Follow me down the Tennessee: Alstom Ships First Gas Turbine from Chattanooga

Issue 7 and Volume 116.

GT24 gas turbine
In May, Alstom shipped the first GT24 gas turbine from its manufacturing facility in Chattanooga, Tenn. Photo – Brian Wheeler.

By Brian Wheeler, senior editor

In early May, Alstom shipped the first GT24 gas turbine from its manufacturing facility in Chattanooga, Tenn., an important milestone for the French-headquartered power generation technology provider.

The 230-ton, 60-Hz GT24 turbine, heading to the El Sauz CFE combined-cycle power plant in Mexico, left Chattanooga by way of the Tennessee River en route to New Orleans, where ACS Cobra, Alstom’s customer, will take possession of the unit.

Alstom was awarded the contract in 2011 to supply the new turbine, which, along with a new heat recovery steam generator (HRSG), will replace three existing GT11 turbines at El Sauz.

“This is a great day for Alstom,” said Lawrence Quinn, president of Alstom Chattanooga Turbines LLC. “It really was a team effort.”

Alstom will also retrofit the station’s steam turbine, resulting in a 20 percent increase in efficiency, said Patrick Fetzer, regional vice president for Alstom’s gas power plant business in North America.

“The natural gas-fired power generation market in the U.S. is forecasted to grow substantially in the next years,” said Fetzer. “Our first gas turbine shipment marks the readiness of this facility to become a manufacturing hub for Alstom turbines in the U.S.”

Fetzer said retrofitting steam turbines makes it easier to receive proper permits, since critical components, such as the generator and condenser, are reused. The retrofit reduces emissions while increasing output.

“We must take advantage of existing plants,” he added.

At the El Sauz station, Alstom’s Service business line will monitor the delivery of the GT24. The Service division, which has the capability of completing full construction, will also observe commissioning of the GT24 to make sure performance guarantees are met.

“I have built many power stations in many places around the world,” said Quinn. “There is nothing better than seeing a job finished.”

Starting Up

Opened in 2010 after announcing construction plans in 2007, the 35,000-square-foot facility in Chattanooga was built to manufacture steam turbines, gas turbines and related equipment for the North American power generation market. The facility is also being used to retrofit existing turbines for fossil and nuclear plants.

The $300 million investment in Chattanooga boasts some of the largest production possibilities in the world. With an 8 MW drive motor and a maximum weight capacity of 350 tons, the rotor balancing facility will help manufacture the largest turbines in the world.

“We invested in America for good reason,” said Quinn.

All finished rotors will test at a 20 percent faster speed than what will be used in operation at the plants. For full-speed 60-Hz gas-fired turbines, the rotors will spin at 4,500 rpm, while in the operating power plant they will operate at 3,600 rpm.

For nuclear turbines, such as the Arabelle 1,700 MW class steam turbine, operational speed is typically 1,800 rpm, so Alstom will test at 2,200 rpm. The balancing facility used 10,000 cubic yards of concrete, 2,000 tons of re-bar and 1,720 tons of steel. The rotor machining area has one vertical lathe, three horizontal lathes and two horizontal boring and milling machines. One of the horizontal turning lathes, also the largest in the industry, can handle a maximum rotor diameter of 7,000 mm and a maximum weight capacity of 350 tons. The GT assembly line is where the GT24 gas turbine is manufactured.

“We now have the opportunity to take on more than just the retrofit of nuclear,” said Quinn.

The facilities’ high bays have 15 cranes, one for each turbine in production. The largest cranes can lift 500 tons, sufficient to move any finished turbine. In the casing line, the largest crane capacity is 300 tons. During intermediate manufacturing, there are numerous 150-ton cranes to contribute to the lifting capacity.

Quinn said Alstom has invested over $10 million in training of employees for the multicultural environment at the Chattanooga facility by building off knowledge and lessons learned from their colleagues at other manufacturing facilities in Poland, Germany, Switzerland and France.

“This being the first gas turbine going out the door, we had to make sure that we were able and could commit to the entire scope which we took on,” said Quinn. “And this would not have been possible without our peer networks.”

Utilizing the knowledge and training from facilities abroad has helped make the transfer of technology to the Chattanooga facility less risky.

“The men and women watching this machine leave our factory (May 8) have worked hard to ensure our first gas turbine sends a strong signal to the marketplace about Alstom’s U.S. capabilities,” said Quinn.

The El Sauz GT24
The El Sauz GT24 being loaded onto a barge for shipment to New Orleans. Photo courtesy Alstom

In 2011, Alstom introduced its next generation GT24 gas turbine and complimentary KA24 combined-cycle power train, committing to the growing gas-fired power generation market in the U.S. In a 2-on-1 configuration, the GT24 can generate more than 700 MW with an operation efficiency of more than 60 percent.

“The GT24 is built in the U.S., for the U.S. market,” said Fetzer.

Alstom is building the GT24 for the growing demand for power in the U.S. and the hope of a revival of the economy. While the planned nuclear renaissance in the U.S. may not be coming along as some envisioned, Alstom still views nuclear as a vital role of its business.

“Nuclear will come back, strategically,” said Quinn.

In August 2011, Alstom, from this same facility, shipped two new low-pressure nuclear steam turbine rotors. The shipment of the rotors, which were bound for a nuclear power plant in Illinois, was the first time Alstom shipped completed units from the Chattanooga facility via the Tennessee River. With access to the Tennessee River, using a 509-ton crane, Alstom can reach 80 percent of all U.S. nuclear power plants, said Quinn. The riverside site, which was once home to Combustion Engineering, was the shipping location for 99 reactor vessels prior to Alstom’s buyout of Combustion Engineering’s fossil and boiler businesses.

Workers prepare the El Sauz gas turbine for its journey to New Orleans.
Workers prepare the El Sauz gas turbine for its journey to New Orleans. Photo courtesy Alstom

Each rotor shipped in 2011 was 35 feet long, weighed 130 tons and stood 15 feet tall. En route to the Illinois nuclear plant, the barge-carried rotors made their way down the Tennessee, Ohio, Mississippi, and Illinois Rivers.

Alstom will also be able to reach power plants across the U.S. with the use of Chattanooga’s mature rail hub and interstate highway infrastructure.

Alstom has now shipped seven rotors and one gas turbine from the Chattanooga plant. Quinn’s philosophy, as the man-in-charge in Chattanooga, is simple: Do the job correct the first time, and do it safely.

“We have never been late to schedule,” he said. “And we don’t intend to be.”

Quinn said the Chattanooga facility has orders logged for fossil retrofits, and two gas-fired units in the factory, with more orders expected from all facets of power generation. And while new nuclear continues slowly in the U.S., Quinn said Alstom will continue to assist nuclear operators to increase the amount of power existing plants generate.

“We anticipate a huge load ahead for us,” said Quinn.

As the Alstom team in Chattanooga looks forward to their next order, the first step of the journey, Quinn said they will be self-reliant to complete the order form start to finish.

Alstom has plans to expand its footprint in Chattanooga to continue to be efficient in the production of gas and steam turbines.

“(This facility) is on the verge of being something extremely special,” he said. “As the power market bounces back, we are going to grab it with both hands.”

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