Is bigger better for gas carriers?

Is bigger better for gas carriers?

Oct. 4 2022 - 4 min

2022 has been marked by headlines about the conflict in Ukraine. Now, its disruption of the European gas supply has come to dominate frontpages too. With pipelines progressively shut-down, sea transport has had to pick up the slack and deliver liquefied gas across the continent.

Liquefied gas flows from the US may accelerate a trend in gas carriers: toward much larger vessels, which is no doubt welcome news to those fretting over fuel shortages. The US notably has new very large LNG carriers on order – and a couple that recently entered service – with plans to accelerate the development of liquefaction terminals to meet demand.

Looking deeper into gas carriers

However, attributing this new generation of very large gas carriers to a single socio-political event doesn’t paint a full picture. Firstly, the conflict has impacted the LNG sector most heavily, while LPG remains practically unscathed. Secondly, while it is mainly European supply that is disrupted, the trend in gas carrier size is global. The fact is that larger vessels are proving to be one of the necessary features of the future maritime world.

Carrying as much as 200,000m3, these ocean giants are able to transport larger cargoes over longer distances than standard 174,000m3 vessels. This will enable greater flexibility in transcontinental operations, crucial in a fluctuating energy market. Additionally, these high-capacity vessels are designed with four cargo tanks which make them simpler to handle and reduce associated CAPEX and OPEX compared to similar existing QFlex carriers.

Future gas carriers in numbers

While debate continues on which zero-carbon fuels will dominate in the future, the gas carrier market has already got some capacity to transport one of them. There are currently around 450 ammonia-capable ships in service around the world, whereas liquid hydrogen boasts only one.

Tanks get in on the trend

The Bureau Veritas-classed fleet counts nine 200,000m3 LNG carriers. These massive ships are each equipped with four large tanks. At such huge volumes, safety and stability are naturally vital concerns. Bureau Veritas experts help to minimize risks by performing sophisticated computer fluid dynamic analysis to reduce sloshing risks.

But size is not the only design innovation when it comes to tanks. The ability to carry one or several liquefied gases in proven or developing containment systems is also under investigation. Type A and C tanks are to be used for ammonia in alternance with other cargos, mainly LPG. Membrane tanks for larger ships will also need further development – possibly allowing ammonia and hydrogen cargoes. Additionally, studies into the use of ammonia as fuel – and potentially hydrogen as fuel – possibly mixed with other fuels to be used as both cargo and fuel are in development.

Pioneering safety for large gas carriers

Bureau Veritas has a long history of supporting gas carriers’ progress, including classing some of the first and the largest LNG carriers. From structure and equipment to cargo flammability, we have turned our years of experience into comprehensive safety guidelines for all types of gas carriers. Now, as ships increase in size and undertake longer journeys, we will continue to help ensure structural integrity through fatigue and sloshing analysis.

In the future, should ammonia and hydrogen carriers grow in number and size, we will be ready to further support these developments. Already, we have published Rules for ammonia-fueled ships, and have issued AiPs for large liquefied gas carriers combining ammonia as cargo and as fuel to major shipyards.

As on display at Gastech 2022,  the sector is showing no signs of slowing down in terms of innovations. Building on our history and industry proximity, we are excited to support owners and yards as they take ever-larger steps forward.

Photo credit: Dynagas