US-based Crowley Holdings has unveiled designs for its sixth heavy-lift deck barge, the 455-6, which is scheduled to be constructed and operational by 2013.

The boat is the third heavy-lift deck barge the company has planned this year.

The 455-series deck barges, with 25ft side shells, can accommodate large drilling and production units deployed for deepwater offshore energy development and exploration.

Crowley is also scheduled to deliver the 455-7 deck barge in September and the 455-8 at the end of the year, bringing the total number of heavy-lift deck barge deliveries in 2009 to five.

Crowley offers diversified transportation and logistics services in local and global markets through six operating lines of business.