Photo courtesy of Manitowoc Co. Inc.
The Manitowoc 31000, working here in South Korea, supports a maximum capacity of 2,300 tonnes and a load moment of 252,000 ft-kips.

After sitting idle through much of the economic downturn, Manitowoc's first model 31000 supercrane is hard at work in Gwangyang, South Korea, lifting pressure vessels for a coal gasification project.

"The Manitowoc 31000 has a tremendous capacity, and we will be able to use it for heavy lifts on a diverse number of projects," says Chang Hwan Jang, chairman of Korea-based Chunjo Construction Co., in a statement. The company purchased the 2,300-tonne-capacity machine for its crane-rental fleet.

According to Chunjo, the model 31000 will be available for contractors to rent worldwide. As part of the deal, the company also bought three 600-ton Manitowoc 18000 crawler cranes.

The Gwangyang project, which is managed by POSCO E&C, is a 500,000-ton-per-year synthetic/substitute-natural-gas (SNG) plant located near one of POSCO's steel mills. The project started in 2009 and is expected to wrap up at the end of this year.

Chunjo began assembling the giant crane about eight weeks ago, Manitowoc sources say. The first lift, a 280-tonne load, was performed on March 30. On April 3, it made a second lift of 480 tonnes.

In all, the coal-to-liquid-gas project is using the crane, which is set up with 55 meters of boom and 60 m of luffing jib, to perform 12 lifts on three of the plant's heavy vessels.

Sales of the Manitowoc 31000, unveiled at CONEXPO 2008, have suffered from poor timing: Although the company quickly obtained two orders for the roughly $30-million crawler crane, the U.S. economy collapsed as the machine went into production.

Contractors grew uncertain that they would be able to find enough work for such an expensive machine to pay off. Soon after, the 2011 Fukushima Daiichi nuclear-plant disaster in Japan further hurt the market for giant cranes, whose long arms are designed to lift building modules far over a jobsite.

Unique to the 31000 is a Variable Position Counterweight—essentially a floating counterweight wagon—that allows the crane to work in tight spaces with minimal ground preparation. The system's rack-and-pinion stinger extends from eight meters fully retracted to 29 m fully extended. The massive rig, which ships in about 125 truckloads, is powered by two 600-hp diesel engines.

According to a 2012 review by ENR, the model 31000 ranks as the world's eighth-largest supercrane.