Methanol fuel tanks
According to the IMO regulations for low flashpoint fuels methanol fuel tanks can be one of three types:
- Integral fuel tank or,
- Independent fuel tank or,
- Portable fuel tank.
Tanks containing fuel should not be located within accommodation spaces or machinery spaces of category A.
Integral fuel tank
The integral fuel tank is basically the same kind of tank as normally used for marine gas oil, however the methanol fuel tank should be surrounded by cofferdams. Cofferdams are not required below the water line, because it is it is non-toxic to aquatic life and biodegradable.
Independent tanks
Independent tanks are self-supporting, do not form part of the ship´s structure and are not essential to the hull strength. Independent tanks can either be positioned above deck or below deck. When positioned below deck, the space in which the tank is placed is called the fuel hold space.
Independent tanks should:
- be secured to the ship's structure;
- have mechanical protection depending on location and cargo operations;
- if located on an open deck, have drip tray arrangements for leak containment and water spray systems for emergency cooling; and
- if located in a fuel storage hold space, the space should meet the provisions for fire-safety and ventilation.
Portable tanks
A portable tank is similar to an independent tank with the exception that it can be easily connected and disconnected from the ship´s systems and that it can easily be installed on- and removed from the ship.
Portable tanks should:
- be secured to the deck while connected to the ship systems
- have mechanical protection depending on location and cargo operations;
- if located on an open deck, have drip tray arrangements for leak containment and water spray systems for emergency cooling; and
- if located in a fuel storage hold space, the space should meet the provisions or fire-safety and ventilation.
