Project Tag: Dive Support Vessel (DSV)

Seattle T-46 Barge Refloat & Fender Piling Repair Project

Seattle’s most extensive current civil works project,the Alaskan Way Viaduct replacement tunnel,is being constructed using the world’s largest tunnel boring machine ‘Bertha’. Due to the proximity of the construction site to the waterfront,the dirt and rock spoils from this effort are transported via conveyor belt to Pier 46. From there it is loaded onto barges for further transport.

Progress was recently halted due to an incident involving a spoils barge and a badly damaged pier.

In the early morning hours,the barge being utilized began to list and then capsize. Tunneling operations were halted due to the partially capsized barge at the adjacent pier and an impending rising tide.

The tunnel project personnel called Global’s 24 hour number to request immediate assistance. Global dispatched a Salvage Master who was on scene within 30 minutes of the call.

Following the removal of the unstable barge from underneath the pier,Global commenced a full salvage assessment. This included analysis of the barge’s stability and an underwater survey. The spoils had shifted on the barge causing it to list heavily to one side. Global developed a lightering plan and engaged a crane barge with a clamshell bucket to transfer the loose spoils to another barge.

As a precaution,Global positioned high capacity pumping equipment on location. Draft measurements monitored throughout the lightering indicated the presence of an unbalanced load in the barge. During the operations significant damage to the barge was observed. This information was incorporated into the lightering plan to ensure the safety of the operation. Following the lightering procedure,Global removed the damaged bin rails and prepared the barge for transit through the Ballard Locks.

The pier sustained significant damage to the fender piling from the capsizing barge. Global’s team quickly developed and proposed a repair plan. Following approval,Global removed the damaged piling and drove new steel replacements.

Additionally,it was determined a new fender system was required before loading operations could resume. Global’s team designed and installed an approved fender system allowing the project to continue tunneling operations.

Global provided salvage,environmental,and marine construction services to expedite and safely resolve this unexpected incident.

Salvage of Yacht Destroyed By Fire in Roche Harbor

In the morning hours of July 10,2013,while moored at a dock in Roche Harbor Marina in the San Juan Islands,a newly built 85’ motor yacht caught fire and burned. Firefighting efforts ensued however the vessel sank at her mooring. Responders deployed oil containment boom around the scene which has been very effective in containing debris and fuel from the vessel.

Global Diving & Salvage,Inc.,under contract to the yacht’s owner,mobilized personnel and resources from its Seattle headquarters and Anacortes operations to respond to the incident,conducted an underwater survey of the vessel and mitigated the environmental threat posed by the vessel. Global’s Marine Casualty Response group developed a salvage plan which was approved by the State and Federal agencies overseeing the incident.

Global contracted Manson Construction to provide crane lifting services utilizing specialized salvage rigging equipment designed and maintained by Global. A wide range of emergency response equipment is maintained by Global on 24 hour standby in the Seattle warehouse and other regional bases.

Under direction of Global’s Salvage Master diver’s rigged the hull of the yacht,which was raised from the seafloor and returned to a floating condition. Crews removed the remaining fuel and HAZMAT,it is inspected and deemed safe. The vessel was towed to a boatyard where it was removed from the water.

F/V Deep Sea Removed from Penn Cove

The 140-foot F/V Deep Sea was moored illegally off of Whidbey Island in Penn Cove,a world renowned oyster and mussel rearing area. On May 12,2012 it caught fire and sank,at the time of sinking there was no idea of how much fuel was onboard. Estimates ranged from 100 to 5,000 gallons,with a know capacity of 30,000 gallons.

Divers responded to plug the vents and keep the oil from entering the environment and contaminating the over 2,000,000 pounds of mussels,clams,and oysters that are raised in the cove. Containment boom was deployed and the leaking oil was contained.

The Department of Ecology and the Coast Guard agreed that the wreck must be removed from this natural habitat. Global Diving & Salvage,Inc. was contracted to perform the removal operation.

Two derrick barges were brought in to perform the lift,once at the surface the F/V Deep Sea was pumped out and refloated.

Hydrogen Reactor Salvage

On December 9th,a 485 ton,140 foot long stainless steel reactor vessel rolled off a barge into approximately 60 feet of water off Cherry Point,WA. One end rested on the sea floor,with the other end,just breaking the surface. Immediately after the incident,Global provided an ROV to inspect the vessel for damage and asses its orientation on bottom. It was determined that there was no structural damage.

Global was contracted to develop,implement and manage the salvage. Over the next two weeks,working closely with the engineers and the owner,a detailed salvage plan was developed to safely lift the reactor from the water and deliver it back to the owner aboard a barge into cradles that were mounted to a transporter for offloading and movement to its final location. Two marine construction companies,General Construction and Manson Construction provided heavy lift derrick barges to lift the reactor and set it back onto the barge.

Divers were utilized to perform a thorough inspection of the structure as well as expose the lifting eye on the bottom edge of the vessel. When all of the plans had been approved and the required assets were in place,divers connected a 400 ton shackle to the lifting eye. The derrick barges,working in tandem at the direction of David DeVilbiss,Salvage Master for Global Diving & Salvage,Inc,lifted the reactor to the surface. It was raised out of the water,the barge positioned underneath and set into the cradles on the transporter.

The reactor is a integral piece of a refinery upgrade,assisting in the manufacture of low sulfur diesel fuel. The vessel was filled with nitrogen to prevent corrosion during transportation.

Lift Bags Raise Sound Developer Derelict

The Sound Developer was an ex-US Navy landing craft that was 132 feet long overall. She had a beam of 29 feet and a normal draft of 5 feet. The US government sold the vessel at auction and the ship passed through several owners before falling into neglect which ultimately ended with the derelict sinking at her moorings in the harbor at Cordova,Alaska in august of 2009.

Shortly after the sinking the US Coast Guard activated Global Diving & Salvage through the established Basic Ordering Agreement (BOA) contract. Global mobilized resources to Cordova where the pollution threat was mitigated through the removal of the copious oil filled containers,batteries and other HAZMAT. The US Coast Guard then worked through a nearly 2 year long process seeking Headquarters approval to refloat the vessel,transport it to shore and deliver it to the City of Cordova for dismantling and disposal.

Upon receipt of approval the US Coast Guard solicited competitive bids to affect the recovery. Through this process Global was contracted by the USCG to remove the pollution and navigation threat from the Harbor,move it to an area onshore outside of the harbor and perform gross decontamination of the vessel.

Due to the remoteness of the location,no heavy lift assets were available. A plan was developed to utilize lift bags to raise the vessel,secure it for the short tow out of the harbor to the designated shore position.

Divers secured a total of 31 lift bags that were used to raise the vessel: 24 – nine ton; 5 – five ton and 2 – twenty two ton bags. The lift bags were strategically placed and secured to the hull.

All the lift bags were connected to a manifold,from which all inflation / deflation operations were carried out under the supervision and at the direction of the salvage master.

Once afloat the bags were further secured to the vessel and made ready for the open water tow to the beaching area outside the harbor. The vessel was placed aground at high tide and was shifted further ashore through subsequent tide cycles.

The operation was timed to coincide with the highest tides of the season to ensure it would be brought on shore as high up the beach as possible. This phase of the operation was complicated by extremely challenging weather conditions that impacted the schedule and the work conditions.

Once the Sound Developer was safely secured on shore,Global conducted further cleaning and gross decontamination. The vessel was inspected and cleared by on scene US Coast Guard personnel and custody of the vessel was transferred to the City of Cordova.

Pipeline Abandonment

Global mobilized a four point mooring system and a deep air diving system onto a landing craft. The vessel was then moored 40ft from the leg of a production platform and directly over a sub sea oil and gas manifold. This required anchor operations to conducted in 3 pipeline corridors and near an active production platform. The project involved installing several hot tap installations and disassembling and re-assembling various spool pieces of the subsea manifold,which aid in the ability to utilitize cleaning pigs in both lines from the platform. All this was done without interrupting flow thought the manifold or operations on the production platform that it is connected to. This project was performed in Cook Inlet that is typical has zero visibility and tidal current in the excess of six knots

Manette Bridge Replacement Project – Sheetpile Cutoff

The Manette Bridge Replacement Project is a large WSDOT construction project to replace the aging 80yr. old Manette Bridge during a year-and-half-long project with contractors Manson and Mowat. Construction began in August of 2010 and is scheduled to conclude in early-2012. It will improve travel across the Port Washington Narrows by adding shoulders,widening the pedestrian walkway,and constructing a new roundabout in Manette.

Crescent City – Tsunami Response

On March 11th,2011 after the 8.9 magnitude earthquake in Japan a tsunami wave crossed the Pacific Ocean landing squarely in Crescent City,California. Our crews were activated by the US Coast Guard to provide environmental and diving services necessary to address the immediate pollution threat caused by the tsunami,which damaged 30 vessels in the Crescent City Inner Harbor on the coast of Northern California.

Our initial response was directed to contain fuel which had already leaked from the various vessels,as well as to prevent fuels and oils on-board from further release. The initial dive tasks focused on surveying the wreckage and addressing the pollutants. During the survey,it was observed that several of the sunken wrecks were piled on top of each other,making it unsafe for divers to access points of release and fully seal leaks. Divers were able to seal exposed ports and remove fuel from the tanks of vessels they could access.

To safely remove the unstable vessels a derrick barge was brought in from San Francisco. Divers used straps and slings to rig the larger,more intact sunken wrecks to lift them from the water A clam bucket was used grip the smaller and more severely damaged vessels. All wrecks were transported to shore for proper upland disposal.

In all 10 sunken vessels were removed from the Inner Harbor. Over 400 gallons of fuel and oily waste were contained and properly disposed of.

T-18 North Harbor Island Mooring Dolphins

Provided on-call dive support for the removal of four dilapidated timber mooring dolphins. Divers also assisted with the installation of steel dolphin replacement structures,including the installation of new structural steel members underwater. The installations included welding anodes onto the dolphins and securing plastic fenders.

Caisson Drydocking

Global Diving & Salvage provided two dive teams working from small DSV’s to assist with the drydocking of a graving dock caisson. The gate had never been drydocked before; special attention had to be paid to layout of blocking and installation of shims.