I. Construction, repair, inspection & maintenance

Construction and repairing of jetty's
Sea bed survey
Block placing
Grouting (concreting) of damaged structure
Repair & rehabilitation of under water concrete / hydraulic structures.
Under water cutting & welding
Under water cutting & removal of piles
Laying of under water cable and pipes.
Erection of underwater structures.
Dredging and desilting
Under water visual inspection,
Under water videography,
Under water still photography
Inspection of pipe lines and cable laying.
Non destructive testing of all under water marine structures.
Data processing & preparation of reports

II Dams & thermal power stations

Repair and sealing of sluice gates, emergency gates, stop lock gates etc.
Leakage arresting repairs using under water epoxy treatment
Under water mapping, grouting, sealing of cavities cutting & welding
Cleaning of gate grooves, m. S. Rod & plate.
Under water rock blasting
Under water cutting & welding
Epoxy, cico treatment for reservoir wall

Repair & Rehabilitation

Underwater repairs and minor rehabilitation routinely performed at scheduled maintenance intervals are possible because of forethought and the planning undertaken during the original design of the structure. These repairs have been performed in water, wastewater treatment and other industrial plants, on pilings and sea walls, under docks and wharves, on dam slide gates and trash racks, and on ocean going vessels. These types of repairs are typically done during a planned outage, shutdown or docking and/or when site conditions are near optimal for divers to easily accomplish their tasks.

Emergency repairs, on the other hand, may be required at the most inopportune time, oftentimes when site conditions can be at their worst. Catastrophic failures of certain civil or mechanical structures which cannot be repaired underwater, must be dewatered, or require that site conditions affected by adverse weather or flooding improve sufficiently to enable divers to practically and safely perform the work. Many of these unexpected emergency repair projects could have been avoided with the implementation of a scheduled routine underwater inspection program. The following types of projects categorize general areas of repairs and rehabilitation with which our diving and technical teams have significant experience:

(1) Pipelines & Tunnels
Tethered diver and ROV penetrations of up to deeper depths.
Installation and pressure testing of internal mechanical seals for joint leak repairs
Pipeline and outfall retrofit of diffuser ports, manhole trunks and "hot taps" for branch pipe installation and extensions, repair and/or replacement of damaged pipe sections
Removal of internal sedimentation, debris buildup and other blockages using hand dredging, pipe "pigging" techniques, and/or mucking of larger objects using divers
Installation and repair of submarine cables and RCP, HDPE, welded steel, and ductile iron pipelines in rivers, bays, exposed coastal and open water environments
Structural repair and concrete restoration of lined and unlined tunnels using epoxy injection, underwater forming, concrete line-pumping or tremie placement methods
Installation of reference electrodes or sacrificial anodes with mechanical attachment at external joints or "wet-welding" externally or internally
Anchoring of existing pipelines to sea bed, placement of concrete filled mats for armor protection and ballast, remedy unsupported pipeline spans

(2) Concrete Restoration & Repair
Installation and pumping of large mattresses to seal and cover damaged, broken and leaking concrete canal lining
Structural repairs to concrete gate vaults, pipelines, concrete sheet piling, bulkheads and lined tunnels and basins using two-part epoxy injection techniques and materials
Leak repairs in large basins using urethane injection techniques
Repair of voids, cracks and spalls in concrete resulting from river scour, subsidence, mechanical damage, failed concrete and structural rebar corrosion on dam faces, intake/outlet structures, sea walls and other submarine structures
Wood, steel and concrete piling and other structural repairs using tubular or nylon bag forms for concrete encapsulation under piers, wharves, bridges and dams
Localized quick-setting concrete patch repair and portable self-contained 2-part epoxy injection underwater repair systems


(3) Structural Rehabilitation & Repair Mechanical & Civil Projects
Intake structure rehabilitation including slide gate, track and seal, and manual operator and support guide repair/replacement on dams, canals and storage basins
Repairs, modification to and replacement of trash-rack and debris screen structures
Abandonment of pipelines, manhole structures, temporary and permanent plugging of pipelines and tunnels
Submersible pump maintenance, repair, removal and replacement
Repair and maintenance to mechanical supports on sanitary outfall pipelines, water intake and discharge lines
Submarine valve and hydraulic control system plumbing repairs and replacement
Industrial and sanitary treatment plant maintenance and repair of mechanical structures in process tanks, basins, ponds, vaults and pipelines
Repair and modifications to diffuser ports, aeration systems, and discharge pipelines
Installation and maintenance of dewatering structures and portable dams in small basins, ponds, lakes, reservoirs and rivers
Repair to boat ramps, floating docks and walkways, water access platforms and steps
Ship husbandry, maintenance and repairs to the underbody of ships including anode installation, propeller replacement and shaft seal repairs, hull cleaning and propeller polishing, removal of biofouling prior to dry-docking, cofferdam and plug installation for overboard discharge and intake valve service and replacement
Pile restoration and wood pile concrete encapsulating
Anode installation for cathodic protection

(4) Underwater Welding, Cutting, Salvage & Demolition
Structural repairs to sheet piles barriers and cellular cofferdam structures, bonding strap reinforcement repairs
Ship husbandry, maintenance and repairs including repair of side and bottom shell damage, AWS D3.6 coded "wet-welding" for patch installation, sacrificial anode installation, propeller trimming, installation/removal of rope guards and cable removal from propeller and shaft
Underwater dry habitat weld repairs for pipelines and other structural steel and support platform members; wet-weld repairs to screens and gates, sacrificial anode installations and continuity welds for impressed current protection for pipelines
Steel sheet and support pile oxy-arc cutting and removal, demolition and removal of steel rail track and structural steel debris
Heavy equipment salvage, with engine preservation and "pickling", heavy lift rigging and water transport, and complete mechanical restoration of farm equipment damaged from flooding
Concrete demolition and removal using impact hammers and breakers, core drilling, roto-impact and rock drilling, hydraulic concrete splitters, diamond wire and circular saw cutting, and underwater explosives
Modifications to reinforce fish ladders, basin walls, and RCP submarine outfalls and outlet/intake structures
Demolition and removal of large concrete piers and columns, concrete dams, wharf and dock pilings, sea walls and abandoned pipeline, penstock, tunnel, and manhole concrete plugs

(5) Dredging, Debris Removal & Excavation
Pipeline cleaning and sediment removal using "sewer ball" pigging, directional jetting and suction, and pressure pump backwater/reverse nozzle flushing techniques
Airlifting and water-lift educators for removal of biofouling debris accumulation, excavation of mud, clay and sandy bottoms to expose pipelines, cables, and structures
High pressure water blasting for epoxy coating removal, biofouling and corrosion or scale removal, and structural/substrate preparation of weak or damaged concrete for encasement and sealing repair
Pipeline and cable burial or exposure for protection or exposure to perform repairs
Debris removal for retrofit and repair to bridge piers, footings and foundations
Sediment removal in and around intakes on dams, siphons, pump stations and low level basins, marinas and boat ramps, adjacent to sheet pile cofferdams during shoreline and/or stream bed restoration, and for any marine construction