Marine Construction
Areas of Focus
Harbor Services
When Brennan manages your harbor operations, you gain real-time visibility into barge locations, arrivals, and departures by maximizing efficiency and minimizing downtime. All our vessels are U.S. Coast Guard Subchapter M–compliant, and we’re proud members of the American Waterway Operators (AWO) Responsible Carrier Program (RCP). With Brennan, you can count on safe, professional, and transparent harbor management every step of the way, for every type of operation.
- 24-hour dispatch
- AWO RCP-compliant vessels
- Barge cleaning
- Real-time tracking
- Short-haul towing
- Shipyard services
- Switching and fleeting services
Maritime Security Barriers
Brennan is the exclusive supplier of Harbor Offshore Barriers™, the global standard for maritime security, and a trusted provider for the U.S. Navy’s floating protection program. Our fixed and floating barrier systems safeguard critical infrastructure against fast inshore attack crafts, multiple-boat assaults, explosive devices, and underwater intrusions—offering proven defense before, during, and after impact.
- Airports
- Bridges
- Chemical plants
- Dams and hydropower plants
- Desalination plants
- Shipyards
- Liquefied natural gas (LNG), oil and transport facilities
- Military facilities and installations
- Nuclear power plants
Underwater Inspections and Survey
When a project’s greatest risks lie beneath the surface, Brennan delivers clarity. Our licensed hydrographers use advanced survey technologies to create precise, detailed models of underwater environments helping clients identify challenges, reduce risk, and plan with confidence. Our underwater investigation capabilities surpass other contractors, and include:
- Dive inspections
- Light detection and ranging (LiDAR)
- Multi- beam and single-beam bathymetric surveys
- Photogrammetry
- Remotely operated vehicles (ROVs)
- Side-scan sonar
- Underwater acoustic imaging
- Voyis Visual Simultaneous Localization and Mapping (VSLAM)
Dive Inspections
With 100+ ADCI-certified divers on staff, we conduct a thorough assessment of your structure, identify areas of interest, and produce a detailed report that can be used for further analysis.
- Concrete assessment
- Core sampling
- Historical artifact assessment
- Intakes and outfalls
- Micro-dredging and clearing
- Radiological contaminated diving
Public Waterfronts and Marinas
At Brennan, we specialize in transforming public waterfronts into vibrant, inviting destinations. From serene lakefront parks to bustling marinas, our team collaborates seamlessly with public agencies, private organizations, engineers, and waterfront property owners to bring each vision to life. Blending craftsmanship and innovation, we restore and construct durable, safe, and visually stunning waterfronts that enhance both beauty and functionality, creating lasting spaces for communities to enjoy.
- Breakwaters
- Boat landings
- Cruise ship terminals
- Fishing piers and wharfs
- Industrial waterfronts
- Marinas
- Pedestrian docks
- Walkways and promenades
- Public parks and waterfronts
- Quays
- Jetties
Fossil Fuels
Brennan provides a full range of services to maintain and enhance the performance of critical industrial infrastructure. From the precise cleaning of cooling towers and circulating water systems to pipeline inspection and repair, our experienced team delivers safe, efficient solutions tailored to the demanding needs of facilities that rely on fossil fuels.
Areas of Expertise
- Barge terminals
- Port facilities
- Cooling systems
- Traveling water screens
- Pipeline installation, repair, and replacement
- Coal ash ponds
- Manufactured gas plant (MGP) remediation
- Environmental remediation
Hydroelectric Dams
Maintaining reliable, efficient hydroelectric operations requires expertise both above and below the waterline and Brennan delivers exactly that. Our team specializes in hydroelectric dam construction, repair, and rehabilitation, from replacing bulkheads and repairing submerged trash racks to building entirely new structures. Backed by experienced welders, ADCI-certified commercial divers, and specialized marine equipment, we provide safe, high-quality solutions that keep your hydroelectric facilities generating clean, dependable power for years to come.
- Anchoring
- Cofferdams
- Fish passage and protection
- Gates, actuator, and mechanicals
- Intakes and trash racks
- Major rehabilitation
- Penstocks
- Powerhouse structures
- Spillways
- Tailraces
Nuclear Generation Facilities
In the highly specialized world of nuclear power, safety and precision are non-negotiable. Brennan provides a comprehensive range of underwater services tailored to the unique demands of nuclear generation facilities. Our ADCI-certified divers are trained to perform VT-1 and VT-3 visual examinations, execute complex repairs on reactor components, and work safely in challenging underwater environments. We support the inspection, maintenance, and repair of condensate storage tanks, fuel transfer systems, valves, and other critical infrastructure along with expert underwater welding and coating applications. Backed by strict compliance standards and a culture of safety, Brennan ensures your nuclear facility operates at peak performance, maintaining the reliability and longevity of this essential energy source.
- Coating application
- Cooling pond dredging
- Condensate storage tanks
- Fish protection
- Fuel transfer systems
- Intakes and outfalls
- Reactor components
- Traveling water screens
- Valves and seals
- Visual examinations (VT-1 and VT-3)
- 10 Code of Federal Regulations (CFR) 50 Nuclear Quality Assurance (NQA1 Program)
- Maritime security barriers
Transmission & Distribution
Brennan is the trusted marine contractor for water-based transmission and distribution projects across the nation. We specialize in deep foundations, shoring systems, and sheet-pile structures in challenging environments such as rivers, marshes, and wetlands. Our amphibious equipment gives us a unique edge allowing us to access remote sites and complete complex work with minimal environmental impact. Collaboration is at the heart of every project. We work closely with clients, engineers, and contractors to solve complex, water-based grid-hardening challenges. Our experienced crews are skilled in low-clearance operations, efficiently completing work beneath railroad bridges and power lines using a versatile array of specialized tools and equipment.
- Geotechnical support
- Marsh and wetland site access
- River crossings
- Scour remediation
- Transmission tower foundations
- Tower removal and replacement
- Utility pole shoring
Submarine Cabling
Brennan is an industry leader in submarine cable installation and nearshore marine construction. We provide comprehensive cable installation, inspection, repair, and maintenance services for the offshore wind industry as well as inland and coastal cable crossings throughout the United States. With extensive experience and specialized marine capabilities, Brennan is the trusted partner for reliable, efficient, and precise submarine cabling solutions.
- Cable repair and maintenance
- Post-lay cable protection
- Route preparation
- Shore-end civil and site work
- Submarine cable inspection
- Submarine cable installation and removal/replacement
- International Marine Contractors Association (IMCA)-compliant dive services
Environmental Restoration
At Brennan, we are committed to restoring and protecting our natural waterways. We work closely with clients and their engineers to design and execute effective solutions for complex restoration and remediation projects. Our turnkey services include environmental dredging, dewatering, and water treatment, each tailored to the specific needs of the site. With precision, innovation, and environmental stewardship at the core of every project, Brennan delivers lasting results for cleaner, healthier ecosystems.
- Capping
- Coal ash ponds
- Cooling ponds
- Habitat restoration
- Manufactured gas plants (MGP)
- Marshes and wetlands
- Water treatment
Ship Terminals and Piers
Brennan is a trusted leader in marine construction, specializing in the development and rehabilitation of ship terminals, piers, wharfs, and other waterfront infrastructure. With a deep understanding of the complexities of coastal and marine environments, we deliver high-quality, durable solutions that support the shipping industry’s essential logistics and transportation networks. From new terminal installations to pier restorations, our experienced crews build strong, resilient structures designed to perform in even the most demanding conditions.
- Berthing piers
- Closed cell heavy-lift docks
- King-pile wall systems
- Mooring, berthing, and breasting dolphins
- Open Cell® structures
- Pipe-pile structures
- Sea walls
- Sheet-pile walls
Areas of Expertise
- Armoring and fendering
- Concrete placement
- Grouting
- Pile driving
- Pile jacketing
- Precast concrete placement
- Scour and erosion remediation
Coastal Resiliency
With more than 40 years of environmental remediation experience, Brennan understands what it takes to build enduring coastal resiliency. Our teams design and deliver tailored, sustainable solutions, both natural and structural, to restore and protect vulnerable shorelines. Having successfully restored hundreds of acres of freshwater and saltwater habitats, we help clients fortify communities and ecosystems against extreme weather and environmental stressors. Every project reflects our commitment to long-term resilience, environmental health, and coastal sustainability.
- Barrier islands
- Beach renourishment
- Breakwater tubes
- Canals
- Coastal wetlands
- Erosion protection
- Estuaries
- Surge barriers
Inland Waterway Infrastructure
Drawing on over a century of experience, Brennan provides comprehensive marine construction services for the nation’s inland waterways. Our crews specialize in concrete placement, pile and sheet pile installation, and other structural improvements that ensure durability, safety, and long-term performance across all types of water-based infrastructure.
- Barge terminals
- Closed cell heavy-lift docks
- Intakes and outfalls
- King pile wall systems
- Marinas
- Open cell structures
- Pipe pile structures
- Public waterfronts
- Sheet pile walls
Barge Terminals
With a deep understanding of the unique challenges of terminal construction, we efficiently build and repair heavy-lift docks, loading docks, and dry and liquid bulk terminals from both land and water. Our experienced crews ensure safe, high-quality, and timely delivery on every project.
The Great Lakes
Brennan specializes in constructing and maintaining ship terminals, repairing and building docks, and performing large-scale rock work across the Great Lakes region. We also provide essential support for mining and energy operations, ensuring dependable marine infrastructure where it matters most. With a proven record of success on projects for the U.S. Army Corps of Engineers, we uphold the highest standards of quality and safety. Our experienced team is committed to delivering exceptional results, helping your operations thrive in the dynamic Great Lakes environment.
Dredging
Brennan has been a leader in dredging services for over 70 years, providing top-tier mechanical and hydraulic dredging solutions for waterways across the nation. We specialize in dredging around piers, shipping channels, and inland infrastructure delivering efficient results with minimal disruption to your operations.
- Hydraulic dredging
- Mechanical dredging
- Diver-assisted micro-dredging
- Barge and pipeline transport
- Dewatering
- Water quality management
- Marsh and wetland restoration
