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Commercial Diving

Underwater Services

Stearns Engineering has more than two decades of experience providing the following underwater services:

  • underwater structural inspections of bridges, marine structures, and dams
  • quality control inspections of underwater construction and repairs
  • contaminated water, penetration, and confined space diving
  • support of topside bridge work  - OSHA life-saving skiff

A Stearns Engineering Bridge Inspector documents exposed reinforcing steel at a void in a concrete bridge pier.

Underwater Inspection

For nearly a quarter of a century, Stearns Engineering has performed underwater structural inspections of bridges, marine facilities, and hydraulic structures. Our company has completed the underwater inspections of more than twenty-five hundred structures, working for federal, state, and local governments and successfully teaming with the nation’s leading engineering firms.

Our staff includes Registered Professional Structural Engineers to supervise and perform underwater inspections.

Stearns Engineering specializes in underwater structural inspections, unlike many marine contractors and commercial diving companies  who view underwater inspections as one of a range of diving services.  We perform visual and tactile inspections and testing of all types of marine structures. Our detailed inspection reports include field observations, structural condition assessments, and recommendations for repairs.

All underwater bridge inspections performed by Stearns Engineering conform to current AASHTO and NBIS standards. We are experienced in preparing PONTIS ratings and are familiar with the bridge management and structure inventory and assessment programs of many governmental agencies.  Reports are prepared with scale AutoCAD drawings showing the locations of anomalies and defects with keyed notes describing pertinent information.  Collected data may include:

  • underwater video and digital photographs
  • non-destructive/ultrasonic testing results
  • concrete and timber coring results
  • hydrographic/fathometric surveys
A Stearns Engineering three-man inspection crew performs a routine equipment and communications check prior to an inspection dive.

All underwater bridge inspections performed by Stearns Engineering conform to OSHA's 29 CFR, Part 1910, Subpart T - Commercial Diving Operations, including the requirement of a three-man (minimum) dive team. Our diving procedures also follow the more stringent requirements of the Consensus Standards for Commercial Diving Operations of the Association of Diving Contractors (ADC).  Stearns Engineering is a General Member of the ADC.  Our underwater inspectors are certified commercial divers trained to ANSI/ACDE standards and are experienced in inspecting submerged structures in adverse conditions, including limited visibility and strong currents.

A Stearns Engineering Bridge Inspector begins the diving inspection of concrete bridge piles.

Contaminated Water, Penetration, and Confined Space Diving

A Stearns Engineering inspection diver completes an underwater video inspection of a sluice gate assembly in a subterranean basin.

In addition to inspecting the nation’s transportation infrastructure, Stearns Engineering provides underwater inspections in industrial settings in support of water and other utilities.

A Stearns Engineering inspection diver surfacing after inspections and repairs in a sequencing batch reactor at a wastewater treatment plant.

We have the equipment and experience to perform underwater inspections safely and efficiently in contaminated water and confined spaces.  Whether inspecting aeration assemblies in an online wastewater treatment plant, or examining the hydraulic structures in a buried condenser pit, our divers work effectively in difficult and hostile underwater environments.

A Stearns Engineering inspection diver returns after inspecting and repairing screw conveyors in a sedimentation basin in an online water filtration plant.

OSHA Safety and Rescue

Stearns Engineering can supply the equipment and personnel required to fulfill the requirements of OSHA regulation 29 CFR §1926.106. This regulations states “at least one lifesaving skiff shall be immediately available at locations where employees are working over or adjacent to water."

In support of topside bridge inspection or repair work, we can provide a vessel, adequately sized for the conditions at the site and manned by a U.S. Coast Guard licensed captain and a rescue swimmer, both of whom are trained and certified in CPR and other life-saving techniques.

Representative Projects & Clients

Underwater inspection of 945 bridges statewide for the Louisiana Department of Transportation and Development

Inspection of underwater repairs to three bridges (including the Chesapeake Bay Bridge)for the Maryland Transportation Authority

Initial inspection, design, and inspections of repairs to the intake structures at Brighton Dam for the Washington Suburban Sanitary Commission

Underwater inspections of approximately 350 bridges statewide for the Connecticut Department of Transportation

Underwater inspection of 25 bridges in the eastern United States and 27 bridges located in National Parks for the Federal Highway Administration

Underwater inspection of bridges in Districts 3, 4, 5, 6, and 7 and emergency underwater inspections of bridges statewide for the Maryland State Highway Administration

Underwater inspection of all bridges and port facilities marine structures owned by the Maryland Transportation Authority

Underwater inspection of 478 bridges located in regions 2, 3, and 4 for the Tennessee Department of Transportation

Underwater inspection of 19 bridges for the Montana Department of Highways

Underwater inspection of bridges statewide for the New Hampshire Department of Transportation

Underwater inspection of bridges statewide for the Vermont Agency of Transportation

In addition to the agencies listed above, Stearns Engineering has provided underwater inspection services to the following clients:

US Army Corps of Engineers
Pennsylvania Department of Transportation
Ohio Department of Transportation
Mississippi Department of Transportation
Maryland Port Administration
Delaware River Port Authority
Baltimore City Department of Transportation
St. Clair County (Michigan) Road Commission
Washington Metropolitan Area Transit Authority (WMATA)
National Aeronautics and Space Administration (NASA)
National Gallery of Art
numerous private firms


Our staff includes Registered Professional Engineer (structural) divers to perform and supervise underwater inspections.  All of our inspection divers have satisfactorily completed Federal Highway Administration approved bridge inspection courses based on the Bridge Inspector’s Training Manual/90 and/or the Bridge Inspector’s Reference Manual and have a minimum of five years experience performing inspections of in-service bridges.  Inspection divers also possess a Level I certification in non-destructive testing and have completed specialized courses in underwater bridge inspection.

Underwater deterioration of a concrete bridge pier documented by a Stearns Engineering Bridge Inspector.

Our underwater inspectors are Certified Commercial Divers trained to American National Standards Institute/Association of Commercial Diving Educators standards.  Each holds a valid certification card from the Association of Diving Contractors as a Surface-Supplied Air Diver or Surface-Supplied Air Diving Supervisor.  According to OSHA’s Interpretation Letter, dated March 29, 2000, “OSHA considers an employer to be in compliance with 29 CFR Part 1910.410 diver training requirements for any diver with a valid ADC [Association of Diving Contractors] Commercial Diver Certification card . . .”

A Stearns Engineering Bridge Inspector probing along pier footing before commencing underwater inspection.

We believe requiring this level of diving training ensures the inspector’s comfort in the underwater environment, guaranteeing his or her ability to focus completely on the tasks of the inspection.  In its 1988 Revisions to the National Bridge Inventory Standards, the Federal Highway Administration observed that “. . . diving competence is the foremost requirement for any underwater inspector.”  Our inspection divers possess both the diving proficiency and engineering expertise to provide optimal assessments of submerged structures and have the commercial diving training and expertise the Bridge Inspector’s Reference Manual calls “paramount to a quality inspection”.  Our personnel meet all applicable qualification requirements of the current NBIS and our staff exhibits unique and highly desirable skill sets which provide superior condition assessments of submerged structures.

It is our firm conviction that the quality of underwater inspections performed by engineers or technicians with only recreational diving certification suffers because of a lack of training in the sophisticated equipment and techniques of commercial and technical diving.  Further, recreational dive training agencies (e.g., PADI, NAUI, SSI, YMCA, etc.) are explicit that their courses do not qualify an individual to work underwater.  The use of personnel with such limited training potentially exposes both the employer and client to increased liability in the event of diving accidents.

Exposed reinforcing steel in a submerged concrete bridge pier documented by a Stearns Engineering Bridge Inspector.

As our diving inspectors have a background in structural design, marine construction, and underwater repair, they are able to determine the seriousness of observed deterioration (by location and/or extent), and to distinguish minor defects from significant structural flaws.  Our firm has extensive experience designing repairs for marine and hydraulic structures and performing quality control inspections of repairs to bridge substructures.  Our familiarity with current industry construction and repair methods and techniques allows us to identify and recommend appropriate and cost-effective repairs.

Our inspection teams have recent experience on bridge structures of all types, of a range of sizes, and in an array of environments.  Recent projects have included contracts to inspect large numbers of relatively small bridges in shallow water, multi-span bridges (one more than seven miles long), and bridges with piers in water with strong currents and depths exceeding one hundred feet.

The right tool for the job.