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HomeMy WebLinkAboutCity of Akhiok Fuel & Supply Dock Feasibility Study& Preliminary Design 199104-40 1 CITY OF AKHIOK FUEL AND SUPPLY DOCK FEASIBILITY STUDY AND PRELIMINARY DESIGN Prepared For: CITY OF AKHIOK Prepared By: R&M CONSULTANTS, INC. 5024 Cordova Street Anchorage, Alaska 99503 APRIL 1991 TABLE OF CONTENTS I. INTRODUCTION II. GENERAL DESCRIPTION III. SITE VISIT IV. SITE SELECTION AND CONCEPT DESIGN Vv. PROPOSED DESIGN OPTIONS VI. PROJECT COSTS APPENDIX FIGURE 1 FIGURE 2 FIGURE 3 04-40 2 © OF WN PB community leaders. The village is situated on treeless, gently rolling terrain along the northwest shore of Akhiok Bay. The proposed location for a new dock is at Pryor (Prior) Point, approximately 1.5 miles southwest of the village. This is the western-most point of a narrow strip of land between two bodies of water, where Kempff Bay and Akhiok Bay meet. A road connects the village with Pryor Point where the community's tank farm is located. The local airfield is also located on the strip of land between the Point and the village. The tank farm at Pryor Point has a total storage capacity of about 43,000 gallons of diesel fuel in six tanks of equal size. There is no gasoline stored at Akhiok. The tanks are located very near the beach within an earthen containment dike. The tanks are currently filled once annually by barge. Existing storage barely meets current demand and the village has had to purchase fuel from the school's reserve supply. The school separately maintains four tanks in reserve with a total capacity of about 14,000 gallons located near the teacher housing in the village. The school tanks are un-diked and appear to be in poor condition. It is anticipated the school would decommission these tanks if the village increases its storage capacity. Akhiok's estimated fuel storage requirement is 60,000 gallons of diesel and 10,000 gallons of gasoline based on present consumption and with a small allowance for growth. However, if the village were able to develop a market to fuel fishing vessels, the requirement for diesel could be as high as 160,000 gallons. The proposed dock, fuel consumption and distribution, and the economic stability of the community are, therefore, closely linked. The existing tank farm is located on property owned by Akhiok- Kaguyak, Inc., the local village corporation. The Corporation is 04-40 2 ~~ reportedly transferring ownership of two acres (the tank farm site) and an easement to the road to the Village of Akhiok. Lewis anticipated that the Corporation would cooperate in transferring to the village any reasonable amount of land required for construction of a new dock. III. SITE VISIT On November 17-18, 1990, Mr. James Allen, representing R&M Consultants, visited Akhiok to meet with community leaders and other interested parties to discuss the proposed dock and to look at available sites for the structure. During his visit, Mr. Allen met with three City Council members: Judy Simeonoff, Renna Cohen, and Linda Amoto. Judy Simeonoff is also the Mayor. Mitchell Simeonoff accompanied Jim Allen to the Pryor Point site, which is generally the preferred area for the proposed facility. At Pryor Point three locations were examined for the structure: a Immediately adjacent to the tank farm where the earlier floating dock had been. 2s Five-hundred yards east of the first site. Bi On the north side of Pryor Point, near the tank farm. The beach and bottom conditions were similar at the three sites, and appeared to consist of coarse, gravelly sand with some rocks and rock outcrops. It could not be determined if piling could be driven at this location. Piling have been driven at the Ward's Cove plant at nearby Alitak, however, the distance between these two points is too great to make any correlation. Residents at Akhiok reported that Pryor Point is fairly well sheltered and that the highest observed waves are in the range of 04-40 3 -3- 3-5 feet. We were informed that the strongest winds occur during the winter, come from the northeast and the northwest, and are estimated not to exceed 85 knots. During summer the most severe winds are less than 40 knots, and come from the southeast. The water around Pryor Point has been known to occasionally freeze during extremely cold winters. It was determined that the village owns a gravel source which could be used for construction of a dock or dock access road. However, the village has never sold any gravel, and therefore could not place a price on the material at this time. The only heavy equipment available in Akhiok consists of: (1) 3/4 ton pickup truck, (1) JD 450 crawler, (1) JD 480 loader, and (1) motor grader (owned by the State). We subsequently learned that Ward's Cove Packing Company has a barge-mounted pile driver at Alitak. Iv. SITE SELECTION AND CONCEPT DESIGN Site Number 1 This appears to be the least costly site to develop due to its proximity to the existing tank farm and access road. This minimizes piping costs between a future dock and the tankage, and it is near land presently being legally transferred to the village for the fuel storage area and easement to the existing road. Little additional property would be required for dock development at this site. This is also the same location where the previous floating dock was constructed. All obstructions to low water were reportedly removed as part of that work. Therefore, less bottom preparation may be required here than at the other two locations. This site is less sheltered than the others, but provides more vessel maneuvering space. 04-40 4 -4- Site Number 2 Site No. 2 is 1,500 feet east of Site No. 1. It will require about 600 feet of additional road construction, and 1,500 feet of additional fuel pipeline. Although more protected from wind than Site No. 1, there is a nearby shallow reef and less vessel maneuvering room; both are potential hazards. More property would have to be acquired at this location compared to Site No. 1. Site Number 3 Located 300 feet north of Site No. 1, this site has problems similar to Site No. 2, but to a lesser degree. Only about 300 feet of additional new road and pipeline construction would be required. Property acquisition requirements would likewise be less. Site No. 3 is the most sheltered of the three, but limited vessel maneuvering room and a shallow reef present hazards not present at the first site. Tidelands In the event that Akhiok does not possess a tidelands lease for the area proposed for the new dock it will be necessary to obtain one from the State. This can be a lengthy process -- up to a year or more -- and the village may wish to begin this activity in the very near future. Dock Concepts The primary function for a new dock or moorage at Akhiok will be to off-load fuel barges. Additionally, it is expected that a new dock will be used for fueling and servicing of locally owned fishing vessels during the summer months. There are no boats berthed in Akhiok during the off-season due to the lack of adequate shelter, and since the proposed development will not improve that condition, 04-40 5 -5- we do not anticipate any related modification. However, once a secure moorage is developed it may offer opportunities for the development small businesses such as a fuel service for fishing vessels. It may also lead to a demand for water borne transportation of goods currently being handled by alternative and more costly methods, as well as for goods and services currently unavailable because there is no dock. With those things in mind, R&M developed two concepts for the proposed facilities, either of which work at all three sites. Site Number 1 is the preferred location for the reasons outlined above, but until a detailed underwater inspection and geotechnical investigation is conducted the choice is tentative. For concept, we selected designs that lent themselves to a phased program in which portions of the dock can be constructed as funds become available. In establishing design criteria for the dock we spoke with Pacific Alaska Fuel Services, Inc. (Seattle, WA) and Flyum's Barge Service, Inc (Homer, AK), in additional to gathering local input. Pacific Alaska Fuel Services uses 1300 long ton barges that measure approximately 50 x 160 feet with a 8 foot draft. fFlyum's Barge Services uses three different vessels: a 90 foot tow barge, a 120 foot motorized barge, and a 140 foot motorized barge, all of which draft 5-6 feet. A minimum of 2 foot additional depth should be provided beneath the maximum design vessel, or in this case, a total depth of about 10 feet. The recommended minimum bottom elevation adjacent to the dock is therefore about -13 feet mean-lower-low-water. This will provide the greatest utility and prevent vessels from having to "work the tides", which at Akhiok have a diurnal range of about 12 feet. It is proposed that vessels (barges) dock parallel to shore to minimize the cost. Since cargo handling is not the primary function of this facility, there is no requirement to develop a 04-40 6 -6- long working (outboard) face on the dock. Therefore, we recommend that two combination mooring/breasting dolphins be used to fender and hold vessels in place. These need to be sized and positioned to accommodate the range of vessels expected. In addition, an access trestle from the shore to the vessel is needed to carry pipelines (or hoses), personnel and possibly a light vehicle. In addition to fuel barges, the facility should be capable of simultaneously mooring three or four 30-foot fishing vessels. A fuel-dispensing berth is also suggested, but fueling need not be concurrent with mooring a barge. Finally, a small, gravel surfaced uplands area of approximately 10,000 square feet will be required for staging. Until geotechnical investigations are carried out at the site, there are several unknowns’ regarding suitable methods’ for constructing the proposed facilities. Our primary concern is the potential for shallow bedrock which could complicate the design of piling needed to resist vessel berthing and mooring forces. These lateral loads develop tensile (pullout) forces in certain piling which become difficult to resist when penetration is shallow. There are a number of solutions available, such as finned piling, increasing the number of piling, increasing the batter on piling, and anchoring the piling into the rock, among. others. Unfortunately they all result in higher costs. The construction estimate in Section V. is based conservatively on shallow bed rock conditions and the need to socket, or tendon the piling. V. PROPOSED DESIGN OPTIONS It is proposed that initial construction consist of two dolphins and a narrow trestle from shore out to the berth which is oriented parallel to shore (see Figure 1). Two options have been considered for the dolphins: 1.) steel 04-40 7 ips structures consisting of a "king pile" with two batter piles and vertical, cylindrical rubber bumpers attached to the outboard face of the king piles (see Figure 2). The king piles also act as bollards for attaching mooring lines. These function as both, mooring and breasting dolphins and hold large vessels away from the trestle and future dock. 2.) 7-pile clusters using timber piling wrapped with wire rope at the top (see Figure 2). The center pile would provide a point of attachment for mooring lines. No bumpers are required on this type of dolphin which relies on the group- action of the piles in bending to absorb berthing and mooring forces. It is recommended that the trestle be constructed of all steel pile bents and prestressed concrete deck panels. In the initial phase the deck is one panel wide (4 feet) and spans 50 feet between pile bents. However, the bents will be wide enough to accept two or three future panels resulting in an overall width of 12-16 feet. Additional bents will be required in the future to reduce the spans for loadings greater than foot traffic, but even then loads are not anticipated to be very heavy. In addition to widening the approach, in the second phase a 25-foot x 52-foot dock will be created at the end of the trestle. Its construction will be similar to the trestle. It may be advisable in the future to create a more secure moorage for larger vessels by providing onshore mooring points for bow and stern lines; these might be stake piles or concrete gravity anchors. However, given the frequency and duration of berthing for vessels currently visiting this site the proposed mooring arrangement will be adequate except under high wind and wave conditions, at which point it may be necessary to pull away from the berth and anchor in deeper water. This is not an unreasonable situation. 04-40 8 -8- VI. PROJECT COSTS The estimated project costs, in 1991 dollars by phase (see Figures 1 and 2) are: Phase I Phase II - Construction $515,000 $450,000 (includes 15% contingency) - Design 50,000 35,000 - Design Survey* 8,000 - Tidelands Lease (including 15,000 survey) - Corps of Engineers Permit 3,000 3,000 - Geotechnical Investigation 65,000 . - Construction Administration 20,000 15,000 - Grant Administration 3,000 3,000 Administration TOTAL $679,000 $506,000 * It may be possible to combine the design and tidelands surveys which will reduce costs by about $4,000.00. If Phases I and II are combined, we estimate the total project cost to be $1,150,000.00, or a savings of about $35,000.00 compared to doing the project in separate contracts. 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