Design of lng tank Type C

  • 1 University of Zagreb, Faculty of Mechanical Engineering and Naval Architecture, Zagreb, Croatia


Cylindrical tank-type c is designed for cruise passenger ships trying to adopt hull space and meet the requirements of propulsion. Tank must be a double wall with the vacuum space in between, which is also fulfilled with the perlite as insulation. The main input for the design was a tank capacity of 430 m3, vapor pressure, and available space inside of hull structure. The holding period of the boil-off gas is limited to 21 days of ship voyage. Trying to satisfy the volume capacity of the inner tank different dished end of tank was observed. The inner tank is divided into segments for the calculation of hydrodynamic pressure. According to classification rules, dnv and igc rules tank thickness, supports, stiffening and vacuum rings are determined to satisfy bending and buckling requirements. Some of the requirements were according to british standards for validation of the results. The material that is used for calculation is stainless steel 304 l. The main goal of this paper is to provide the optimal design of the lng tank type c considering the mass of the whole lng tank, with attendance to reduce the steel mass of the structure by optimizing shell thicknesses and the number of vacuum rings. After analytical calculations are made finite element analysis is used for verification of the given results. According to the given results space for improvements of tank-type c was observed.



  1. IMO International Code of Safety for Ship Using Gases or Other Low-flashpoint Fuels (IGF Code), (2015)
  2. Tommaso Iannaccone, Gabriele Landucci, Alessandro Tugnoli, Ernesto Salzano, Valerio Cozzani, Sustainability of cruise ship fuel systems: Comparison among LNG and diesel technologies, (2020)
  3. Ole.Vidar.Nilsen, LNG regulatory update, DNV-GL, (2018)
  4. American Bureau of Shipping, Strength Assessment of Independent Type C Tanks, (2022)
  5. Heewoo Park, Jinseong Park, Jong-Rae Cho, Evaluation of Insulation Performance and Structural Integrity of an IMO Type C LNG Storage Tank
  6. Banaszkiewicz T, Chorowski M, Gizicki W, Jedrusyna A, Kielar J, Malecha Z, Piotrowska A, Polinski J, Rogala Z, Sierpowski K, et al. (2020). Liquefied natural gas in mobile applications—opportunities and challenges. Energies. 13(21):1–35.
  7. IMO International code for the construction and equipment of ships carrying liquefied gases in bulk (IGC Code). London, (2016)
  8. J Harperscheidt , Bunkering, infrastructure, storage, and processing of LNG - Ship & Offshore, (2011)
  9. Yan Lin, Chao Ye, Yan-yun Yu, Shi-wei Bi, n Approach to Estimating the Boil-Off Rate of LNG in Type C Independent Tank for Floating Storage and Regasification Unit under Different Filling Ratio, (2018)
  10. Cheng Wang, Yonglin Ju, Yunzhun Fu, Dynamic modeling and analysis of LNG fuel tank pressurization under marine conditions, (2021)
  11. Sixian Wu, Yonglin Ju, Numerical study of the boil-off gas (BOG) generation characteristics in a type C independent liquefied natural gas (LNG) tank under sloshing excitation, (2021)
  12. Bo Wang, Yung-Sup Shin, Eric Norris, strength assessment of type ‘C’ LNG fuel tanks, (2015)
  13. Bo Wang, Xiaozhi Wang, Yung-Sup Shin, structural integrity assessment of independent type ‘C’ LNG carriers, (2014)
  14. Ivo Senjanović, Vedran Slapničar, Zoran Mravak, Smiljko Rudan & Ana Maria Ljuština, structure design of cargo tanks in liquefied gas carriers
  15. David Nash, Differences Between EN 13445 and Other International Standards, (2008)
  16. Young-IL Park, Jin-Seong Cho and Jeong-Hwan Kim, Structural Integrity Assessment of Independent Type-C Cylindrical Tanks Using Finite Element Analysis: Comparative Study Using Stainless Steel and Aluminum Alloy, (2021)
  17. DNV No .31.13 Strength analysis of independent type C tanks, 2016
  18. DNVGL-RU-SHIP-Part5 Chapter7 Liquified gas tankers, 2017
  19. DNVGL-RU-SHIP-Part4 Chapter7 Pressure equipment, (2017)
  20. DNVGL-RU-SHIP-Part5 Chapter5 Liquified gas
  21. DNVGL-RU-SHIP-Part2 Chapter2 Metallic materials, (2017)
  22. IMO. International code for the construction and equipment of ships carrying liquefied gases in bulk (IGC Code). London,2016
  23. John Kokarakis, Standards and Guidelines for Natural Gas Fuelled Ship Projects, 2015

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