LNG is transported in purpose built, state-of-the-art vessels, sailing to and from designated ports of call under the most stringent standards. Worldwide, there are about 359 of these LNG carriers, with about 50 more on order or under construction. LNG shipping has an excellent safety record: no major accidents have occurred in more than 30 years, and no release of LNG has occurred during a total of about 40 million miles traveled on 45,000 voyages. In addition, LNG carriers contribute few greenhouse gasses compared to conventional vessels due to their natural gas propulsion system.
LNG carriers are of double hulled construction with cargo (LNG) stored in four to five containment structures, each of which is typically constructed of four layers to protect against breaches or leaks and to keep the LNG cold. A direct breach of the outer layer of an LNG tanker would not cause a product release, or provide an imminent threat.
LNG carriers are among the strongest, safest, and most technologically advanced vessels in the world. They are equipped with sophisticated cargo monitoring and control systems including:
- Bow thrusters for increased maneuverability at slow speed while entering or departing from restricted waters such as ports and terminals
- They are outfitted with sophisticated gas and fire detection and suppression systems. Detection equipment is so sensitive that leakage through a pinhead size fracture would set off an alarm, and trigger a response.
- LNG containment structures are insulated to limit the amount of LNG that boils off or evaporates; sometimes this boil off gas is used as fuel to power the ship.