It is supposed to be a textbook lift. The new 100-ton (91 t) capacity Link-Belt RTC-80100 Series II rough-terrain crane picks a prefabricated condenser unit from a flatbed trailer and raises it to a vertical position. Once off the flatbed, the crane rotates the 46,000-lb. (20,865 kg), 50-ft. (15 m) tall, 12-ft. (3.6 m) square structure more than 300 degrees and lowers the unit onto its foundation. However, what looks good on paper isn’t always the reality. Several adjustments had to be made in order to complete the lift.
Rocky Mount, NC-based Inco Inc. is contracted by the Panda-Rosemary Water Company to fabricate and erect a majority of the new Panda-Rosemary plant in Roanoke Rapids. The “out of the ground” facility that is being built on a “fast-track” method. The completion date is October 2002.
Panda-Rosemary Water is a wholly-owned subsidiary of Dallas, TX-based Panda Energy International. It is being designed and built to take advantage of the secondary product from the adjacent Panda-Rosemary cogeneration facility. That is a 185-megawatt natural gas fired plant built, at a cost of $140 million between 1989 and 1999, to supply electricity to the Virginia Electric Power Company under a long-term contract.
Inco’s Project Manager Chris Sandlin, Field Superintendent Ernest Jones, and Crane Operator Carroll Selby had checked the Link-Belt operations manual and consulted with the facility owner’s representative to make sure everything was ready. The condenser unit would be a tight fit. Not much room for error, but well within the lifting limits of the RTC-80100.
“The primary emphasis on any of our jobs is safety. It might take us a little longer, but we know that a job will be done right when an Inco crew makes a lift. The safety of our men and the customer’s property are the most important service that we provide. The president of our company wouldn’t have it any other way,” said Sandlin.
The pick is tight so Inco needs a drum of boom grease to slip the crane into position. The Inco crew slipped the new Link-Belt RTC-80100 crane between an existing 48-ft. (14.6 m) high, 750,000-gal. (2.8 million L) water storage tank and a hot (energized) transformer grid. It was not that easy in the confined worksite.
A nearby trench containing pipes connecting the new condenser unit with the water storage tank, and an evaporator was not fully compacted because the contractor had to install more process piping. As in Murphy’s Law, the trench was in the worst conceivable place — right under an extended outrigger pad.
There never was a question as to whether the new Link-Belt 100-ton (91 t) RT could make the 24-ton (22 t) lift unassisted. The question is whether the crane can be positioned and make the lift without the possibility of collapsing the trench. The contractor filled and compacted the trench. As an additional safety precaution, the decision was made to bring in a second Link-Belt crane, an HTC8670LB “Long Boom,” to take part of the initial load and force. This would prevent any possible damaging tail swing of the condenser unit during the initial lifting phase.
“We probably could make the lift, but we don’t work that way. It was the third of July and everyone was looking forward to the holiday. Why take a chance with safety when we had the time to do it right? We knocked off and came back to work after the holiday, bringing a Link-Belt HTC-8670L8 with us,” said Sandlin.
The bottom line was that the operator of the RTC-80100 safely made the initial pick to lift and load the condenser tower onto a flatbed transporter by itself. A second Link-Belt crane was brought in as a safety precaution during the erection pick. As soon as the tower was raised to vertical, the RTC-80100 completed the swing and positioning of the new condenser unit by itself.
Details of the lift include picking and placing a tower that weighs approximately 23 tons (21 t). The onboard computer in the Link-Belt RTC-80100 indicated an actual load weight of 46,400 lbs. (21,047 kg). The crane’s boom length was 95.2 ft. (29 m) at an angle of 70 degrees and a working radius of just more than 25 ft. (7.6 m).
The operator of the HTC-8670LB had more room to get into position. He used a 30-ft. (9 m) radius, 52-degree boom angle, with 58-ft. (17.7 m) of boom. At one time during the erection, the Link-Belt HTC8670LB crane was lifting 19,500 lbs. (8,845 kg), making sure there was no extra movement, and plenty of clearance from the water tower.
All of the units for this plant, with the exception of the 760,000-gal (2.9 million L) water storage tank, were fabricated in the state of Washington and trucked to North Carolina. The companion evaporator was installed several weeks after the condenser tower. In between that time, Inco erected the dome top of the new water tower with its RTC-80100 crane.
Completion was a day late, but the job was completed without incident and to standard. In fact, the possibility of serious damage was avoided. The soft, filled-in compacted trench was reinforced with large timber mats for the outriggers. The two-crane lift was performed without a hitch. The helper crane was cut loose when the load reached the vertical position and the new RTC-80100 made the final swing and placement unaided.
For more information, call 606/263-5200.
This story also appears on Crane Equipment Guide.
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