In order to satisfy a higher demand for “green” and “blue” ammonia in the fertilizer industry and the energy sector, the supply and distribution of ammonia is significantly increasing and is expected to constantly accelerate in the next decade. In this perspective, new ammonia terminals will be required and must be designed with respect to social and environmental challenges, as well as local permitting regulations and safety requirements. Saipem has developed a wide range of solutions to tackle those challenges and requirements by offering large-scale Liquid NH3 storage (LNH3) and import/export terminal facilities supported on Gravity Based Structure (GBS). The GBS consists of a concrete hull, laid on the seabed in the near shore. It can contain a portion of the plant inside its hull and the remaining portion on its top slab, including the ammonia production or cracking facilities and relevant utilities, required buildings and the direct berthing and mooring facilities of large vessels. Saipem GBS solutions are flexible and adaptable to the project specific needs. Most of the construction activities can be performed in a safely protected and well-controlled work environment, whether at the GBS construction yard or in the fabrication yards of topside modules, LNH3 tanks and other large mechanical outfitting elements. The GBS concept allows the entire integration of the LNH3 storage system inside a single concrete hull, fully enclosed within multiple barriers of concrete structure, implying inherently safer solutions compared to the conventional onshore systems. In case a production of clean hydrogen is required, an ammonia cracking plant with zero CO2 emissions can be installed on the topside of a GBS, acting thus as an import terminal of clean ammonia and export terminal of clean hydrogen. This solution is highly effective, particularly in Europe, considering the expected increase of ammonia import and the high demand for clean hydrogen. Sequel to the completion of GBS civil works and the integration of topside modules, the GBS can be floated-out from its construction yard, towed, positioned, and sunk at its installation site with very minimal on-site works (permanent ballasting, hook-up, commissioning, and ready-for-start-up). As well, the GBS design can be reproduced with limited customization and GBS can even be relocated at any instant during the service lifecycle due to the classical ballast system with quasi-free maintenance cost. This article presents some projects which build on Saipem’s EPC expertise to design and construct large-scale nearshore GBS with cryogenic storages, such as LNG,
and LNH3.