Harvey Gulf International has awarded a contract to Wärtsilä to supply liquified natural gas propulsion equipment for two of Harvey Gulf’s newbuild offshore support vessels for operation in the Gulf of Mexico. Once completed, the supply vessels will be the first ever U.S.-flagged offshore supply vessels to be powered by LNG.
The OSV’s will be based on the STX Marine Inc SV310DF design and are to be powered by Wärtsilä 6-cylinder 34DF dual-fuel engines. The vessels, with LNG storage capacity of 290 cubic meters (m3), will have more than a week of vessel operational time. In addition, the vessels will have the capacity to carry 5520 tons of deadweight at load line and have a transit speed of 13 knots.
The Wärtsilä 34DF engine is capable of running on either gas or diesel fuel with full EPA emissions Tier 2compliance. When running in gas mode, NOx emissions are reduced by some 85 percent compared to diesel operation. Furthermore, Sulphur oxide emissions are completely eliminated and emissions of CO2 are also lowered. The contract includes options for supplying propulsion equipment for additional follow-on vessels.
In addition to being powered by cleaner burning natural gas, the vessels will achieve “ENVIRO+, Green Passport” Certification by the American Bureau of Shipping. The requirements for this certification include, among others, that the vessels be continuously manned with a certified Environmental Officer, be completely constructed with certified environmentally friendly materials, and have advanced alarms for fuel tanks and containment systems. Along with Harvey Gulf’s other vessels under construction, they will be the first OSV’s to achieve this certification, making them the most environmental friendly OSV’s in Gulf of Mexico.
The OSV’s are reportedly being built by Trinity Offshore, a subsidiary of Trinity Yachts Corporation, at Trinity’s Gulfport, MS yard. The vessels are scheduled for delivery in 2013 and will operate in the Gulf of Mexico.