The large range of activities carried out on or near the sea during marine operations will result in high-risk activities that demand very intensive approaches to monitor and control during the hazard identification, or HAZID, study or Risk Assessment (RA). Below are some examples of the kinds of vessels that are utilized in offshore operations.
Type of vessel operations in offshore include:
Supply Vessel: These vessels transport goods, equipment, and personnel to offshore platforms, rigs, and installation.
Diving Support Vessels (DSVs): Used to support diving operations for inspection, repair, and maintenance of offshore structures.
ROV Support Vessel (RSV): An ROV support vessel is a vessel with specialized equipment and space to store, deploy, and support ROVs for their subsea intervention.
Transportation Barges and Tug Boats: Subsea structures are normally transported from onshore to the offshore installation site by transportation barge. Generally, the transportation barges are towed by tug boats from one location to another.
Heavy Lift Vessels (HLV): A heavy lift vessel (HLV) is a vessel with a specific crane that has a large lifting capacity. These vessels are equipped with heavy lifting equipment such as cranes, derricks, or jib arms capable of hoisting and moving extremely large and heavy objects.
Pipe-Laying Barges (PLB): Pipe-laying vessels can be categorized according to their pipe-laying methods based on site characteristics such as water depth, and weather. The typical three types of PLB are S-Jay, J-Jay, and reel-lay type.
Umbilical-Laying Vessel: Umbilicals can be installed by a reel-lay vessel or carousel-lay vessel where the umbilical are cables, or hoses that contain multiple components such as power cables, hydraulic lines, and control lines.
General Hazards of Marine Operation
The following are the general hazards of maritime operations that are identified during hazard identification, hazard identification studies, or risk assessments (RAs).
- Collisions: Barges can collide with other vessels, structures, or natural features, leading to damage to property, injury, or loss of life. Collisions may occur due to factors such as poor visibility, navigation errors, or equipment failures.
- Grounding: Barges can run aground on shoals, sandbars, or other underwater obstacles, especially in shallow or poorly charted waters. Grounding can cause damage to the barge, cargo, and the environment, as well as disrupt navigation in the area.
- Capsizing or Sinking: A barge can capsize or sink due to factors such as adverse weather, improper loading, or structural damage.
- Cargo Spills: Transportation barges often carry bulk cargo such as oil, chemicals, or other hazardous materials. Spills of these substances can occur due to accidents, leaks, or improper handling, resulting in environmental pollution and harm to aquatic life.
- Fire and Explosion: Cargo carried on transportation barges, such as fuel, chemical, or flammable materials, can pose a risk of fire or explosion, especially in the event of a collision, grounding, or equipment failure.
- Navigation hazards: Barges may encounter navigation hazards such as bridges, locks, dams, and other vessels, which require careful maneuvering and coordination to avoid collisions or other incidents.
Safeguards protection of Collision hazards
The following are the general safeguards protection against collision hazards that are identified during hazard identification (HAZID) or risk assessments (RAs).
Collision hazards: Collision hazards are common hazards in Maritime Operations, Vessel owners and masters should ensure that any operations that involve approaching, working alongside, and departing from any offshore facility are at all times.
- Navigation Rules and Regulations: Commonly called 72 COLREGS (Convention On the International Regulations for Preventing Collisions at Sea) which were developed by the Inter-Governmental Maritime Consultative Organization (IMCO) which was renamed to Internation Maritime Organization (IMO).
- Safety Zone: The Safety Zone or Exclusion Zone is the area around offshore platforms where unauthorized vessels are prohibited from entering to prevent collision.
- Dedicated approaching location: The approaching location course will take the vessel to a position where it can be set up for intended operations. This course is set at a tangent to the safety zone. The direct approach is forbidden.
- Proper selection of the station-keeping method. The operation vessel shall assess the station-keeping location which shall be supported together with prevailing and forecast conditions.
- Proper setting up before moving alongside: Vessels should set up in the vicinity of the face to be worked on the appropriate heading. When setting up to work in a drift-on situation the vessel should be directly up-weather and/ or up-tide of the facility.
- Use of Dynamic Positioning (DP): DP is a control system used to automatically maintain the position and heading of a vessel without the need for traditional anchoring. DP system utilize a combination of propulsion thrusters, sensors, and control algorithms to continuously monitor and adjust the vessel’s position and heading relative to a set reference, typically specified by GPS coordinated or a fixed location.
- Electronic Navigation Aids: All vessels shall be equipped with navigation aids (NAV. aids) to detect other vessels and obstacles.
- Gyro Compass: Gyro Compass is used to find the correct north position, unlike a magnetic compass, the gyrocompass is not interfered with by an external magnetic field.
- Radar: Marine vessels rely on a S-band and X-band radar system for navigation the object and display information on the screen such as distance from ground, obstacles, etc.
- Global Positioning System (GPS):
- Electronic Chart Display and Information System (ECDIS): ECDIS is developed from the Electronic Navigational Chart (ENC) which can integrate with radar, GPS, AIS, and Echo sounder:
- Automatic Radar Plotting Aid (ARPA): ARPA displays the location of the ship and other vessels nearby. The radar displays the location of nearby ships and selects a course for the ship.
- Automatic Identification System (AIS): AIS is used for vessel tracking. It broadcasts a vessel’s identity, position, course, speed, and other relevant information accurately. AIS used VHF radio channels as transmitters and receivers between vessel.
- Prevailing condition monitoring
- Wave height is not more than 1.5 meters
- Wind speed at 10 m above sea level is within 20 knots.
- Lookouts and Watchkeeping: Vessels maintain a proper lookout at all times to visually observe the surrounding.
PROcess Safety TASK 