The NO96 containment system from Gaztransport & Technigaz SA - membrane design anchors modern LNG carriers

Reviewed: ad hoc news Classics & Longseller desk. Edited and checked on 2026-06-28, 09:25. Details in the imprint.

The NO96 containment system from Gaztransport & Technigaz SA sits hidden below deck, a vast grid of insulated boxes and thin steel membranes that never sees the sea breeze but decides whether LNG stays cold and where it belongs. On a loaded carrier, crew hear a muted, steady hum from pumps and compressors while the cargo tanks themselves remain eerily quiet. The steel feels cold through a glove, even with all the insulation between ship structure and minus-162-degree liquefied gas.

How NO96 is built

The NO96 containment system is a membrane cargo tank technology that lines the inside of an LNG carrier hull with prefabricated insulation boxes and thin metal membranes instead of using self-supporting steel tanks. Each tank is made up of a double barrier: two separate metallic membranes separated by layers of insulation in a modular lattice. This design lets shipyards adapt tank size and shape closely to the hull, which means more cargo volume for the same overall ship dimensions.

At the heart of the system, each membrane is typically a thin invar or stainless steel sheet supported by plywood boxes filled with perlite or other insulating material. The boxes are arranged like a giant egg-crate, each one aligned and fastened so the membrane can flex without cracking when the hull moves at sea. An engineer who has walked inside a partially built tank describes stepping carefully across bare insulation boxes, hearing the hollow echo of boots in a space that will later be sealed and invisible for the ship’s entire working life.

Thermal performance in daily operation

The NO96 architecture is designed to limit boil-off gas, the small fraction of LNG that warms and evaporates during transport. In practice, operators aim for a daily boil-off rate on the order of tenths of a percent of tank volume, which can be used as fuel instead of vented. The double-membrane layout and layered insulation slow heat ingress so the cargo stays near its cryogenic temperature while the ship crosses oceans for weeks.

When a vessel loads at an export terminal, cargo officers watch temperature and pressure graphs on screens while valves open with a low hiss. Inside the NO96 tanks, the membrane and insulation absorb mechanical stresses as cold LNG pours in, so the hull can flex in swell without concentrating loads in a few spots. The crew never see the membranes directly in service, but they see the effect in stable readings and quieter alarms during heavy weather.

Why shipyards pick NO96

Shipbuilders choose the NO96 containment system when they want proven performance and compatibility with large-volume LNG carriers and floating storage units. The modular box approach makes it easier to fit tanks into different hull designs while keeping a consistent thermal and mechanical behavior across projects. For a yard, this can mean smoother classification approvals and fewer surprises during sea trials.

GTT engineers such as chief technology officer Philippe Berterottière, who also serves as CEO, often emphasize that NO96 embodies decades of feedback from ship operators and classification societies. He has described the system as a way to balance efficient cargo capacity with safety margins that work in heavy seas and long routes, where even minor design weaknesses would show up quickly in operating data and maintenance logs.

Maintenance and inspection realities

In service, the NO96 containment system requires careful inspection routines, especially when a ship enters dry dock. Technicians walk along internal access ways, using gas detectors and visual checks to look for signs of membrane deformation or insulation settlement. Any anomaly, such as a small condensation patch or unusual frost pattern, can trigger more detailed investigation.

Working inside the tank spaces is demanding. Shipyard workers often describe the air as cool and faintly smelling of plywood and insulation when the tanks are empty and warmed back to ambient. They crawl through tight passages, running gloved fingers along weld lines or supports, listening for the dull tap that means a box is firmly seated instead of loose. The NO96 layout gives them repeatable points to check because the lattice follows a regular pattern.

Role in the LNG value chain

The NO96 containment system sits at a crucial link in the LNG value chain. Without reliable cargo tanks, huge liquefaction plants and import terminals would face more risk in each shipment, undermining the economics of long-haul LNG trade. Membrane systems help keep transport predictable so contracts based on delivery windows and boil-off rates can be honored.

For energy companies, choosing ships with NO96 tanks is part of a broader strategy to manage emissions and fuel costs. If boil-off gas can be precisely forecast and used in propulsion systems, operators cut reliance on separate fuel oil and improve voyage economics. That precision depends on how the membranes and insulation perform across a range of ambient temperatures and sea states.

Competition and alternatives

NO96 does not operate in a vacuum. Alternative containment designs, such as other membrane systems and self-supporting prismatic tanks, compete for newbuild orders. Some owners favor variants that promise slightly lower boil-off or simpler construction, but many still return to NO96 because it has a long track record across dozens of ships.

Analysts who follow LNG shipping often point out that containment choice influences ship resale values and charter rates. A carrier with NO96 tanks fits easily into existing operational practices and training, which can be a quiet but convincing argument for a charterer who wants predictable risk. Over time, that preference feeds back into yard order books and GTT’s licensing revenues.

Regulatory and safety context

Safety rules around LNG transport are strict, and the NO96 system has been developed in dialogue with international maritime regulations and classification society rules. Designers must demonstrate that the membranes can withstand thermal cycling, sloshing loads, and emergency scenarios such as partial tank filling in rough seas.

In drills, crews simulate failures by closing valves or adjusting setpoints while the ship’s control systems respond. Even though the membranes themselves are out of sight, their behavior is reflected in how pressure curves react and how quickly alarms clear after disturbances. The containment system’s job is to turn potential chaos into manageable data and controlled responses.

Environmental and efficiency angle

Environmental pressure on fossil fuels has pushed LNG operators to look closely at transport efficiency. Lower boil-off rates mean fewer unintended emissions and better use of the cargo. The NO96 containment system contributes by reducing unplanned losses, complementing modern propulsion systems and hull designs that aim to cut overall greenhouse gas output per unit of energy delivered.

Shipping companies also weigh lifecycle impacts. Building a NO96 tank involves plywood, insulation materials, metals, and adhesives, all with their own footprints. Over a ship’s life, however, the extra cargo capacity and reduced losses can offset some of that initial impact when compared with alternatives that either carry less LNG or waste more through boil-off.

How the product fits into GTT’s portfolio

Within GTT’s line-up, the NO96 containment system is a cornerstone technology, often paired with digital monitoring tools and advisory services. Together, these offerings create a package for shipowners: hardware that keeps LNG in place and software that helps crews watch performance and plan maintenance. That mix supports recurring revenue through licenses and technical support.

For investors, NO96 represents stability. While new designs may target niche segments, classic membrane systems that have sailed for years form the base of GTT’s business. Orders for new LNG carriers or floating storage units frequently cite NO96 or closely related technologies, signaling continued demand in a market shaped by long-term energy contracts and infrastructure projects.

Stock context and listing

Gaztransport & Technigaz SA is listed in Paris, and the FR0011726835 ISIN identifies its securities on Euronext. The NO96 containment system, as a mature product, underpins a substantial portion of the company’s licensing and engineering income. On 2026-06-28, the price of Gaztransport & Technigaz SA shares can be checked on Euronext in euros as part of regular trading data from the exchange.

This article was AI-assisted and editorially reviewed. Product information without guarantee; prices and availability may change at short notice. No investment advice, no buy or sell recommendation. Stock-market transactions involve risks up to total loss.

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