LNG Tanker Builders

LNG Carrier Classes: Containment Systems, Capacity and Size Ranges

In practice, LNG carriers are grouped by how they carry cargo (containment system) and how much they carry (capacity range). Those two choices shape the ship’s economics, technical risk and the routes it can serve.

Containment systems

Most modern LNG carriers use one of three main containment families for large deep-sea ships, plus a fourth approach for small-scale trades:

• Membrane tanks (GTT Mark III / NO96 families) . Thin stainless or Invar membranes supported by insulation and the ship’s inner hull. This arrangement makes very efficient use of hull volume and has become the dominant solution for large ocean-going LNG carriers.
• Moss spherical tanks (IMO Type B). Self-supporting spheres that protrude above deck - the classic LNG profile. Moss tanks are built for durability and stable performance, although they generally carry less cargo for a given hull size than membrane designs.
• SPB (Self-supporting Prismatic Type B) tanks. Box-shaped, self-supporting tanks, that combine prismatic volume with Type B safety. SPB systems originated in Japan and are used where deck space, tank-shape flexibility or project-specific layouts are important.
• Type C pressure tanks. Cylindrical or spherical pressure vessels used on small-scale LNG and bunkering vessels, not on mainstream long-haul LNG carriers. They allow higher pressure and more flexible operations for coastal and regional trades.

When owners select a containment system, they are balancing three things - higher cargo volume, very strong construction, or more flexible use on specific routes and products.

Capacity and size ranges

Even though there is no formal standard for capacity, shipowners and builders generally refer to a few common size classes:

• Small-scale / coastal LNG carriers. Typically from around 1,000 m³ up to about 30,000-40,000 m³. These ships serve regional distribution, terminal-to-terminal shuttle work and LNG bunkering.
• Mainstream ocean-going LNG carriers. Most long-haul LNG trades today are concentrated around standard 170,000-180,000 m³ membrane designs. This class has become the default choice for many global export and import projects.
• Q-Flex and Q-Max type large carriers. These membrane ships step up to much larger sizes: Q-Flex: around 210,000 m³ and Q-Max: up to about 266,000 m³, among the largest LNG carriers in service.

New mega-carrier concepts slightly above these capacities are now being developed for future export programs, but the basic picture remains: small-scale carriers for regional and bunkering roles, mid-size carriers for most global trades, and a limited number of very large classes tied to specific terminal constraints and long-term projects. When an LNG project team defines a carrier class, it is effectively choosing a containment system plus capacity band that will set the framework for propulsion, boil-off handling, terminal compatibility and lifetime operating costs.

Navigating Global LNG tanker building centers with Records Marine

LNG carriers are not built everywhere. Historically, about two-thirds of LNG carriers have been built by South Korean yards, with most of the remaining fleet coming from Japan and, more recently, China. In current orderbooks and recent delivery statistics, South Korea and China together account for the clear majority of new LNG carrier contracts each year. For owners, having most LNG carrier building companies in a few places provides reassurance on quality, yet it also creates complexity when a fleet order involves several shipbuilding regions and a mix of containment and engine technologies.

Records Marine is designed to make that landscape easier to read when you are shortlisting LNG tanker builders. Instead of starting from a long list of shipyards by name, project teams can think in terms of what really matters for an LNG newbuild and then use those criteria to navigate the directory.

When you compare potential LNG carrier yards, it helps to focus on a few specific points:

• Containment systems they actually deliver - whether the yard is focused on membrane carriers, Moss-type designs, SPB solutions, or small-scale Type C vessels. This shows how well their portfolio matches the carrier class you have in mind.
• Capacity ranges that dominate their references - some builders concentrate on 170-180k m³ membrane carriers, while others are more active in small-scale coastal LNG or specialized large-capacity programs.
• Approach to propulsion and boil-off gas - whether their standard designs use modern two-stroke dual-fuel engines with partial or full reliquefaction, or older concepts. This choice influences fuel flexibility and how comfortably the ship fits within current and future emissions rules.
• Regional and logistical fit with your team - including supervision, travel and supply-chain arrangements between yards, as well as differences in delivery slots and after-delivery support.
• Track record in similar projects - experience with ice-class requirements, and integration with specific terminal designs or export trains, all of which help reduce project risk.

Records Marine brings these dimensions together in one place, so LNG project teams can move from a global list of shipyards to a focused set of builders whose technology profile, capacity range and regional base match the carriers they intend to order. Shortlisted yards can then be saved, compared and contacted directly when it is time to discuss outline specifications, containment choices and delivery windows.