If a ship is seriously damaged underwater in the area of a large fuel oil side bunker tank, it will cause the following:
Bilging or Flooding of the Compartment:
- Water will enter the damaged bunker tank, reaching the draught level.
- The rate of flooding depends on the size of the breach and the water pressure at the depth of the damage.
Oil Leakage into the Sea:
- If the tank contains fuel oil, oil will begin to leak out, causing pollution.
- The extent of leakage depends on the tank’s contents (empty, half-full, or full) and the location of the damage.
List and Trim of the Vessel:
- The ingress of water and loss of oil will create an imbalance, causing the vessel to list or trim.
If corrective actions are not taken, uncontrolled flooding and loss of stability could lead to capsizing or sinking of the vessel.
Features in the Ship to Enhance Safety:
- Small Bunker Tank Sizes reduces the risk of extensive oil spillage and loss of stability.
- Connectivity to transfer pumps allows the transfer of oil from the damaged tank to an empty tank, minimizing oil spillage and counteracting the loss of stability.
- The tank’s size and location are designed to limit the effects of flooding, as per damage stability regulations.
- Properly positioned transverse and longitudinal bulkheads enhance the subdivision factor, limiting water ingress to the damaged tank.
- Ship’s Ballast System allows corrective ballasting to counteract the list or trim caused by the ingress of water.
- Watertight Doors and Hatches prevent water from spreading to adjacent compartments.
Recommended Immediate Actions by Crew:
For Empty Tanks:
- Quickly seal off the damaged tank by shutting all valves and isolating it from the transfer system to prevent water ingress into other parts of the vessel.
For Half-Empty or Full Tanks:
- Initiate oil transfer to another empty tank to reduce oil leakage and stabilize the ship.
- Monitor the water ingress and ensure the tank is filled to the draught level with seawater if necessary, using ballast to correct the list.