GH has used austenitic steel with a special grade for LNG containment since its approval by Bureau Veritas in June 2022, as an “alternative material” with respect to the IGC and IGF Codes. The compatibility of this material with ammonia has been verified by a specific Stress Corrosion Cracking test performed by GH and then approved by Bureau Veritas in August 2022.

Another innovative development increasing flexibility when it comes to fuel choice is a new design that will allow shipowners to convert steam powered vessels to hybrid dual-fuelled propulsion.

Lloyd’s Register (LR) has awarded Approval in Principle  to Empresa Naviera Elcano for their patented steam-to-hybrid conversion design for the transformation of steam turbine LNG carriers to a dual-fuelled propulsion system. 

The transformation consists of a modification to the propulsion and electrical power generation system, upgrading the vessel from steam powered to a hybrid system with a steam turbine and dual fuel generator. The dual fuel generator will supply electrical power to the ship’s switchboard with electric propulsion motor/s coupled to the ship’s propulsion gear box/shaft. The hybrid system also includes devices that can recover energy from the dual fuel generator exhaust gases and engine cooling systems, which will be integrated into the existing steam plant systems. 

The conversion could benefit the one-in-three LNG carriers that rely on steam propulsion and are currently at risk of being non-compliant with the IMO’s EEXI and CII regulations, without the need to scrap any part of the original steam propulsion system. 

Elcano’s solution will ensure the steam turbine LNG fleet will meet EEXI MARPOL regulations by substantially reducing greenhouse gas (GHG) emissions on converted vessels, prioritising both energy security and climate alignment for the maritime industry.  The company says that emission reduction and energy savings will increase dramatically if a vessels conversion includes the retrofitting of a reliquefication plant driven by a dual fuel generator. This will increase efficiency by minimising the vessels use of a steam dump system.