
• Ice
• Earthquakes
• Shoreline Erosion/Accretion
Structure Types for Typical Range of
Wave Height & Period
BREAKWATER TYPES
PN D | B RE AK WATER S
Wave Height (feet)
The choice of a breakwater type is largely dependent on
wave height and period. The largest waves require rubblemound structures that are able to absorb wave energy.
Floating breakwaters can be used for smaller wave heights
and periods, and allow for transient moorage space.
Vertical structural wall types address the range falling
between that of rubble-mound and floating breakwaters,
as shown in the diagram on the right.
30
25
20
Rubble-Mound and Filled Structures
15
Full-Height Vertical
Structural Wall
10
Partial Penetrating
Vertical Wall
5
Floating
5
10
15
20
25
Wave Period (seconds)
30
B R E A K WA T E R S
A breakwater is a structure protecting a harbor,
PND has specialists in
oceanography, coastal engineering
and marine construction. Specialists
have direct project experience that
includes all five shorelines of North
America (Arctic, Pacific, Gulf of
Mexico, Atlantic and Great Lakes) in
addition to projects overseas.
anchorage or shoreline from waves. There are
essentially three types: rubble-mound, vertical
wall, and floating.
PND’s coastal engineers are experienced in
designing all types of breakwaters and jetties,
through all the phases of projects, from concept
design through construction.
DESIGN CHALLENGES
PND has designed breakwaters in a
large range of site conditions:
Breakwater design is a challenging field in which designers
must rely upon sound judgment and experience to
efficiently solve problems associated with uncertainties in
various environmental conditions. Relative to other
engineering professions, design standards and codes often
do not address the wide array of potential design
conditions. Design demands the expertise and experience
of those who specialize in coastal engineering.
• Dynamic Wave Loads
• Poor Soils
• Scour
• Corrosion
• Sensitive Ecosystems with Stringent
Permitting Requirements
• Extremely Variable Tides
PND is well-qualified to analyze wind, wave, tide and
currents to determine wall heights, depths, and allowable
wave transmission for any number of site conditions,
including hindcast studies and wave reflection/refraction
analysis. PND also has experience in specialized areas that
can significantly affect project performance including boat
wakes, scour, propwash and corrosion protection.
• Ice
• Earthquakes
• Shoreline Erosion/Accretion
Structure Types for Typical Range of
Wave Height & Period
BREAKWATER TYPES
PN D | B RE AK WATER S
Wave Height (feet)
The choice of a breakwater type is largely dependent on
wave height and period. The largest waves require rubblemound structures that are able to absorb wave energy.
Floating breakwaters can be used for smaller wave heights
and periods, and allow for transient moorage space.
Vertical structural wall types address the range falling
between that of rubble-mound and floating breakwaters,
as shown in the diagram on the right.
30
25
20
Rubble-Mound and Filled Structures
15
Full-Height Vertical
Structural Wall
10
Partial Penetrating
Vertical Wall
5
Floating
5
10
15
20
25
Wave Period (seconds)
30
TR A DI T I O NAL BREAKWATER STRU C TU RES
ST. GEORGE RUBBLE-MOUND BREAKWATER
PORT ORCHARD WEST BREAKWATER
In the Pribilof Islands in Alaska, this rubble-mound, berm-type breakwater was
originally designed by PND in the early 1980’s. It provides moorage and safe
refuge for a fishing fleet. Physical conditions at St. George are extremely harsh,
with heavy icing and waves that reach up to 42 feet high.
After 22 years of extreme storms, a massive storm hit that caused non-critical
breakwater damage. Due to the exceptional past performance, PND was asked to
provide design repairs. Eight thousand cubic yards of quarry rock ranging from
50-2,500 pounds were required on the north shoreline, topped with 8,000 tons of
armor rock. The south breakwater arm required 18,000 tons of armor rock.
PND provided design for a floating breakwater at the Port
Orchard Marina on Washington’s Puget Sound that protects the
marina and serves as transient moorage. The marina has waves of
up to four feet in height.
LA CONNER G-FLOAT
Port Orchard West Breakwater is located
on the west side of the marina (to the
right of the above photograph).
CASCADE POINT MARINE FACILITY BREAKWATER
Cascade Point is the site of a rubble-mound breakwater that will protect floats
and a dock for a gold mine near Juneau, Alaska. The site is constrained by
relatively steep underwater slopes and the breakwater is designed to accommodate
future expansion. The typical armor rock size is nominally four feet in diameter. A
cross-section of the breakwater is shown below.
The La Conner breakwater is located on
the west side of the marina (in the front
of the photograph).
P ND | B RE A KWATER S
G-Float is a floating breakwater that provides protection for the
La Conner Marina North Basin in Washington. The breakwater is
an 800-foot x 9-foot modular concrete float on the marina’s outer
perimeter and also provides transient moorage.
TR A DI T I O NAL BREAKWATER STRU C TU RES
ST. GEORGE RUBBLE-MOUND BREAKWATER
PORT ORCHARD WEST BREAKWATER
In the Pribilof Islands in Alaska, this rubble-mound, berm-type breakwater was
originally designed by PND in the early 1980’s. It provides moorage and safe
refuge for a fishing fleet. Physical conditions at St. George are extremely harsh,
with heavy icing and waves that reach up to 42 feet high.
After 22 years of extreme storms, a massive storm hit that caused non-critical
breakwater damage. Due to the exceptional past performance, PND was asked to
provide design repairs. Eight thousand cubic yards of quarry rock ranging from
50-2,500 pounds were required on the north shoreline, topped with 8,000 tons of
armor rock. The south breakwater arm required 18,000 tons of armor rock.
PND provided design for a floating breakwater at the Port
Orchard Marina on Washington’s Puget Sound that protects the
marina and serves as transient moorage. The marina has waves of
up to four feet in height.
LA CONNER G-FLOAT
Port Orchard West Breakwater is located
on the west side of the marina (to the
right of the above photograph).
CASCADE POINT MARINE FACILITY BREAKWATER
Cascade Point is the site of a rubble-mound breakwater that will protect floats
and a dock for a gold mine near Juneau, Alaska. The site is constrained by
relatively steep underwater slopes and the breakwater is designed to accommodate
future expansion. The typical armor rock size is nominally four feet in diameter. A
cross-section of the breakwater is shown below.
The La Conner breakwater is located on
the west side of the marina (in the front
of the photograph).
P ND | B RE A KWATER S
G-Float is a floating breakwater that provides protection for the
La Conner Marina North Basin in Washington. The breakwater is
an 800-foot x 9-foot modular concrete float on the marina’s outer
perimeter and also provides transient moorage.
PARTIAL PENETRATING
WAVE BARRIER
The need to protect facilities from moderate-height waves has
led PND to develop the partial penetrating wave barrier, a vertical
barrier stopping short of the seafloor. In most situations, a
partial penetrating wave barrier is the best breakwater choice,
providing effective protection while minimizing the footprint
of the structure.
RESEARCH & DEVELOPMENT
PND has been leading research including physical/numerical
modeling on the partial penetrating wave barrier since it was
first designed at a Coast Guard facility in Oregon in 1980
(pictured at top left). Extensive model testing helped to
establish design methods and criteria published in 2001 that
addressed incident and transmitted wave heights, wave period
and length, run-up, and forces for various structural
configurations. From these criteria, suitable structural solutions
and use limitations can be developed for different soil
conditions, water depths, and other factors. Model testing has
been performed in wave tanks at B.C. Research, Inc., the U.S.
Naval Academy, Oregon State University, and PND.
CLEAR
ZONE
SYSTEM ADVANTAGES
SECTION & FOOTPRINT
Rubble-Mound Breakwater and
Partially Penetrating Wave Barrier
The size of the wave barrier increases as the
water depth increases.
PN D | B RE AK WATER S
- Reduces construction and maintenance costs
- Reduces construction time
- Minimal space required
- Allows natural basin flushing
- Minimizes impact on the marine environment
- Minimizes loading on submarine soils
- Reduces the breakwater's susceptibility to seismic damage
- Does not require rock quarrying and related activities
- May be attached directly to existing docks
- May be used as a part of foundation system for future docks
- Can be removed readily for modification or expansion
- Allows construction in deep water
BLA INE HA RBOR
HARBOR PROTECTION & PROMENADE
New partial penetrating wave barriers were installed at
the primary harbor entrance for the Port of Bellingham
at Blaine Harbor in Washington. The wave barriers
replaced deteriorating timber pile barriers protecting
the harbor's entrance. The timber pier was rehabilitated
and turned into a park. The new 580-foot wave barriers
vary from 20 to 50 feet in height from mudline, and
were designed to improve wave protection, decrease
maintenance costs, and provide additional space for
moorage just inside the entrance to the harbor.
The wave barriers used two different design styles
chosen to best fit varying site conditions. In shallower
water, a cantilever-type wave barrier was employed,
which consists of large-diameter pipe piles with partial
depth sheetpile barrier wings. The deeper water areas
necessitated use of Spin Fin™ batter clusters to handle
the repetitive tension / compression loads from wave
attack. The design surface waves have a significant
height of 6.2 feet, with period of 4.6 seconds.
The photo on the right depicts the wave barrier in
February of 2006, during the largest storm in
conjunction with the highest storm surge in 40 years.
PARTIAL PENETRATING
WAVE BARRIER
The need to protect facilities from moderate-height waves has
led PND to develop the partial penetrating wave barrier, a vertical
barrier stopping short of the seafloor. In most situations, a
partial penetrating wave barrier is the best breakwater choice,
providing effective protection while minimizing the footprint
of the structure.
RESEARCH & DEVELOPMENT
PND has been leading research including physical/numerical
modeling on the partial penetrating wave barrier since it was
first designed at a Coast Guard facility in Oregon in 1980
(pictured at top left). Extensive model testing helped to
establish design methods and criteria published in 2001 that
addressed incident and transmitted wave heights, wave period
and length, run-up, and forces for various structural
configurations. From these criteria, suitable structural solutions
and use limitations can be developed for different soil
conditions, water depths, and other factors. Model testing has
been performed in wave tanks at B.C. Research, Inc., the U.S.
Naval Academy, Oregon State University, and PND.
CLEAR
ZONE
SYSTEM ADVANTAGES
SECTION & FOOTPRINT
Rubble-Mound Breakwater and
Partially Penetrating Wave Barrier
The size of the wave barrier increases as the
water depth increases.
PN D | B RE AK WATER S
- Reduces construction and maintenance costs
- Reduces construction time
- Minimal space required
- Allows natural basin flushing
- Minimizes impact on the marine environment
- Minimizes loading on submarine soils
- Reduces the breakwater's susceptibility to seismic damage
- Does not require rock quarrying and related activities
- May be attached directly to existing docks
- May be used as a part of foundation system for future docks
- Can be removed readily for modification or expansion
- Allows construction in deep water
BLA INE HA RBOR
HARBOR PROTECTION & PROMENADE
New partial penetrating wave barriers were installed at
the primary harbor entrance for the Port of Bellingham
at Blaine Harbor in Washington. The wave barriers
replaced deteriorating timber pile barriers protecting
the harbor's entrance. The timber pier was rehabilitated
and turned into a park. The new 580-foot wave barriers
vary from 20 to 50 feet in height from mudline, and
were designed to improve wave protection, decrease
maintenance costs, and provide additional space for
moorage just inside the entrance to the harbor.
The wave barriers used two different design styles
chosen to best fit varying site conditions. In shallower
water, a cantilever-type wave barrier was employed,
which consists of large-diameter pipe piles with partial
depth sheetpile barrier wings. The deeper water areas
necessitated use of Spin Fin™ batter clusters to handle
the repetitive tension / compression loads from wave
attack. The design surface waves have a significant
height of 6.2 feet, with period of 4.6 seconds.
The photo on the right depicts the wave barrier in
February of 2006, during the largest storm in
conjunction with the highest storm surge in 40 years.
SHILSHOLE P IER A
WORK DOCK COMBINATION
A realigned partial penetrating wave barrier
structure with a concrete work dock was
constructed at Shilshole Marina's Pier A for
the Port of Seattle in Washington. The new
dock allows vehicle access for loading of
large vessels.
Partial depth steel sheet pile barrier wings,
welded onto the pipe pile, were driven and
attached to a steel beam to handle wave
loads. Spin Fin™ batter clusters were used
to convert the wave forces into tension and
compression to transfer forces into the soil.
The batter pile clusters were also used to
support the precast concrete promenade.
Floats on the back side of the dock were
included for 100-foot vessels.
The top photo shows the West Basin
prior to breakwater construction. The
large photograph depicts the 22 additional
moorage locations.
WE S T BAS I N WAV E BARRIER
HARBOR PROTECTION & EXPANSION
A partial penetrating wave barrier in Astoria, Oregon provided expansion room
for 22 additional 60-foot vessel slips by eliminating a filled bulkhead system. The
alignment of the new breakwater allowed for the additional moorage.
The West Basin marina is located near the mouth of the Columbia River in
Oregon where there are strong currents, high winds and ocean-going cargo
vessels. The largest design loads are developed by 4.9-foot high significant waves
with 4.3-second periods. A cantilever-style wall was selected that consists of
large-diameter pipe piles with sheetpile barrier wings. This design provided the
best wall alignment to protect the harbor without impeding access and creating
wave-reflection issues. A typical section is shown to the right.
PN D | B RE AK WATER S
CLEAR
ZONE
The placement of the wave barrier on the
inside face of the pier and the openings for
fish passage have improved the flushing of
water through the marina.
SHILSHOLE P IER A
WORK DOCK COMBINATION
A realigned partial penetrating wave barrier
structure with a concrete work dock was
constructed at Shilshole Marina's Pier A for
the Port of Seattle in Washington. The new
dock allows vehicle access for loading of
large vessels.
Partial depth steel sheet pile barrier wings,
welded onto the pipe pile, were driven and
attached to a steel beam to handle wave
loads. Spin Fin™ batter clusters were used
to convert the wave forces into tension and
compression to transfer forces into the soil.
The batter pile clusters were also used to
support the precast concrete promenade.
Floats on the back side of the dock were
included for 100-foot vessels.
The top photo shows the West Basin
prior to breakwater construction. The
large photograph depicts the 22 additional
moorage locations.
WE S T BAS I N WAV E BARRIER
HARBOR PROTECTION & EXPANSION
A partial penetrating wave barrier in Astoria, Oregon provided expansion room
for 22 additional 60-foot vessel slips by eliminating a filled bulkhead system. The
alignment of the new breakwater allowed for the additional moorage.
The West Basin marina is located near the mouth of the Columbia River in
Oregon where there are strong currents, high winds and ocean-going cargo
vessels. The largest design loads are developed by 4.9-foot high significant waves
with 4.3-second periods. A cantilever-style wall was selected that consists of
large-diameter pipe piles with sheetpile barrier wings. This design provided the
best wall alignment to protect the harbor without impeding access and creating
wave-reflection issues. A typical section is shown to the right.
PN D | B RE AK WATER S
CLEAR
ZONE
The placement of the wave barrier on the
inside face of the pier and the openings for
fish passage have improved the flushing of
water through the marina.
C APE D ISAPPOIN TM EN T
BOAT LAUNCH PROTECTION
PND provided services to the Washington State Parks
Department for a partial penetrating wave barrier at
Cape Disappointment State Park in Southern
Washington State. The barrier protects a three-lane
recreational boat launch facility, and was designed to
replace an old timber barrier. The new cantilever wave
barrier is approximately 250 feet in length and
consists of galvanized pipe piles with sheet pile wings.
The partial penetrating design was selected because
of its low environmental impact and small footprint.
The barrier design also has a separation that allows
for fish passage.
BELL STREET PIER
CRUISE SHIP FACILITY
Bell Street Pier is a waterfront facility in
downtown Seattle, Washington that provides
public moorage, cruise ship operations, a
maritime museum, a conference facility, and
waterfront restaurants. The harbor is protected
with a 900-foot partial penetrating wave barrier
with lateral resistant battered Spin Fin™ piles.
The wave barrier was designed to resist storms
producing 8-foot significant height waves with
six-second periods. The wave barrier face
extends into the water 32 feet at low tide. It is
comprised of 48-inch diameter pipe piles placed
12 feet on-center acting as the vertical bending
members. Bridging the gap between these piles
are eight-inch-thick prestressed concrete panels.
The height of the structure from mudline varies
between 55 and 75 feet.
A three-dimensional wave model of the
surrounding Elliot Bay (bottom right) was used
to verify wave climate and barrier efficiency at
B.C. Research Lab in Vancouver, Canada.
PN D | B RE AK WATER S
C APE D ISAPPOIN TM EN T
BOAT LAUNCH PROTECTION
PND provided services to the Washington State Parks
Department for a partial penetrating wave barrier at
Cape Disappointment State Park in Southern
Washington State. The barrier protects a three-lane
recreational boat launch facility, and was designed to
replace an old timber barrier. The new cantilever wave
barrier is approximately 250 feet in length and
consists of galvanized pipe piles with sheet pile wings.
The partial penetrating design was selected because
of its low environmental impact and small footprint.
The barrier design also has a separation that allows
for fish passage.
BELL STREET PIER
CRUISE SHIP FACILITY
Bell Street Pier is a waterfront facility in
downtown Seattle, Washington that provides
public moorage, cruise ship operations, a
maritime museum, a conference facility, and
waterfront restaurants. The harbor is protected
with a 900-foot partial penetrating wave barrier
with lateral resistant battered Spin Fin™ piles.
The wave barrier was designed to resist storms
producing 8-foot significant height waves with
six-second periods. The wave barrier face
extends into the water 32 feet at low tide. It is
comprised of 48-inch diameter pipe piles placed
12 feet on-center acting as the vertical bending
members. Bridging the gap between these piles
are eight-inch-thick prestressed concrete panels.
The height of the structure from mudline varies
between 55 and 75 feet.
A three-dimensional wave model of the
surrounding Elliot Bay (bottom right) was used
to verify wave climate and barrier efficiency at
B.C. Research Lab in Vancouver, Canada.
PN D | B RE AK WATER S
PND Engineers, Inc. is a full-service consulting engineering firm that
provides civil, marine, geotechnical, structural, surveying and
construction inspection services for a wide range of projects. The firm
was founded in 1979, with offices now located in Anchorage and
Juneau, Alaska, and in Seattle, Washington.
PND has performed planning, design, and construction inspection for
a significant number of marine facilities. These projects have included
the design of floating and fixed docks, passenger boarding gangways,
fender systems, and upland facilities that are used by various sized
vessels including cruise ships, ferry vessels, and recreational facilities
for pleasure craft. PND has the advantage of knowing the detailed
requirements related to all phases of the design, construction,
operation and maintenance for these types of projects.
P
N
D
E N G I N E E R S , I N C.
Headquarters:
Anchorage Office
Juneau Office
1506 West 36th Avenue
9360 Glacier Highway, Suite 100
Anchorage, Alaska 99503
Juneau, Alaska 99801
Phone: 907.561.1011
Phone: 907.586.2093
Fax: 907.563.4220
Fax: 907.586.2099
Seattle Office
Houston Office
1736 Fourth Avenue S, Suite A
10497 Town and Country Way, Suite 210
Seattle, Washington 98134
Houston, Texas 77024
Phone: 206.624.1387
Phone 832.930.4830
Fax: 206.624.1388
PND Engineers Canada, Inc.
Vancouver Office
Suite 2000, Oceanic Plaza
1066 West Hastings Street
Vancouver, BC V6E 3X2
Phone: 604.601.5247
For additional information please visit our website.
www.pndengineers.com
P O O R S O I L S, H A R S H M A R I
E N V I R O N M E N T, D Y N A M I C
WAV E L O A D S , P O O R S O I L S
S E D IBREAKWATERS
M E N TAT I O N, S C O U R ,
PENETRATING
C O R RINCLUDING
O S I OPARTIAL
N , VA
RIABLE
AARRRTI H
EQ
R SUA K E
T I D EWAV
S , I CEE ,BE
S H O R E L I N E E RO S I O N, P O
O I L S, H A R S H M A R I N E
E N V I R O N M E N T, D Y N A M I C
WAV E L O A D S , P O O R S O I L S
S E D I M E N TAT I O N, S C O U R ,
C O R R O S I O N , VA R I A B L E
T I D E S , I C E , E A R T H Q UA K E
S H O R E L I N E E RO S I O N, P O
O I L S, H A R S H M A R I N E
P N D
E N V I R O N M E N T,E D Y NI A M I C
WAV E L O A D S , P O O R S O I L S
S E D I M E N TAT I O N, S C O U R ,
N G I N E E R S , N C.
c Copyright 2015, PND Engineers, Inc.