Neptune LNG Buoy Servicing

Semper has been the lead service provider of the Neptune Deepwater Liquid Natural Gas Pipeline located in 270 feet of water 20 miles East of Boston in Massachusetts Bay.

Over the past several years, Semper has provided dozens of visual and acoustic inspections through both ROV and AUV robotics as well as our divers. Repairs to the pipeline include pressure washing by both ROV and divers, sacrificial anode replacement, concrete articulated mat replacement, and more.


Highline Bridge

Semper Diving & Marine was contracted to install driven pile foundations for a Replacement Railroad Bridge owned by the Massachusetts Bay Transportation Authority located in Somerville, MA. The need for the bridge to be placed on a Driven Pile Foundation was due to the underlying soft compressive soils at the bridge location. The Structure is now fully supported down to the Bedrock on an H-Pile Foundation.

Outcome: Due to the existing bridge to be replaced and constrained on-site staging area, it was a challenging project. The crew was able to establish a safe and efficient working environment while conducting operations directly between live Railroad tracks. Strong and effective communication between RR Workers and the Pile Driving Crew allowed Semper to complete the work within the foul zone of the tracks with 0 incidents.


Hixbridge Road Pile Rehabilitation

The Hixbridge Road Bridge pile repair project in Westport, MA included grout removal and cleaning on the bridge’s concrete piles, in addition to grout pouring and steel pile jacket installation.


Kendall Culvert

Need: Improvement of the Utility Infrastructure and construction of a new Duct Bank system for this project required deep excavations through busy city streets. Semper was contracted on this project for to design, furnish, and install a temporary Support of Excavation system to allow the utility contractor to complete their scope of work. The purpose of temporary support of excavation system is to minimize the excavation area, ensure that system is capable of limiting ground movements to avoid damage to neighboring utilities or structures as well as maintain stability and operation of the surrounding city streets and sidewalks adjacent to the excavations.

Outcome: Due to the scale and location of the project, Semper constructed several SOE systems in various locations of the project, every system installed was constructed around both known as well as unknown utilities found during the excavation that intersected the trench at all different angles and elevations which were also temporarily supported throughout the scope of the utility work. With excavations ranging in cut depth from 14 to 25 feet, Semper utilized various layouts combinations of Soldier Pile and Lagging Walls to accommodate for the depth of the cut as well as accommodate the existing utilities below grade. The soldier piles are driven prior to the excavation beginning, and the wood lagging is added as the excavation descends. Wide flange beams distribute the loads of the horizontal struts to the walls of the soldier pile. The struts’ capacities are determined by buckling considerations because they are compression members. Lateral supports reduce the effective lengths of the struts while increasing their capacities.


Enbridge / Connecticut Pipeline

Need: For this project Semper Diving and Marine’s team of Divers assisted our client in performing pipeline remediation to a previously installed Natural Gas Line. Semper was contracted to inspect the exposed pipeline and all components for defects and remediate the exposed portion of pipeline to prevent future damage & scour.

Outcome: Semper mobilized portable sectional barges that were constructed on site as well as a constructed a temporary loading area for marine access where the barges were launched and constructed as well as loaded from. For the submerged pipeline inspection our trained divers used Non-Destructive and Visual Inspection methods to assess the condition of the Pipeline and it’s coating. After completing the inspection and assessment portion of the project, our divers installed a multi-layered rock shield over portions of the pipeline where exposed or scoured. Our team of divers and workers were able to create an efficient and effective working arrangement with limited marine access, nearby proximity to Dams, as well as within a protected Wildlife Observation Area. The project was completed within the timeframe required by the owner and with 0 incidents.


Emily Anne Ship Salvage

The tugboat Emily Ann sank outside Boston Harbor and keeled over before resting on the seafloor upside down (all hands were recovered safely).

After searching for the wreck with both our AUV and ROV, Semper successfully recovered the sunken tug.


BRA Water Shuttle Relocation

Semper worked with the Boston Redevelopment Authority to relocate a water taxi pier within the Charlestown Navy Yard in Charlestown, MA.


Longfellow Bridge Grout Repair

Semper’s divers and pile drivers worked upon one of Boston’s largest bridges spanning the Charles River.

Work included pressure washing and repairing the grout and granite along the structure of the bridge both above and below the waterline.


Boston Water and Sewer Commission Dive Services

Semper Diving and Marine won Boston Water and Sewer Commission’s Diving contract to be the BWSC’s sole provider of dive services. Since the inception of the contract, Semper has provided inspection services to a variety of locations in the Greater Boston area and Boston Harbor as well.