By ED FINKELSTEIN
How do you remove a worn out five-story, 59,000 pound cylinder with 141 attached tubes weighing 2,700 pounds each from a 17-story boiler at Ameren Missouri’s Labadie power plant and out of the building housing it when the 40-year-old equipment was never intended to be removed for repair in the first place? And then reverse the process to re-install new equipment?
Answer: You call on Nooter Construction and the skilled members of Boilermakers Local 27, who provide:
- Skilled craftsmen – Local 27’s highly skilled and trained union boilermaker welders were able to work in incredibly tight spaces, working two, 10-hour shifts a day to finish a job in record time. That was important, because the Labadie unit generates 640 megawatts of electricity for 250,000 homes and businesses each day. Ameren staggered shutdowns at its other energy centers while the boiler was down to ensure that none of its customers were without power.
- Skilled engineers – Nooter’s skilled engineers planned and executed the complicated upgrade of essential boiler components, including removing the 59,000-pound, 20-inch diameter cylinder and welded 141 six-inch u-shaped pipes, measuring several feet across and weighing 2,700 pounds each from the five-story building, despite the fact that the building was not designed to allow for the equipment’s removal.
- Communication – The Nooter and Ameren staff have a great working relationship with the Boilermakers. They understand one another, said Nooter Project Manager Bob Davis. “That’s critical on a job like this. The union really worked with us to get the manpower we needed.”
Boilermakers Local 27 Business Manager/Secretary-Treasurer Eugene Gill said the retrofit was a major success for everyone involved.
“We’re proud of the work our guys did,” he said. “It required special skilled welders working in extremely tight spaces to complete over 2,000 critical welds.
“When the union, the owner and the contractor come together with a plan, success is bound to happen,” Gill said. “That’s been our experience not only with Nooter, but other companies we work with as well.”
To get the project done last fall, Ameren Missouri turned to Nooter Construction and the skilled members of Boilermakers Local 27 to replace the working guts of the first of Ameren’s four boilers at Labadie while still producing one-quarter of the plant’s total electrical output.
The job had to be done quickly, safely and correctly the first time. But there were some substantial challenges to overcome:
- Timing – Because of demands for heating in the winter and air conditioning in the summer, major energy producers like Ameren have to do major repair or maintenance work during slow demand periods – spring and fall. Thus, every major energy supplier wants to do major repairs basically at the same time. That’s good for the contractors and their employees, but bad for the energy suppliers
- Manpower - There were a number of area projects requiring welders at the same time last fall when the Labadie boiler upgrade began.
To provide all of the skilled hands the project required, Local 27 called on its sister Local 363 in Belleville, and worked with its International Union to bring the needed skilled craftsmen in from other parts of the country.
- Cooperation – Local 27 was providing manpower a number of simultaneous jobs simultaneously jobs last fall. Fortunately, the union has a positive working relationship with its other contractor construction firms, and was able obtain cooperation from those firms to move specific skills sets off other jobs and move those men to Labadie.
- Special equipment – Because of the size of the components that had to be moved, Nooter needed help. Alberici Constructors had heavy cranes on site for other work and was able to provide the needed equipment to move the 59,000-pound cylinder (the Superheater Header) and the 141 five-story, 2,700-pound u-shaped pipes (Superheater Pendants).
The pendants move wet steam into the header, which superheats it to drive the turbines, which power the generators that produce electricity.
GETTING EVERYTHING OUT
Since the 40-year building housing the boiler was not designed to allow for major component replacements, several structural changes had to first be made to the building itself to make the retrofitting possible. This included punching large holes in the building through which the old equipment could be removed, and the new equipment installed.
This was even more complicated than it sounds.
Nooter Project Superintendent Mike Stechmesser said the pendants had clearances as small as one foot at times.
“Think of the pendants as a big sheet of paper six inches think, several feet wide and about 50 feet (five-stories) long,” Stechmesser said.
“It was a challenging path getting those old pendant assemblies out,” said Ameren Missouri Project Engineer Jim Schmaltz. “And we needed to get the new ones in without bending or damage of any kind.”
Once all the old equipment was removed, the new Superheater Header had to be installed. Then, the 141 five-story pendants had to moved into the building, lifted into the boiler and welded onto the header, with very little room in which to maneuver.
“These were less than ideal working conditions – very, very tight spaces,” said Labadie plant Director David Strubberg. “That made the re-installation task that much more difficult, but the boilermakers did it.”
SAFE AND ON SCHEDULE
Despite these and other complications, the experience and expertise of the boilermakers and Nooter staff allowed the $13.4 million project to be completed a day ahead of its 45-day schedule, without a single injury.
“The safety of this project was wonderful,” Davis, the Nooter project manager said. “Safety is a big concern with Nooter. While other contractors say it, Nooter lives it.”
Of course, the training and skill of the boilermakers plays a big role in maintaining project safety.
Davis said the company has completed 22.3 million man-hours of work without a lost-time injury.
Because of their efficiency, Ameren was able to take advantage of the shutdown by having Nooter and Local 27 boilermakers complete an additional 15,000 hours of other preventative maintenance on the boiler, adding almost $2 million dollars to the total cost.
How it works
Step 1 - The 17-story boiler first heats water to 550 degrees Centigrade to produce saturated wet steam.
Step 2 - That steam is pushed through 141 huge, five-story tall tubes called pendants and into the Superheater Header, where temperatures soar to 1000 degrees (under 2400 pounds of pressure per square inch) creating thermally efficient dry steam.
Step 3 – This ‘dry steam’ drive turbines.
Step 4 - The turbines turn generators that then produce our electricity. [/box]