On a 500Kv Power Transmission job site in Arkansas the contractor described the following scenario where the Tadano Mantis greatly increased his productivity and shortened the installation time of dampeners and spacers on a high-voltage line:
The contractor had to install 1800 dampeners, designed to reduce line vibration in high winds, every 15 yards on these lines. He had a 21 day window of time with the power shut off to accomplish this. Using a Tadano Mantis crane with a Work Platform attachment the crew had one man on the ground walk under the lines and plant marker flags every 15 yards. The crane operator followed with the boom parallel to the ground and workers in the platform. They stopped at each flag, boomed up, and the crew installed the dampeners. Then they would boom down, walk the crane to the next flag, and repeat the procedure. By using this method, and taking advantage of the Mantis’s ability to lift without using outriggers, the contractor was able to install 100 dampeners per day and complete the task in 18 days.
We asked the contractor to describe how they would have done this job if they did not have a Mantis. We also asked him to compare the productivity. He said they would have used a tracked utility machine with a work platform. Their procedure would have been similar, except that they would have had to carefully position the machine, deploy outriggers, and then boom up. He indicated that with the additional time needed to position the machine, and deploy and retract outriggers, he would have been able to install only 20 dampeners per day and would have needed 90 days to accomplish the same task. Alternatively, he would have probably used more machines and crew to accomplish the job within the 21 day time limit.
The contractor indicated that he uses Mantis cranes and the same methods described above to install spacers on high-voltage lines.
