HomeMy WebLinkAboutEmmonak Small Boat Dock Design Report 2000
Small Boat Dock
esign Study Report
Prepared for:
The City of Emmonak
Prepared by:
Morgan Merritt, P.E.
LOMF Incorporated
A subsidiary of Ukpeagvik Inupiat Corporation f
139 East 51st Avenue Voice: (907) 273-1830 Anchorage, Alaska 99503 Fax. (907) 273-1831
February 16, 2000
Emmonak Small Boat Dock
Design Study Report _ City of Emmonak
Table of Contents
I.
Il.
iil. CONCEPTUAL DOCK DESIGN .............ccccccescceseeeeesseeeeeneeeeseeeeseeneeeseeeeeeeeaeeeeeteee 3
A. Location ............c ee a3
B. Anchoring System ..............cccccccecseeeeseeeseeeeeneeeseneeeceseeeeeneeecsseeecsnseeeseeseniaes 3
C. CatwallKS.........cccccccccccccccessceecceeeseeeeeceeseaeeeeeecsneeeceeceesieeeseseenteteeeteenieeeeeenss 3
D. Float Structure Types... 4
1. Concrete .............. 4
2. Metal............. 4
3. Polyethylene ............... 4
4. Pontoon Fill Material ...............0.0ccccccccccccecceeceeeeeeeeeeeseeeeeeeeeeeeeeneteeeeeeeeennee 5
E. Decking ............0eeeeeeeeeeee 5
1. Concrete... 5
2. Aluminum.. 6
3. WO0d 00 o eee cceceecccccccceseceessececsaeescsseeecsseeccseeecsseeeeseseeeccseeeeteeeceteeesteeeestrees 6
F. FOMGOIS roses oo. ove siececcescecseceedcnscvesenssevesesnsctoceeesdvecedecedectscveseccessssssvorebersdcsectee 6
G. Miscellaneous Features ...............c cece ccccceccceccesseeeceeceesseeeeeesenseeeeeeestteeeeeeess 7
IV. RECOMMENDATIONG .............::ccccccssssccceeesssccceeeeessceeeeessneceeeeeeseaeeeeeeseeeeeeeeeseeeeeeees 7
A. Design Requirement. ..............::ccecccecececeeecececeeeeeeeeeeeeeesereeeeeeneeeneeenseseeeees 7
B. POPIMUUTEIING oo cseoesseccecscssececescsessctecsuccepseancessteceeuaceagececsseceetesce-ceautersstseuecsenssatse 8
C. Cost Estimate ......0...0.ccccccccccecceceteeeeeeeeceeeeeeeeeeeeeeeeeeneeeeneeesseessneesnneeeess 9
D. SCHEMUIE 0... cece ccccecceeccessaeeeeeceseseeeeeecceeeeeeeeseseseeececeenseeeseeeeteeeeeeees 9
E. Annual Storage ............cccccccceesceeeeeseeesesseeceeeeseecseeccseeeseenseeeseeeneeenseesteenaes 9
FIGURES:
Figure 1 - Vicinity Map
Figure 2 - Site Plan
Figure 3 - Layout Plan
Figure 4 - Catwalk Landing
Figure 5 - Alternate Float Concepts
Figure 6 - Dock Details
Figure 7 - Detail
LCMF Incorporated ()
A subsidiary of Ukpeagvik Inupiat Corporation 1 ew”
Emmonak Small Boat Dock
Design Study Report City of Emmonak
I. INTRODUCTION
The City of Emmonak is an Alaskan village located on Kwiguk Pass (a channel at the mouth of
the Yukon River) only ten miles from Norton Sound. The City was incorporated in 1964 and in
1996 had population of 784. The major industry is fishing (See Figure 1).
Significant fuel system improvements are to be constructed in Emmonak in the summer of
2000. In the process of planning for those improvements, concerns have been raised
regarding the safety of fueling boats from shore. Up to 4 foot diameter armor stone has been
placed along this bank of the river to protect the site from erosion. This rock, which is set at
almost a 2:1 slope is very dangerous for people to be walking, particularly carrying loads such
as fuel containers or fuel hoses. It has been proposed to construct a floating dock adjacent to
the new fuel pump location, however, there are significant problems to anchoring a floating
dock in this river, which is subject to significant ice flow each spring (See Figure 2).
Il. | SITE CONDITIONS
A. General
Kwiguk Pass, in the lower Yukon, experiences 5 knot currents and is reported to have waves
up to three feet high. These waves probably do not have the long periods and high energy of
ocean waves of similar height, but can be destructive to objects in the river. The bank is
covered with large stone, up to 4 foot in diameter, placed at approximately 2:1 slope down into
the river. The river is over 20 feet deep at this point. A barge used for processing fish is
located directly upstream from the intended dock location. Site visits by the Corps of
Engineers and conversations with residents indicate that water level comes to within 2 feet of
the top of the bank at extreme high water and is approximately 7 feet below the top of the
bank at extreme low water.
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Emmonak Small Boat Dock
Design Study Report City of Emmonak
B. Design Vessel
The design vessels for this dock are to be the typical 22 foot aluminum skiff that runs the river.
These high speed boats, some with inboard motors, can be heavily loaded, but are relatively
small craft. Berthing and mooring loads from the skiffs would be far less than the wave and
current forces on the dock. There are some 65-foot-long surplus landing craft vessels used in
the area, but it is recommended that they use the dock only in calm weather conditions.
Ill. CONCEPTUAL DOCK DESIGN
A. Location
The dock is to be located as near as possible to the planned fuel pump on the bank. This is
approximately 75 feet down stream from a location where the fish processing barge is usually
anchored on a seasonal basis. See Figure 3.
B. Anchoring System
Anchor piles should not be set in the river due to damage from spring time ice action.
Therefore, it is proposed to construct a shore-side anchoring system, consisting of concrete
deadmen (see Figure 4) that serve as ramps onto catwalks and an additional deadman for an
upstream anchor cable. Anchor cables would also cross brace the catwalks to resist upstream
and downstream forces that could arise from current, berthing, and mooring loads. See Figure
3.
C. Catwalks
The catwalks in the anchoring system would act as struts to hold the dock in position from
shore. The catwalks could be either steel or aluminum and would have to be constructed with
a truss-like shape to withstand buckling from loads at the dock face. The catwalks would be
LCMF Incorporated aN
ter”
A subsidiary of Ukpeagvik Inupiat Corporation
Emmonak Small Boat Dock
Design Study Report City of Emmonak
attached with hinges at either end (one to the concrete deadmen/ramp and the other end to
the floating dock) to compensate for changes in river stage.
D. Float Structure Types
Several materials are available for floats, including concrete, metal, wood, and polyethylene.
1. Concrete
Reinforced concrete floats are corrosion resistant, strong, and offer a durable option for floats.
Typical concrete floats consist of high strength concrete reinforced with galvanized wire mesh
encasing a foam core (See Figure 5). Although precautions are taken to prevent cracking due
to temperature extremes and stress, there is a concern for the use of concrete at this location,
due to the possibility of ice loading during the winter and difficulty of obtaining high quality
concrete at this location for repairs.
2. Metal
Float structures can be made of corrosion resistant aluminum alloys or galvanized steel.
Aluminum pontoons or aluminum box structures filled with foam provide excellent flotation for
many recreation use docks around the country. Aluminum skinned flotation would weigh less
than a concrete dock, and therefore would be more easily maneuvered if they had to be taken
from the water for repair or seasonal storage. Aluminum should be more durable than
concrete or wood under repeated loads from berthing vessels and ice loads during storage.
3. Polyethylene
Polyethylene floats either pipes or tub type, make excellent floatation for floating docks.
Polyethylene is extremely abrasion resistant and durable. Typical polyethylene floats consist
of high density polyethylene (HDPE) casing with a black ultraviolet light inhibitor, filled with
foam, and connected to a treated wood superstructure. Aluminum, wood, or galvanized steel
superstructures would also be compatible with HDPE pontoons and, unlike wood, would be
LCMF Incorporated (/_\) A subsidiary of Ukpeagvik Inupiat Corporation 4 Net”
resistant to the water logging and long term degradation.
Emmonak Small Boat Dock
Design Study Report _ City of Emmonak
Figure 5 illustrates a pontoon design utilizing molded aluminum pipes. Similar configurations
using polyethylene pipes or tubs are also available. Typical thin walled polyethylene floats are
less expensive and less durable than other alternatives for this application. These floats would
be expected to suffer some damage during the annual removal and reinstallation. Thick-walled
HDPE pipes, though heavier, would be far more durable than the thin wall culvert material
typically used. Damaged polyethylene floats can be repaired by cold processes (epoxy repair
kits).
4. Pontoon Fill Material
One of two types of foam materials will be selected for the pontoon fill: expanded polystyrene
(EPS) or urethane. The EPS weighs about one pound per cubic foot, and, in the event of
leaks in the pontoons, has a maximum absorption of 3-percent, by volume. EPS is also
susceptible to chemical breakdown when exposed to water-borne hydrocarbons.
Urethane foam weighs about two pounds per cubic foot and is relatively impervious to water
and hydrocarbons, but is slightly more expensive than EPS. Encasing the foam in hard plastic
or metal is necessary to prevent damage.
E. Decking
Three types of decks were considered: concrete, aluminum, or wood.
1. Concrete
Concrete decking would be durable and slip-resistant. Concrete can be corrosion resistant but
very heavy and may cause removal problems if the entire dock is constructed of foam filled
concrete. On the other hand, additional weight would add to the stability of the dock. A
concrete deck poured on an aluminum shell is worth considering in this application.
LCMF Incorporated /_\)
eI”
A subsidiary of Ukpeagvik Imupiat Corporation
Emmonak Small Boat Dock
Design Study Report City of Emmonak
2. Aluminum
Aluminum decking is light weight, durable, and can be purchased with a ridged, non-slip finish.
Aluminum is more expensive but more durable than wood or concrete decking. Although it can
be cut or bent from impacts, it will not rot, splinter or become water logged like wood and will
not crack or spall like concrete. The community of Emmonak reports that it has weldors
qualified for aluminum welding in case decking or structural sections need repair or
replacement.
3. Wood
Conventional treated wood decking is fairly durable and corrosion resistant, although it does
deteriorate over time from exposure to ultraviolet radiation and water, and treated wood will
corrode aluminum on contact. Wood decking may be slippery without some traction matting
but does permit cargo and gear to be pulled along without damage. Wood decking can be
easily repaired or replaced and is relatively inexpensive. It is not recommended for this
application because heavy wear will result in frequent maintenance.
F. Fenders
Fenders for the floating dock will consist of either wooden rub strips or molded rubber.
Wooden strips (2 x 10s) are inexpensive and easily repaired, but may mar the boat hulls.
Wood fenders on other docks have shown considerable wear, and sometimes fasteners
securing the wood have become exposed, causing damage to vessels. Because of the
heavily laden fishing skiffs and the wave environment at this site wood fenders are not
recommended for this application.
Rubber fenders are very durable and reduce damage to moored craft, but are more expensive
than wood. Tires, cut in short sections and stretched along the edge of the dock would be an
inexpensive alternative to the commercial rubber fenders. Tires are less attractive than the
LCMF Incorporated /\)
A subsidiary of Ukpeagvik Inupiat Corporation
Emmonak Small Boat Dock
Design Study Report City of Emmonak
fenders but have worked successfully at other dock facilities. Prefabricated molded rubber
fenders are recommended for their superior protection of vessels and their durability. See
Figure 7.
G. Miscellaneous Features
Some additional features that may be of concern are bullrails to prevent people and objects
from falling off the dock, cleats for securing vessels to the dock, and slip-resistant surfaces for
ramps, catwalks, and dock to provide safe footings for the users of the facility (see Figures 6 &
7). Although they are not shown in the figures, a safety ladder and lifesaving ring should be
considered in the final design. To simplify transport and storage the floating dock and catwalk
designs should include fork tubes and crane pick points.
IV. RECOMMENDATIONS
It is the conclusion of this study that, at this site, a floating dock is feasible and recommended
for safety and efficiency of the fueling system.
A. Design Requirements
To provide a dock with the lowest operation and maintenance costs and the greatest durability
and usability, the following features are recommended:
e Design Loads:
Wind: 80 mph
Wave: 3 feet
Current: 5 knots
Dead Loads: All
Uniform Live Loads: Dock, 40 Ib. psf minimum
Catwalk, 20 psf minimum
Concentrated Live Load: 500 lb.
LCMF Incorporated ((_\ A subsidiary of Ukpeagvik Inupiat Corporation 7 —
Emmonak Small Boat Dock
Design Study Report City of Emmonak
e Freeboard:
Dead Load Only: 14 to 24 inches
Dead and Uniform Live Loads: 12 inches minimum
Dead and Concentrated Live Load: 12 inches minimum
e Recommended Features:
Shore Anchoring System - Concrete Deadman/Ramps
Metal Catwalks
Aluminum Floating Dock constructed of 6061-T6 or other corrosion resistant
alloy
Urethane Foam Fill
Aluminum Deck
6-inch Tall Bullrail
Metal Cleats
Molded Rubber Fenders
Slip-resistant surfaces
Ladder
Life Saving Ring
Fork Tubes and Crane Pick Points
B. Permitting
Costs and time requirements of permitting should be considered when planning for this facility.
An Army Corps of Engineers permit will be necessary because this dock will be a structure in
navigable waters of the United States. The Corps process includes the Coastal Zone
Questionnaire and comments from state and federal agencies. Alaska Department of Fish and
Game must be consulted and may require a permit application. Also, the river is State of
Alaska property and will require a permit from the DNR at least, and may even require a
Tidelands Survey and lease. Permitting will probably take from 60 to 120 days. Costs will
probably be in the range of $3,000 to $8,000 depending mainly on agency responses to the
applications.
LOMF Incorporated
Newt”
A subsidiary of Ukpeagvik Imupiat Corporation
Emmonak Small Boat Dock
Design Study Report City of Emmonak
Cc. Cost Estimate
Final Design and Inspection $15,000
Permitting 5,000
Prefabricated Floating Dock 15,000
Prefabricated Catwalks 10,000
Freight to Emmonak 20,000
Anchoring System and Assembly of Dock and Catwalk 20,000
Contingency 20,000
Total Construction Cost $105,000
D. Schedule
Assuming that funding is not available to complete design and begin permitting until this
summer, it would not be possible to construct and deploy the docks at a useful time before fall
freeze-up. If funding is available it is recommended to construct the shore side improvements
this fall, and to have the floating dock and catwalks delivered in the spring of 2001 to be
deployed after breakup of the spring of 2001.
E. Annual Storage
It will be necessary to take the dock and catwalks from the river each fall to avoid ice damage
the following spring. The fish processing barge is towed from its summer season mooring
location to a nearby slough each fall before freeze-up. The calm conditions in the slough
protect the barge from the spring ice currents. The floating dock could be treated in a similar
manner. The floating dock could be loaded with the catwalks then towed with the fish
processing barge to the protected waters of the slough before ice formation. The dock would
LCMF Incorporated aN
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A subsidiary of Ukpeagvik Inupiat Corporation
Emmonak Small Boat Dock
Design Study Report City of Emmonak
be allowed to freeze in the slough, and after breakup the dock would be brought back with the
fish processing barge and reanchored at its seasonal operating location.
An alternate storage method would be to remove the catwalks and float from the water and
store them some distance from the bank to protect them from ice action. The catwalks and
floats could be picked with a loader or small crane. If a smooth ramp is available, inexpensive
dollies could be constructed for deploying and removing the dock like a boat on a trailer.
W:\ENG-DOC\99049 Emmonak Dock\Report3. DOC
LCMF Incorporated /.\)
A subsidiary of Ukpeagvik Inupiat Corporation 10
PLOTTING DATE: 01/31/00 (16:10) AUTOCAD DRAWING NAME: 049—VM.DWG PROJECT SITE
BERING
SEA
Kaktovik
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NTS
5280
VICINITY MAP
1” = 1 MILE
LCMF Incorporated f A subsidiary of Ukpeagvik Ifiupiat Corporation
Anchorage, Alaska (302) 562-1830 ee Barrow, Alaska 907) 852-8212
FIGURE 1
CITY OF EMMONAK
DOCK CONCEPTUAL DESIGN
LOCATION AND VICINITY MAP
EMMONAK, ALASKA
DATE: 1/31/2000 | DRAWN BY: KK SHEET:
SCALE: AS SHOWN | CHECKED BY: MPM W.O. No: 99-049
AUTuLav URAWING NAME: 049-DUSP1.DWG PLOTTING DATE: 01/31/00 (16:16) |
|
EXISTING ROAD ED
PARCEL “E”
PROPOSED FUEL OFFICE
PROPOSED GASOLINE/
DIESEL MARINE HEADER
SITE PLAN
1” = 40°
LCMF
EMMONAK CORPORATION
EXISTING RIVER BANK EROSION CONTROL (RIP—RAP)
A subsidiary of Ukpeagvik Ifiupiat Corporation
Anchorage, Alaska 907) 562-1830 Barrow, Alaska
Incorporated is »)
907) 852-8212 “e
SCALE: = 40’
a EXISTING RRS Sy PARCEL "D” SS g@qq WAN
ROAD EDGE
ae SEASONAL USE FLOATING FUEL DOCK SEE FIGURE 3 60'x150° —_—______
FISH PROCESSING CL
BARGE
CITY OF EMMONAK
DOCK CONCEPTUAL DESIGN
SITE PLAN
EMMONAK, ALASKA
DATE: 1/31/2000 | DRAWN BY: KK 1” CHECKED BY: MPM
. -TTING vAIt: 01/31/00 (16:04) AUTGunu URAWING mwamE: O49—-uLr.DWG wen A TOI SKOO} TRO — eee Ly Yyfp IR 4 oe 0 10
SCALE IN FEET
EXISTING RIVER Sj BANK EROSION CONTROL (RIP—RAP)
q i PROPERTY LINE
RUBBER FENDER STRIP SEE FIGURE 7 SSH SN FLOATING DOCK SEE FIGURES 5 & 6 S y OCU KWIGUK PASS (YUKON RIVER)
BULLRAIL
1M = 10° FIGURE 3
CITY OF EMMONAK
Vg \ DOCK CONCEPTUAL DESIGN LCMF Incorporated / \ AVOUTIELAN
A subsidiary of Ukpeagvik Ifupiat Corporation 3 EMMONAK, ALASKA
Anch . Alask 907) 562-1830 \eigmemme y Borrow, “Alaska {302 a: DATE: 1/31/2000 | DRAWN BY: KK SHEET:
SCALE: 1” = 10’ | CHECKED BY: MPM W.O. No: 99-049
CATWALK
OPTIONAL STEEL REINFORCED
STAIRS CONCRETE DEADMAN/RAMP
EXISTING ARMOR STONE
CATWALK LANDING 6.0We riulTING vaic: 01/31/00 (16:14) CITY OF EMMONAK
: DOCK CONCEPTUAL DESIGN LCMF Incorporated / CAT wii [LANDING
A subsidiary of Ukpeagvik Iiupiat Corporation EMMONAK, ALASKA
Anchi » Alask 907) 562-1830 hes ee y Barrow, Alaska {s07) ss2-c712 DATE: 1/31/2000 | DRAWN BY: EBL
SCALE: 1” = 3’ CHECKED BY: MPM AUTO une URAWING serwnE: O4
FUUITING vaic: 01/31/00 (16:15) AUTOunu uRAWING wamE: O49—r 7.UWG
— FOAM FILL
vi
FOAM FILLED
12 GA ALUMINUM
CULVERT, WITH
END CAP, (TYPICAL)
PIPE PONTOON DOCK raz
Sc
FOAM FILL
" c= HIGH STENGTH
CONCRETE WITH
WIRE MESH
REINFORCEMENT
6x6 GROUNDING
BOARD
FIGURE 5
CITY OF EMMONAK KIN DOCK CONCEPTUAL DESIGN LCMF Incorporated /y ALTERNATE FLOAT SECTIONS A subsidiary of Ukpeagvik Ifupiat Corporation \ EMMONAK, ALASKA
Anch , Alask 907) 562-1830 \Wigeetns Barrow, ‘Alosko {367} 3e5-288o ‘ee DATE: 1/31/00 | DRAWN BY: KK SHEET:
j SCALE: 1” = 2’ CHECKED BY: MPM W.O. No: 99-049 SS
4" ALUMINUM
BULLRAIL, 8” ABOVE DECK
Poedrevpersere
\ RuBBER FENDER
CATWALK
ALUMINUM CLEAT
4°x4” ALUMINUM ALUMINUM TUBE. RAIL
DECK
RUBBER FENDER
ALUMINUM SHELL OF CONTINUOUS WELDED 12” C—CHANNEL
DOCK - SECTION VIEW =2 1 FIGURE 6
CITY OF EMMONAK
DOCK CONCEPTUAL DESIGN LCMF Incorporated pes DETAiLe
A subsidiary of Ukpeagvik Ifiupiat Corporation EMMONAK, ALASKA
Anchorage, Alaska (307 562-1830 Borrow, Alaska 907) 852-8212 DATE: 2/15/2000 | DRAWN BY: EBL SHEET:
SCALE: 1” = CHECKED BY: MPM W.O. No: 99049 AUluenu ORAWING NAME: 049-F4—6.DWG PLUTTING DATE: 02/15/00 (15:36)
ALUMINUM DECKING eiednt | WITH NON-SLIP
SURFACE: ALUMINUM J ~~, RAL SUPPORT
"D” SHAPED
BUMPER
BOLT
BOAT GUNWALE
2 LB/CF URETHANE FOAM MOLDED ELASTIC BUMPER DETAIL
SCALE: 1” = 1°
FIGURE 7
CITY OF EMMONAK
DOCK CONCEPTUAL DESIGN LCMF Incorporated SET ka
A subsidiary of Ukpeagvik Iffupiat Corporation EMMONAK, ALASKA
Anchi , Alask 907) 562-1830 Borrow, Alaska Bon} esuanis DATE: 2/15/2000 | DRAWN BY: DAR SHEET:
SCALE: AS SHOWN | CHECKED BY: MPM W.O. No: 99-049 AUTOCAD DRAWING NAME: 049-BUMP.DWG PLOTTING DATE: 02/15/00 (14:29)