GTT Mars, Technology for LPG vessels

GTT MARS, the technology for LPG vessels


GTT MARSTM is designed for the specific application of LPG transport. It is suited for a cargo temperature range from -55 °C to 0 °C.

The solution is based on a single membrane concept. The insulation is fitted on the inner hull of the vessel, which acts as the secondary barrier of the tank, and supports the primary barrier.
This primary barrier is made of corrugated stainless steel.

GTT Mars TM CCS design


Optimised storage space

As the containment system follows the contours of the hull, GTT MARSTM makes it possible to both carry more LPG than self-supporting solutions and reduces the weight of the vessel. The solution adapts to any shape and size of vessel.

An 84,000 m3 ship equipped with a self-supporting tank weighs 19,000 tons, compared to 18,000 tons for the same ship equipped with GTT MARSTM. The reduction in weight means cargo capacity can be increased: the 1,000 tons of steel saved translates to an extra 2,000 m3 of cargo.

Safety and reliability

The primary barrier, which is in contact with the cargo, has corrugations. The corrugation knots, located at each intersection, are designed to be able to fully unfold during an external event.


GTT Mars primary membrane

GTT primary membrane

GTT considers the construction risks when determining the design of the membrane technology.

GTT, DNV GL and the Hamburg University of Technology (TUHH) have tested, at a 1:1 scale, the behaviour of the primary membrane in case of a collision with another ship’s bow. The corrugations spread out entirely with no breakage or loss of tightness. The behaviour of the primary membrane under large deformations has been tested separately under cryogenic conditions yielding the same results as the large scale test.


Simplified cargo operations

  • Twice as less energy, and therefore LPG, needed to cool down the tank
  • Operation times are significantly reduced: 3-4 hours with GTT membrane technology compared to 20 hours for a self-supporting tank
  • Loading possible without cooling the tank in advance
  • Reduced ship detention time


+2,000m3 of cargo capacity on a 84 000 m3 VLGC (Very Large Gas Carrier)
17h saved per cooling-down operation
50 years of experience in membrane solution


GTT MARS - Video