LNG Grain: 190,000 m³ LNG Tank Project | Entrepose Contracting

Located at the mouth of the River Thames in Kent, England, the project involved the turnkey EPC delivery of a 190,000 m³ full containment LNG tank for National Grid Grain LNG. Entrepose Contracting led a VINCI joint venture with VINCI Construction Grands Projets and Taylor Woodrow. The scope covered engineering, procurement, construction, pre-commissioning and commissioning support.

Key project figures

• 190,000 m³ of storage capacity
• Approximately 92 m in diameter, with the roof reaching a height of 50 m
• 1,336 continuous flight auger piles
• A 9% nickel steel inner tank designed to contain LNG at -163 °C
• A horizontally and vertically pre-stressed concrete outer shell constructed using slipforming
• A steel dome assembled and welded at ground level, then raised into position by air pressure

This full containment configuration combines two complementary systems: a steel inner tank providing primary LNG containment and an outer concrete shell contributing to the overall safety of the installation.

One of the project team’s main challenges was managing a large number of closely interdependent interfaces. Although some activities could proceed in parallel, inadequate coordination in one area could affect other work fronts and create cascading delays. Controlling the activities and their interfaces was therefore essential to protect personnel, maintain quality and meet the schedule.

The tank was constructed within an operating LNG terminal, in an environmentally sensitive setting and with permanent interfaces with existing facilities. From the outset, the construction strategy incorporated HSE management, quality, schedule, weather conditions, constructability and continuity of supply.

With the project now complete, this campaign reviews the ten principal stages of its construction: slipforming, air raising of the dome, liner installation and pre-stressing, roof concreting, construction of the 9% nickel steel inner tank, equipment installation, testing, insulation, inerting and cool-down.

Coming next : continuous construction of the tank's external concrete wall.