Archived Construction Updates (2004-05)

View GraphicProgress Map (3/21/05)

View Graphic: Inner Harbor Schematic

"Before and After" Photos of Ft. Macon

(see picture title for dates of photos)

Before - Bathhouse Stairs


Construction Notes:

3/21/05 (Final Update) - Marinex Construction completed inner harbor dredging maintenance activities with concurrent beach placement last week and has begun the demobilization process. A graphic depiction of the beach nourishment ranges completed this year (inner harbor and Brandt Island) are provided in the progress map above. Also, Manson Construction completed all activities associated with outer harbor maintenance last week as well (offshore disposal) and have since mobilized to the Wilmington Harbor for maintenance dredging at this Navigation Project.

3/14/05 - Both maintenance dredging scopes of work in the inner harbor with concurrent beach placement (Marinex Construction), and the outer harbor with offshore disposal (Manson Construction) could be completed within the next week. Dike reconstruction along the outer rim of Brandt Island should be initiated sometime next week.

3/7/05 - Maintenance dredging of the inner harbor with concurrent beach placement continues (see progress map for beach nourishment placement area). Maintenance dredging activities are currently centered within the turning basin (see inner harbor schematic above).

2/28/05 – Maintenance dredging of the inner harbor with concurrent beach placement continues (see progress map for beach nourishment placement area). Dredging activities are currently located near the Beaufort Bridge and will be subsequently positioned within the turning basin (see inner harbor schematic above). Over 300,000 cubic yards have been dredged to date from the inner harbor and work should be completed within the next 3-4 weeks.

Also, Manson Construction initiated outer harbor dredging maintenance work with offshore disposal on 2/24/05 utilizing the Bayport, a 5,500 cubic yard capacity hopper dredge. Maintenance activities should take 10-14 days to complete (~300,000 cubic yards total). Manson has a single contract to complete both Morehead City and Wilmington Harbor scopes of work.

Dike reconstruction along the rim of Brandt Island should begin in a couple of weeks, utilizing an subcontractor contracted by Bean Stuyvesant.

2/21/05 – Maintenance dredging of the inner harbor with concurrent beach placement continues (see progress map for beach nourishment placement area). Dredging activities are currently centered within the turning basin (see inner harbor schematic above).

2/14/05 – Marinex Construction’s 18” cutterhead-suction dredge, Hampton Roads, completed the infilling of the pre-existing gap located near the Ft. Macon bathhouse, where sediments pumped from Brandt Island and the Inner Harbor merged. Maintenance dredging of the Inner Harbor continues and the sediments are currently being placed along the eastern half of the Ft. Macon State Park oceanfront (see progress map above). The Hampton Roads encountered a minor mechanical problem last week but maintenance dredging activities are are currently centered along the eastern flank of the turning basin (see inner harbor schematic above). It is estimated that maintenance dredging will take a month to conclude. Also, demobilization of land-based pipeline associated with the Brandt Island Pump-Out is progressing nicely.

2/7/05 – Bean Stuyvesant’s 30” cutterhead-suction dredge, the Meridian, departed the Morehead City Harbor last Monday (1/31/05) subsequent to completing the pump-out of Brandt Island the week prior. The Hampton Roads, Marinex Construction’s 18” cutterhead-suction dredge, is continuing bi-annual (every other year) maintenance dredging of the Inner Harbor and is currently positioned in Range C near the Jet Fuel Storage Tanks located on Radio Island (see Inner Harbor schematic above). The shoal material encountered during maintenance of the Inner Harbor is transferred via submerged/buoyed/land pipeline to the shorelines of Fort Macon. The discharge is currently located near the 4-WD Ramp at the Ft. Macon bathhouse (~Station 9.5) and is dovetailing with the beachfill that emanated from the Brandt Island Pump-Out. The sediment grain size as of late has been finer than in previous weeks causing the fill to diffuse at gentler slope.

1/28/05 – Bean Stuyvesant completed the Brandt Island Pump-Out this past Tuesday morning (1/25/05) at approximately 4:00, and should begin dike reconstruction within the next several days. Approximately 2.8 million cubic yards were removed from the island and placed along the shorelines of Atlantic Beach and Ft. Macon in less than three months time. The last stages of beachfill activities progressed eastward from Commerce Way in Atlantic Beach and concluded at Station 9.6 in Ft. Macon (approximate).

Meanwhile, Marinex Construction is continuing maintenance dredging activities within the inner harbor with concurrent beach nourishment along Ft. Macon. The current discharge area is located at Station 8.6, at the Ft. Macon Bathhouse groyne – see pictures below and progress map above. The cutterhead-suction dredge, Hampton Roads has completed maintenance dredging of Bulkhead Channel and Range B near the cutoff and its intersection with Bulkhead Channel (see harbor schematic above). The Hampton Roads is currently dredging near the intersection of Ranges B and C. Sediment quality remains excellent (grain-size and aesthetics), and in all likelihood Marinex will close the nourishment gap near the Ft. Macon Bathhouse, dissemble pipe, and “thicken” the nourishment template within Ft. Macon; again working east to west.

1/24/05 – Bean Stuyvesant’s 30” cutterhead-suction dredge, the Meridian, could complete the Brandt Island pump-out tomorrow (~2.8 million cubic yards total) with the sediment discharge emanating from the latter stage of this effort located at ~Station 9.6, just east of the Atlantic Beach/Ft. Macon State Park boundary. Final surveys and dike reconstruction within Brandt Island could begin later this week.

Also, Marinex Construction’s 18” cutterhead-suction dredge, the Hampton Roads, is currently situated in the northern half of Bulkhead Channel (see inner harbor schematic above). As mentioned in previous updates, the shoal material encountered during maintenance dredging is transferred via a buoy/land pipeline run to Ft. Macon with the discharge initiating at Station 4.725 and progressing west. The discharge is currently positioned at Station 8.2 (see progress map above), which is located near the Ft. Macon swimming beach/groyne. Marinex could complete Bulkhead Channel later this week and continue dredging Range B prior to entering the Turning Basin.

Sediment quality has been good for the past week regarding aesthetics and grain-size from both Brandt Island and the Inner Harbor areas.

1/17/05 – The Hampton Roads (Marinex Construction) has recently entered Bulkhead Channel and progressing northward from its intersection with Range B in the Inner Harbor (see inner harbor schematic above). The shoal material encountered during maintenance dredging is transferred via a buoy/land pipeline run to Ft. Macon with the discharge initiating at Station 4.725 and progressing west. The discharge is currently positioned at Station 6.7 (see progress map above). The Hampton Roads is undergoing minor repairs that emanated from a mechanical breakdown that occurred this past weekend. The repairs should be completed today.

The Meridian (Bean Stuyvesant) was under repair for a majority of the past two weeks and re-initiated the pump-out of Brandt Island this past Saturday (1/15/05). The discharge is located at Station 12.1 in Atlantic Beach near Commerce Way and will progress east to link with the Hampton Roads beach nourishment effort.

1/9/05 - (A) Marinex Construction’s 18” cutterhead suction dredge, the Hampton Roads, initiated inner harbor maintenance dredging with concurrent beach nourishment Friday evening (1/7/05). The Hampton Roads is currently located within Range B, near its connection with the Cutoff (see Inner Harbor graphic above). The beach nourishment reach will begin over 1,500 feet west of the terminal jetty at Ft. Macon (Sta. 4.725 on the progress map above) and progress westward towards the Ft. Macon Bath House. The sediment quality is excellent in terms of grain size and aesthetic appearance (see photos below).

(B) Bean Stuyvesant’s 30” cutterhead suction dredge, the Meridian, that has been dredging Brandt Island for the past two months has been down a majority of the past week for repairs. The discharge will now be diverted to the east from Commerce Way in Atlantic Beach to meet with the fill progressing westward from the Hampton Roadsdredge pipe extension. The westernmost point of the Brandt Island fill reached Sta. 28.6 (the western edge of Ocean Ridge), and there is a degree of uncertainty if any of the sand remaining in Brandt Island (600,000 cubic yards estimated volume) will be placed any further west than Sta. 28.6 (see progress map above).

Photo - Hampton Roads
Photo - Sand Quality

1/3/05 – Marinex Construction’s 18" cutterhead suction dredge, Hampton Roads, arrived to the Morehead City Harbor this past week to begin inner harbor channel maintenance dredging with concurrent beach nourishment extending from the Fort Macon jetty (Station 4.7) to Commerce Way in Atlantic Beach (Station 12.1). Although the schedule is tentative at this point, Marinex will likely dredge the Bulkhead Channel portion of the inner harbor before advancing to the inner harbor proper and the turning basin (see inner harbor map above). The Meridian, positioned in Brandt Island, is continuing to “pump-out” the material located in this upland disposal facility with the discharge point currently located at Station 27.9 (see progress map above). The material placed on the beach in the past dew days has been finer-grained than in weeks prior. This has hampered progress along the beach but there are no mud balls to report.

12/27/04 – Productivity has remained steady throughout the Christmas season with the discharge pipe currently positioned at Station 26.8, located in the heart of the Ocean Ridge subdivision (see progress map). It’s anticipated that the fill pumped from Brandt Island will reach the project’s end target, which is situated at Station 33.8 or ~500 east of the Sheraton Pier. In terms of distance, approximately 47% of the project has been completed to date. The remaining section extending from Ocean Ridge to the Sheraton Pier will be completed utilizing Brandt Island material, and the remaining reach extending from the Fort Macon terminal jetty to Commerce Way in Atlantic Beach will be completed utilizing inner harbor dredged material via a cutterhead-suction dredge (Marinex Construction).

12/17/04 – The Meridian has been operating all week and progress/productivity has been solid, averaging a few to several hundred linear feet per day. Correspondingly, sediment quality has also remained good with the current discharge point located at Station 24.2 with the next Y-valve positioned at Station 25.5, which has also been utilized during the addition of pipe on the active pipe reach stemming from Station 20.5 (see progress map).

12/12/04 – Productivity has been “good” in the past several days since the berm width has been narrowed for the Project coupled with the fact that the Meridian has been encountering coarser-grained material in Brandt Island that is also relatively free of mudballs and aesthetically more pleasing. The discharge area is currently located at Station 22.8 (see progress map), located just west of the Atlantic Beach Circle. Marinex Construction is now scheduled to begin inner harbor maintenance dredging/beach nourishment in early January.

Photo - Discharge Area

12/7/04 - As discussed in the previous updates, there appears to be just enough clay and fine-grained sediments in Brandt Island to cause the slurry to run down the beach without “dropping” the coarse-grained material along the construction template. The fine-grained material is more or less diffusing offshore and therefore the offshore slope of the fill is running at 1:50 to 1:60 (vertical :horizontal) for instance, rather than 1:20 or 1:25. This creates an excessively gentle offshore slope that requires an equally tremendous amount of material to achieve (see schematic). Thus, what was thought to only take ~70 cubic yards per linear feet (cy/ft) to complete is now consuming ~200 cy/ft to complete. Beach nourishment activities should have progressed westward well beyond the Circle in Atlantic Beach with the volume of sand dredged out of Brandt Island, but the distance filled to date is ~4,600 linear feet with well over 1,000,000 cubic yards pumped out of Brandt Island.

At this rate, we will simply not have enough material to construct the Section 933 Option for Pine Knoll Shores. Based on these set of circumstances, the Section 933 Project this year will not occur (see Corps’ press release). A stop work order has been issued to Bean Stuyvesant for the Section 933 Project. The berm width will also be reduced for the remainder of the project to maximize pumping distance with the hopes of reaching the westward end of Atlantic Beach.

While there are some mudballs along the beach along the corridor extending from Triple S to Oceanna piers (higher concentrations in some areas than others), they are resting on fine-grained sand or coarse-grained silt (i.e., fine-grained material). If the fill was all mud (silt and clay only), the material wouldn't settle along the beach and rather disperse into the Ocean. The dredging contractor would have pumped over a million cubic yards out of Brandt Island with no beachfill along the shoreline. That's not the case - the beach is extremely wide in between Triple S and Oceanna piers (see aerial photograph 11/30/04).

On a positive note, the sand pumped this past weekend just west of Sportsman's Pier was essentially free of clay with a more brown/tan hue to the slurry, and is more aesthetically pleasing. However, the slurry remains fine-grained and the slope problem still remains an issue and would plague our efforts if the fill was scheduled to be pumped into Pine Knoll Shores.

Also, Marinex Construction is scheduled to arrive at the Inner Harbor to begin maintenance work with beach placement on December 15th – 18th. The fill is planned to cover the area extending from the terminal jetty at Fort Macon westward to Commerce Way in Atlantic Beach.

11/28/04 – The Meridian has pumped continuously during the past week. The fine-grained material remains an issue by causing the slurry to cascade down the beach without “dropping” the coarser-grained material. This requires more sand to be utilized to complete the berm template designed for the project. The situation is being monitored closely.

11/22/04 – The relatively minor amounts of mud in Brandt Island, when mixed with sand and water, is essentially lowering the slurry’s ability to drop the coarser-grained material on the beach when pumped. The slurry is cascading down the beach without depositing the volume of sand expected and therefore has dampened the project’s progress along the beach. The pump-out is in the infantile stages however, and hopefully beach construction productivity will improve.

11/15/04 – After a few days of pumping, the Meridian encountered a couple of mechanical problems and did not operate through a majority of the past weekend. Dredging/pumping could resume sometime this evening. Approximately 1,300 linear feet of the beach has been constructed (see progress map).

11/10/04 – Bean Stuyvesant’s cutterhead-suction dredge, the Meridian, encountered a mechanical problem with the anchoring mechanism just hours after initiating the Brandt Island Pump-Out this past Sunday. The apparatus underwent repair, and pumping resumed today.

11/7/04 – Bean Stuyvesant’s cutterhead-suction dredge, the Meridian, began to cut through the dike wall leading into Brandt Island earlier this morning once the land-based pipeline along Commerce Way was completed. Bean is flushing the dredge pipes and working through any pipeline problems today. The actual dredging and pumping activity should be initiated later today, or early tomorrow. The full compliment of survey stakes and safety netting along the beach should also be installed later day, or early tomorrow. The beachfill will begin at Station 13.6 (see map above), or just west of Triple S, and progress westward into the center of Atlantic Beach and into Pine Knoll Shores.

11/1/04 – Bean Stuyvesant's cutterhead-suction dredge, the Meridian, arrived last week and is anchored along the eastern flank of the N.C. Port Authority complex. The submerged pipeline that will transition from the dredge to the land-based pipeline near the intersection of Commerce Way and Hwy 58 in Atlantic Beach should arrive to the harbor this week. Dredging and pumping activities should begin this weekend.

10/20/04 – The U.S. Army Corps of Engineers formally awarded the Section 933 option to Bean Stuyvesant last week. The estimated start date is 11/1/04.

 HOW TO INTERPRET THE PROGRESS MAP FOR PHASE II OF THE SECTION 933 PROJECT

Phase II of the Section 933 Project, or the “Pump-Out Phase” will utilize dredged shoal material from the inner harbor reach of the Morehead City Harbor Federal Navigation Channel for beach nourishment in two zones located along Bogue Banks. One zone is referred to the “Base Plan” and encompasses the shorelines of Fort Macon and Atlantic Beach (~26,000 feet excluding a 1,000 foot buffer at each pier). Beach nourishment in this area is a 100% cost to the Federal government. The second zone is a Federal/non-Federal cost-shared area encompassing a majority of the Pine Knoll Shores shoreline (~26,000 feet). This second zone simply constitutes Phase II of the Section 933 Project.

As mentioned above, the sand utilized for beach nourishment is dredged shoal material from the inner harbor. “Shoal material” is a term for sediments that fill the channel and are subsequently required to be dredged in order to maintain a minimum depth for cargo ships leaving and entering the Port of Morehead City. The inner harbor is dredged or “maintained” every other year and the sediments dredged from the channel are temporarily stored at the upland disposal facility of Brandt Island, located immediately NW of Fort Macon. Once Brandt Island becomes “full”, the shoal material is “pumped-out” to the beaches of Bogue Banks. This usually occurs on a decadal basis (every ten years). The maintenance material that is required to be dredged from the inner harbor in winter 2004-05 will be pumped directly to the beach rather than stored in Brandt Island.

The dredging contract has been awarded to Bean Stuyvesant and the cutterhead-suction dredge, the Meridian will be used to pump the sand from Brandt Island to the Base Plan and Section 933 zones of the beach. Marinex has been subcontracted by Bean Stuyvesant to complete the inner harbor maintenance work for 2004-05. A cutterhead-suction dredge utilizes a crane placed on a barge-type vessel that positions the cutterhead, which looks like a gigantic drill bit, along the seafloor. The cutterhead agitates the sandy bottom, and the resulting slurry of sediment and water is subsequently suctioned into a long tube transitioning into a pipeline that can be extended to a beach or disposal area.

An underground sleeve helps connects the pipeline extending from Brandt Island to the beach. The sleeve runs underneath Hwy 58 and towards the shore along Commerce Drive in Atlantic Beach. From this point, the pipeline will run eastward to complete the Fort Macon section of the project, then westward into Atlantic Beach and the Section 933 zone of Pine Knoll Shores. Booster pumps are required for the western leg of the pipeline extension because the distance associated with completing this reach overwhelms the capacity of the pumps located on the dredge. Without booster pumps, the transferal of sand from Brandt Island to the beach would become a slow and inefficient process. Once the slurry of sand and water begins reaching the shore, the material is bulldozed into general construction specifications for subsequent grading into final contours, tilled, and opened for recreational use.

Project engineers use “stations” positioned along the beach to track nourishment projects and to verify in-place volumes of sand placed on the beach by dredging contractors. The stations for the Brandt Island Pump-Out/Section 933 Project are provided in intervals of five in the figure above. These station numbers and the tick marks in between conveniently correspond to linear feet along the beach. For instance, the distance between station “40” and “45” on the figure above is approximately 5,000 feet. The distance from station “25” to tick mark “24”, located immediately east, is approximately 1,000 feet. If you visit the beaches of eastern Bogue Banks this winter you may see wood or metal stakes at the base of the dunes that will identify these station numbers that will enable all of us to keep track of the construction progress.

The “area of detail” figure provides a detailed view of the Base Plan and Section 933 zones to be completed in the winter of 2004-05 with station numbers and the general location of the land-based discharge pipeline. The shaded areas in red represent the completed portions of the project and will be updated on a weekly basis throughout the construction.