Heavy-lift world record holder wins OTC Spotlight Award

China’s Yantai Raffles Shipyard recently unveiled a new heavy-lift gantry crane that has been garnering industry awards and breaking heavy-lift records. The Taisun crane is capable of lifting 20,000 metric tons and promises to improve safety, speed, and efficiency during construction of offshore production vessels. These accomplishments garnered the Taisun a Spotlight on New Technology Award at this year’s Offshore Technology Conference (OTC) in Houston, Texas.

The Taisun, which means “leading peaceful mountain” in Chinese, consists of two fixed beams, spanning the entire width of the 120-m dry dock and capable of lifting 10,000 metric tons apiece. A total of 96 unique lifting devices are present on the two beams (48 on each beam), which allow for many more connections pins to be mated to a deck box (384 vs. 4, which is typical for pedestal cranes). This reduces the force for each connection point dramatically, such that stress levels within the deck box structure during the lifting operation are 30% below design stress, even without any modifications to the original structure.

Yantai Raffles reports that its new gantry crane will allow entire semisubmersible deck boxes to be lifted onto their pontoons in one activity, rather than having to lift separate components of a deck box in separate stages.

Lifting an entire deck box after full assembly also provides significant savings in man-hours and substantial safety benefits. By allowing the deck box to be assembled closer to the ground, worker safety is increased and additional requirements for working at height are dramatically reduced, which Yantai Raffles says will cut overall project man-hours by up to 2 million.

Conducting a single lift to connect platforms to their pontoons in the shipyard also eliminates many of the logistical and safety challenges with conventional mating operations at sea. Compared to floatover installations, in which the platform deck is floated over the pontoons that have already been installed on location, a Taisun lift does not require a number of separate installation barges and other vessels. This eliminates the need to integrate and coordinate the movement of different vessels and negates the possibility of impact risks in choppy waters.

During a christening ceremony in April at the shipyard located in Shandong Province, the Taisun hoisted a launching barge weighing 20,133 metric tons 30 m above the water, a new heavy-lift world record. The American Bureau of Shipping (ABS) was on hand to witness the lift, and presented Yantai Raffles with a “Witness Load Testing” certificate, confirming the capacity of the Taisun at this lifting weight.

Based on the promise this new gantry crane holds, the organizers of OTC presented Yantai Raffles with a Spotlight Award, one of fourteen awarded this year. In order to win the award the Taisun met four technology criteria:

• New and innovative -the technology must be less than two years old and must not be in violation of any known patents.
• Proven -the technology must be proven through full-scale application or successful prototype testing.
• Broad interest -the technology must have broad appeal for the industry at large.
• Significant impact -the technology must offer substantial benefits over current technologies.

The Taisun also received the Woelfel Best Mechanical Engineering Award, conferred by the American Society of Mechanical Engineers (ASME). This award recognizes technologies which are novel; have a significant impact on the offshore industry; meet health, safety, and environmental standards; and are well conceptualized and developed.

At an OTC press conference, Yantai Raffles’ Chairman Brian Chang said that the first commercial semisubmersible lift for the Taisun is planned for the second half of 2008, and clients are lining up for future lifts. “We have thus far booked a total of nine semi lifts (each between 10,000-16,000 metric tons) and one accommodation unit lift (8,000 tons). Beyond this, we want to bring the value of our new crane to other yards, and expand to FPSO construction as well.”

Chang expressed optimism that the Taisun will prove itself quickly to the heavy-lift market, and confidence that further construction efficiencies are possible. “Over the past 20 years, time-to-market for semisubmersibles has not significantly improved, but now we have a heavy-lift option that reduces total man-hours by 25%. I am sure that once the Taisun is in full commercial service, we will learn from our experiences and be able to further improve time-to-market.”

To learn more about Yantai Raffle’s Taisun gantry crane, visit www.yantai-raffles.com.

Ted Moon is the Technology Editor of JPT Online. He brings information on emerging technologies, R&D successes, new field applications, updates from SPE papers about recent innovations, and more. If you have a question or suggestion for future article topics, email Ted at teched@spe.org.