LNG

Clean Jacksonville LNG Bunker Barge

HEC/GTT Original Design

HEC/GTT Original Design

It is always interesting to follow the development of our designs through to build and eventual operation. In this case this bunker barge began life in 2013 as a concept design project for GTT.

The GTT Demonstrator Mark III LNG bunker barge was designed to demonstrate the use of the GTT Mark III membrane containment system in an unmanned LNG Bunker barge.  This design demonstrated the feasibility of how the GTT Mark III containment could be used on a small scale, in a compact barge arrangement and meet all the handling requirements in a safe, reliable and cost effective manner.  

It was based on general requirements at the time for the markets for LNG bunkering in near coastal and inland markets.  The capacity is based generally on what these markets may require for refueling multiple smaller vessels (tugs, OSV’s, etc.) and larger ships that serve shorter (Jones Act) voyages.  The barge could operate as a mobile refueling resource (taking the fuel to the vessels) or moored/tied up to serve as a refueling station. 

Features of this concept can be scaled up to other services and vessel types as required by the trade being pursued.

One of the most important features addressed with this Demonstrator LNG bunker barge design is the manner in which boil off gas from the Mark III atmospheric tank is handled to provide safe operation over a market viable voyage profile.  All key regulatory requirements for design and operation were considered, including loading, discharge, transit, and emergency situations.

LNG Bunker Barge.jpg

HEC worked on structure, hull lines, design of the cargo handling system considering initial tank gassing up and cool down, LNG loading, idle mode, LNG offloading, tank warm up and inerting and boil off gas management. Also considered were hazardous area zones, protective location requirements for the LNG tanks, emergency shut down system, fire fighting, docking arrangement, fendering, ballast for trim and heel control, load balance and generating capacity.

ABS granted approval in principle in March 2014, followed by DNVGL in June 2014.

In February 2015, GTT North America received an order for the barge from Wespac Midstream LLC and Clean Marine Energy LLC to be built at Conrad Orange Shipyard, Inc. to serve Tote's new LNG powered container ships. At this point, GTT had added a GTT Reach4 LNG bunker mast as seen below.

Credit: GTT

Credit: GTT

Conrad Industries and their design contractor Bristol Harbor Group proceeded to develop the design, including large service and work spaces for equipment operators and a larger hose handling crane.

Jax LNG, who will be the operator of the barge, received their license to conduct ship to ship LNG bunkering operations in August 2017, and it is understood that the barge was delivered at the end of 2017, to commence bunkering in early 2018.

Credit: LNG World News

Here are some details of our other LNG projects.