Maritime Innovation In Miniature
Mozah
This is a model of Mozah, built by Samsung Heavy Industries of South Korea and launched in 2007. Mozah is one of the most important ships in the history of fuel transportation by sea.
She is an ‘LNG’ carrier – meaning that she is designed to transport liquified natural gas.
LNG carriers are among the most difficult vessels to build.
Mozah was the first of a new type of LNG carrier known as Q-Max. At 345 metres long and towering 20 stories tall from keel to masthead, Mozah can carry a staggering 266,000 cubic metres of LNG, enough natural gas to meet the energy needs of 70,000 homes for an entire year.
Q-Max liners are the largest LNG carriers in the world. The Q in their name refers to Qatar – and ‘Max’ means that they are the largest vessels able to dock at the LNG terminals in Qatar.
She is named after Moza bint Nasser, wife of Sheikh Hamad bin Khalifa Al Thani who was Emir of Qatar at the time of her launch.
LNG is created by transforming natural gas into a liquid state, by cooling it to -161oC. The process reduces it in volume 600 times. It is clear, odourless and colourless. As a fuel it produces 40% less carbon dioxide (CO2) than coal and 30% less than oil, which makes it is the cleanest of the fossil fuels. It does not emit soot, dust or particulates.
The cut-away in her hull demonstrates how the liquid gas is stored. A thin layer of corrugated stainless-steel acts as a primary barrier or membrane; these ridges absorb the thermal contraction when the tank is cooled down to store the gas.
Then there is a layer of insulation; followed by a secondary membrane barrier, and a further layer of insulation. Effectively the tanks thus act as a thermos, to keep the LNG cool.
Mozah’s tanks have been designed to standards of hull structure in excess of previous LNG carriers and are the largest ship-board LNG tanks ever built.
She marks a step-change in LNG shipping by reducing transportation cost, whilst improving energy efficiency and reducing emissions.
The innovative Q-Max ships carry up to 80 percent more cargo yet require approximately 40 percent less energy per unit of cargo than conventional LNG carriers. This is due to economies of scale and the efficiency of her specialist slow-speed, electronically-controlled diesel engines. She is also designed with the latest hull antifouling protection and improved fire-protection systems.
Other notable innovative features are her twin propellers and rudders which offer significant advantages when decelerating and manoeuvring such a large vessel in the confined spaces of a port.
There are two separate engines. In case of engine failure, the failed engine can be de-coupled allowing the ship to maintain a speed of 14 knots.
Most important of all, however, are her onboard reliquefaction units. During transportation there is always wastage as some of the liquid boils off and turns back into a gas. In a typical 20-day voyage, anywhere from 2–6% of the total volume of the LNG originally loaded may be lost.
LNG is transported at a temperature of -163 degrees, which means that there is always wastage as some of the liquid boils off and turns back into a gas. In a typical 20-day voyage, anywhere from 2–6% of the total volume of the LNG originally loaded may be lost.
To mitigate this, Mozah is built with units that turn that gas back into liquid. This reduces LNG losses, which produces both economic and environmental benefits.
All of these innovations were approved and certified by Lloyds Register. And the end result was a 20-30 percent reduction in transportation cost and 40% lower energy requirements and carbon emissions than conventional LNG carriers.
Mozah is a ship that is pioneering our journey as we move towards a carbon free future.