Floating gas pipeline solution

CNG Optimum

GEV’s CNG Optimum ship is the next generation of Marine CNG  transportation and the result of two decades of developing a low-cost, volume efficient CNG ship design. The CNG Optimum ship is now construction ready with GEV seeking to commercialise CNG projects using an integrated ‘Pipe to Pipe’ Business Model which includes loading, shipping and unloading.

The CNG Optimum ship design maximizes the amount of Compressed Natural Gas that can be stored within the hull of a ship, with a capacity of 200 million standard cubic feet. The Optimum containment system is constructed using hexagonal close-packed, high strength pipes that run the entire length of the ship’s cargo hold. The simplicity of the design and the invention of a mechanism to clamp the gas storage pipes so tightly together that they become locked together as one, allows this design to meet all classification requirements.


American Bureau of Shipping (ABS) issued its formal letter in January 2019 granting approval for construction of the CNG Optimum ship as designed, subject to continued compliance with applicable ABS Rules and Guidelines. Approval of the CNG Optimum ship design follows the completion in December 2018 of the extensive work program including; prototype testing of the Optimum system, review and verification of the design, review of the safety studies and a Hazard and Operability Analysis (HAZOP). Granting of the letter of approval by ABS is a major milestone for GEV and the culmination of three years of effort.

Base CNG Optimum ship design with principal particulars per CIMC Raffles general arrangement drawings.

CNG Optimum ship designed for offshore loading applications. CNG ship is equipped with bow thrusters as part of Dynamic Positioning (DP) requirements and compatible to load gas via a Submerged Turret Loading (STL) system or Single Anchor Loading (SAL) system. The preferred loading system is subject to met-ocean conditions, particularly wave height.

CNG Optimum Design & Construction Partners


GEV’s shipping team is supported by a team of global experts in the design and construction of the CNG Optimum ship, including Clarksons Platou as our Ship Broker & Financial Advisor, SeaQuest Marine as our Lead Technical Consultant and Yantai CIMC Raffles Offshore as the Shipyard for construction.

In July 2019, GEV entered into a Letter of Intent with Yantai CIMC Raffles Offshore to build the CNG Optimum 200MMscf ship. 

GEV and CIMC Raffles will now work towards a binding shipbuilding Engineering, Procurement & Construction contract, employing GEV’s CNG Optimum design, for 4 firm CNG Optimum ships, with the option for GEV to order up to an additional 4 ships.

The selection of CIMC Raffles has been driven by the commercial terms under the LOI. CIMC Raffles has a strong track record, delivering in excess of US$6 Billion in EPC contracts since 2012. CIMC has the required gas expertise, large in house design and gas handling department having built the first and only marine CNG carrier in 2016.

Emissions profile

Environmental Benefits

CNG Optimum holds the potential to commercialise a new global industry for the bulk transport of natural gas in regional applications. Natural gas is a vital component of a sustainable energy future, being the transition fuel to renewables.

CNG Optimum ships will be among the cleanest running in the world, equipped with dual fuel engines which run on natural gas from their own cargo.

  • The CO2 equivalent emissions profile of GEV’s CNG Optimum transport solution has been peer reviewed by leading professional services company GHD.
  • When the full fuel cycle of compression-shipping-decompression is assessed, GHD agrees that for transporting 200 MMscf/d of gas over a distance of 500 nautical miles, CNG is a lower emissions intensive process than transporting the gas as LNG by a factor of approximately 3-4x .
  • As global oil and gas producers increasingly refocus their business plans to attain a ‘net-zero’ target, a cost competitive, low emission marine gas transport solution will enable companies to reduce their emission profile whilst maximising the economic value of their gas fields.