Project Tag: ROV Operations

Guam Outfall Diffuser Installation

Global was subcontracted by Healy Tibbitts Builders (HTB) to install a new outfall and diffusers for the Guam Waterworks Authority as an upgrade of the treatment plant’s existing high density polyethylene (HDPE) outfall pipe. The outfall pipe is located in the Philippine Sea, approximately 2,000 feet offshore at an approximate depth of 140 FSW. The …

Potential HAZMAT Barrel Recovery

In late 2018, a team of recreational divers discovered several barrels at the bottom of the lake, some bearing labels of herbicides 2,4,5-T and 2,4-D; the combination of which is commonly known as “Agent Orange”. As the lake supplies drinking water to the town of Joseph, OR, authorities determined the barrels needed to be inspected …

ROV Recovery of Sunken Tug Samantha J

The 35’ steel-hull tug Samantha J sank in the Northumberland Channel near Nanaimo, BC in 2014 after she was overcome by the barge she was towing. The vessel sank in 230 feet of water and remained submerged for 4 years with hundreds of gallons of fuel oil, engine oil and hydraulic oil on board. Recurring …

Marine Outfall ROV Inspection

The Brightwater Marine Outfall was constructed and deployed in 2008 and came online in September 2012. Shortly after leaving the shoreline near Point Wells, WA, the pipeline branches into two parallel 84” HDPE outfall pipelines; diffuser ports are located on the last 250 linear feet of each pipe along with steel access gate structures. Semi-annual …

Global Uses ROV to Recover UW “Sea Spider”

Global was contacted by representatives of the Applied Physics Lab at the University of Washington regarding recovery of an instrument platform known as a “Sea Spider”. The instrument platform is used to gather scientific data from its resting point on the ocean floor, measuring currents, vessel wake, noise and other data; it also monitors fish …

Cornell Lake Source Cooling Intake Cleaning

The project involved anchoring a sectional barge in 250′ of water on an inland lake,and recovering an intake screen weighing over 4 tons to the surface for cleaning and inspection. With the screen off,cleaning pigs (3) were sent through nearly 2 miles of 62″ diameter pipe to clean accumulated quagga and zebra mussels.

There was miscellaneous work at the inshore Heat Exchange Facility building removing and installing large blind flanges to allow the pigging operation to take place. These flanges weighed up to 5700 pounds,with work taking place in a wet well 35′ deep.

ROV Assisted Derelict Fishing Net Removal

Over 5,600 derelict fishing nets had been removed from Puget Sound water by volunteer divers from depths up to 105 feet. Yet there remains many more in deeper water. Global Diving,working with Natural Resources Consultants for the Northwest Straits Foundation developed custom tooling and a ‘plan’ to remove the nets using a SAAB Cougar and Falcon ROV. First the ROV’s surveyed the nets,then a plan was developed,utilizing the tooling to gather and cut the nets free from the obstacles they snagged on. Once gathered and free,they were connected to the line from a vessel mounted crane. The balls of net were raised to the surface for proper disposal.

This pilot program was developed to test the feasibility and develop the tools and methods required for this removal.

Kaho’olawe Beacon Recovery Operations

Provide ROV and crew including sonar and CP probe to inspect approximately 25 items (targets) in 450 FSW off of the Hawaiian Islands. The inspection will provide updated positioning and depth of the items and provide a record of their current condition.

SS Montebello ROV Assessment

Global Diving and Salvage Inc. has been contracted by the United States Coast Guard to determine if oil is present aboard the sunken ship S.S. Montebello,which sits 900 feet below the ocean surface approximately 6.5 miles off the coast of Cambria,California.

The S.S. Montebello sank after a Japanese submarine torpedoed the large oil tanker on December 23,1941. The vessel broke apart landing upright with her bow separated from the majority of the wreckage. To date,no signs of leakage have been detected,and from previous visual inspections by submarine,the cargo section appears to be intact.

The possibility of future oil release has prompted the U.S. Coast Guard to contract Global to determine the integrity of the cargo section and its contents. Coast Guard Capt. Roger Laferrier,acting as the Federal On-Scene Coordinator,states,“The California coast is a vital national resource that we must protect.” Additionally,he explains,“Working in concert with our state and local partners,it is our duty to ensure we gain good information about the Montebello so we can do our best to protect the marine environment.”

Global’s Cougar XT ROV will be used as the platform which will support the inspection,both visual and sonar,thickness gauging,backscatter tooling operations,physical sampling of the tank contents,and sediment sampling from the general area. Global has teamed with T & T Bisso to provide engineering support and 3D modeling on the vessel. Additionally,Tracerco has been subcontracted to utilize their neutron backscatter tool,a non-invasive sensing device,which will be used to determine the presence of oil and oil/water interface.

“This sampling and observation operation will provide the answers needed to truly assess what threat,if any,the Montebello poses,” said Capt. Chris Graff from California Department of Fish and Game’s Office of Spill Prevention and Response,who will be serving as the State On-Scene Coordinator.

“Global Diving & Salvage is pleased to work in collaboration with the United States Coast Guard,other federal and state agencies,and our teaming partners to assist in the assessment of the vessel in a safe and efficient manner” says Devon Grennan,President of Global Diving & Salvage,Inc. “The project provides a unique opportunity to take a proactive approach towards mitigating potential pollution threats,and Global is proud to be a part of it.”

Seawater Intake Lines – Modification & Cleaning

Global Diving & Salvage,Inc was the prime contractor / project manager responsible for the modification and cleaning of the SeaLife Center’s intake lines. The first phase of the project was to install a pig launcher system; tasks included dewatering the Center’s wet well,installing an isolation valve between the well’s chambers,and saw cutting new access holes in the pump room floor.

The second phase of the project consisted of the dive crew cutting a 24 inch HDPE pipe and lifting it out of the soft bottom material to allow for an ROV inspection of the intake pipe. The inspection was short lived as the pipe was impassable due to marine growth and sediment. In order to clean the lines,several cleaning pigs were launched to remove the blockage. A new intake screen and support structure was installed along with a remotely operated pig catcher.

Dive crews worked off of a barge with a 150 ton crane and four point mooring system that was strategically anchored over the buried intake support functions. A deep gas dive system was utilized to accommodate dive operations in up to 260′ of seawater. The final quality control inspection was performed by an ROV flying over 200′ up the pipe to inspect for marine growth and debris.