DNV GL awards Robert Allan Ltd. first AIP for LNG-fueled pushboat

(HOUSTON and NEW ORLEANS) — The international accredited registrar and classification society DNV GL has presented Canadian naval architecture firm Robert Allan Ltd. with an approval in principle (AIP) for a natural gas fueled shallow draft pushboat design, the RApide 2800-G.

The rapid expansion of the LNG (liquefied natural gas) industry and the rise in unconventional gas production has revolutionized the gas sector in recent years. The increased availability of LNG has given operators realistic opportunities to add less carbon-intense vessels to their fleets which at the same time emit almost zero sulfur and particulate matter.

DNV GL’s most recent forecast predicts that by 2050 over 20 percent of total shipping energy will be provided by LNG. The RApide 2800-G is an innovative new design incorporating "pure gas" main engines, eliminating the need to use diesel fuel at any point during operation. The AIP validates that the vessel design is fully compliant with DNV GL Rules for Classification: Ships (RU-SHIP) and the International Code of Safety for Ships using Gases or other Low-flashpoint Fuels (IGF code).

“We are honored to receive this AIP from DNV GL. It is a demonstration of the excellent cooperation among the project partners throughout the challenging design development process,” said Pedro Ventura, contracts manager at Robert Allan Ltd. “Energy efficiency has always been a focus of our design efforts, and with the worldwide demand for lower fuel consumption and lower emissions, we have increased our focus in this area.”

The configuration is based on Robert Allan Ltd.’s RApide 2800-Z2 – a proven vessel currently operating on the Amazon River system. The new design was further developed in close cooperation with Rolls-Royce for its product brand MTU, incorporating an LNG propulsion system comprised of two 746-kW MTU 8V4000M55R-N IMO Tier III gas safe main engines and an LNG tank system with integrated control, safety and monitoring systems. The system uses two independent tank connection spaces attached to the LNG tank to ensure safety and redundancy.

While keeping the existing hull form, the arrangement was reconfigured to allow the installation of the LNG tank and associated equipment while still accommodating auxiliary machinery and continuing to provide a comfortable work environment for the crew. Despite the vessel’s compact size, the Approval in Principle confirms the concept is feasible and meets DNV GL’s rule requirements as well as that of the IGF code. This required comprehensive design efforts undertaken successfully by Robert Allan’s design team.

By Professional Mariner Staff