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Marine Construction Services

Founded along the banks of the Mississippi River, we have been working in and along the inland waterways since 1919. Our abilities include above and below-water construction, repair, and inspection services on a wide variety of structures. With a large fleet of specialty marine equipment we can operate in bodies of water that range from small ponds to oceans.

Submarine Cable Installation Services

Submarine Cable Installation & Repair

Our submarine cable installation professionals are proficient in all phases of submarine cable-laying operations. Our project engineering, planning, and execution methods are based on extensive experience, best management practices, and proven techniques. In addition, Brennan invests heavily in modern, state-of-the-art technology and equipment that surpass industry standards for safety, quality, and efficiency.

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Marine Construction, dock construction, dry bulk terminals, barge terminals, liquid bulk terminals, Mississippi River Construction, barge transportation, dock construction, La Crosse WI

Dock Structures & Barge Terminals

Brennan specializes in dock structures ranging from dry and liquid bulk terminals to heavy-lift docks and cellular structures. Our expertise also includes the mooring and fleeting structures needed to maintain an efficient operation. Whether you are building a new dock or extending the life of an existing facility, we can provide a wide variety of services that will optimize the efficiency of your facility.

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marine construction, deep foundations, pile driving, river construction, Mississippi River Construction, inland river construction, cofferdams, tower foundations, seawalls, open cell structure

Deep Foundations

Since Brennan began in the early 1900s we have been building deep foundation structures to support electrical towers, buildings, bridges, and more. This includes cellular structures, Open Cell® structures, reinforced seawalls, and cofferdams. Whether this be from the water, or on land, we can create a customized approach for every project.

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dredging contractor, mechanical dredging, clamshell dredging


Dredging promotes efficiency as much as a well-functioning terminal does. Brennan can provide both mechanical and hydraulic dredging options that will maintain the needed depths for efficient navigation. From mass removal to surgical dredging, we have the ability to right-size our operation for your project needs. This includes projects that may involve rapid dewatering and disposal in offsite locations.

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underwater inspections, dive inspections, divers, diving, commercial diving, hydrographic survey, bathymetric survey, river survey, acoustic imaging, side scan sonar

Underwater Inspections & Survey

We can provide several choices to help you understand the conditions of your structure below the waterline. These options include high quality dive inspections with experienced certified commercial divers, underwater acoustic imaging, and high-resolution multi-beam hydrographic surveys. Each one uses the latest technologies to collect data and create the detailed information that you need to monitor your structures.

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underwater construction, diving, commercial diving, diving contractors, adci divers, certified divers, underwater welding

Underwater Construction

Brennan divers can place concrete, weld, cut, grout, dredge, and accomplish whatever else may be required to keep your structure in good condition. Using divers will eliminate the added cost of an expensive cofferdam structure, and can often truncate the project schedule. Our divers specialize in zero-visibility conditions and use state-of-the-art equipment to carry out quality repairs safely.

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Maritime Security Barrier Systems

Our trademark maritime security systems, Harbor Offshore Barriers™, are designed and fabricated to withstand harsh marine environments. Made using high-density, high-quality materials, including HDPE, to maximize UV resistance, our barriers are built to outlast the effects of maritime conditions.

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marine construction, bridge construction, construction, heavy infrastructure, pile driving

Bridge Construction

Brennan's extensive bridge construction experience will insure your new structure is built to the highest quality, on time, and within budget.  Whether it is a new structure, or the repair of an existing one, our ability to provide both above-water and below-water construction services can lead to additional cost-saving options.

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marine construction, marine support, mississippi river construction, illinois river construction, water construction, towing, barge construction

Marine Support

Brennan’s large fleet of marine equipment is suited for all types of marine construction projects. From our barge mounted heavy pick cranes to our fleet of high-quality portable barges, work flats, john boats, amphibious dump trucks, and portable tow boats, we are equipped to address all of your marine support needs.  Our vessels are USCG inspected and are operated by licensed pilots.

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More Information marine construction, bridge construction, brennan, mississippi river construction

Download our Marine Construction Brochure

J.F. Brennan Company specializes in marine construction projects throughout the inland waters of the United States.  Download our brochure here to learn more about our bridge construction services!

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Careers marine construction careers, pile driving, pile buck, sheet piling

Looking for an Exciting Career?

At Brennan, we are always looking for driven, hardworking individuals who have a passion for working around the water.

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