Underwater Pipelines

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Pipeline Inspection

Logan Diving & Salvage has been performing hydrographic surveys of navigable river crossings since the 1950s. Inspection is two parts consisting of an electronic hydrographic survey and physical diver underwater inspection.

U.S. Department of Transportation (D.O.T.) river crossing surveys have been accomplished by Logan Diving & Salvage in virtually every navigable body of water east of the Mississippi river. Logan Diving & Salvage personnel are Operator Qualified (OQ) to work on pipelines underwater. We are members of both Operators Qualifications Solutions Group (OQSG) and ISnetWorld.

Hydrographic survey results provide data to produce accurate plan and profile drawings for comparison over the years. These profiles document streambed/ground line changes and help clients maintain their crossings.

Commercial diver inspection is accomplished to ensure the subject pipeline is buried throughout the entire crossing and or to identify exposure and defects. If exposed pipe is located, divers station the exposure/suspension lengths, inspect for stress corrosion, coating failures, river weight condition/ spacing, cracks, pitting, max allowable suspended lengths, debris, foreign object damage and abrasion.

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Pipeline Repair

Logan divers have the experience, equipment, and knowledge to locate, inspect, assess, recommend, and repair your subaqueous pipeline.

Coating failure can be renewed underwater in a variety of methods depending on the existing condition and type. Commercial diver inspection of exposed pipe includes coating inspection for defects and holidays.

River weight defects can be corrected in place.

Debris issues on exposed or suspended spans are highly detrimental and can be removed immediately utilizing underwater lift bags and hydraulic chainsaws

Suspended or washed out spans can be stabilized via the cement bag method where the pipeline is supported and stabilized using 80 lb 3:1 sand/cement erosion control bags.

Pipeline leak repairs can be accomplished by installation of industry standard clamps or by the installation of custom made clamps that address the specific requirements of the failure. Pipelines can be repaired by clamping the failure or sectioning with spool piece and double clamp installation. Repair by underwater welding of pipeline clamp is another option where required.

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Pipeline Corrosion Control

Cathodic protection survey and inspection are provided by Logan Diving & Salvage’s diving personnel. Underwater potential readings acquired by the diver at set intervals are collected and presented in report form for analysis.

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Pipeline Location

Pipeline location for anticipated construction activities near the crossing/right of way is a common occurrence. Logan Diving & Salvage's commercial divers locate pipelines electronically and physically. Pipelines are buoyed to mark their route for barge spudding operations or dredges. Pipelines that are not exposed are located by hand jetting or probing and buoyed with depth of cover established and documented.

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