Two Manitowoc Potain tower cranes have proved to be a good fit for the tight working spaces at the Haverly Apartments development site in downtown Phoenix. The cranes, an MD 485 top-slewing and an Igo T 85 A self-erecting crane, were strategically positioned and together able to reach every corner of the job site.
The project started with assembling the MD 485 on a cross base with just a few inches to spare in the building's small courtyard. Even though the crane has a 262 foot jib and 119 foot height under the hook, there was one corner at the job site that the MD 485 could not reach. Compass Equipment concluded another crane would be needed to complete the job to maximize job site build efficiency.
"The challenge with this missing area was that a second crane would have to fit into a very tight space with a lot of obstacles," explained Kelly Hadland, CEO at Compass Equipment, which provided the Potain cranes to the project. "For starters, it had to stay below the MD 485's jib yet be tall enough to clear the building with rigging and have room to place loads. Secondly, its footprint had to stay inside a 25 square-foot area right next to the building, as access to the jobsite for materials and construction had to remain open."
With such a limited working space, any crane outside the 25 square-foot footprint would have blocked machinery traffic and created a safety hazard. To make matters more challenging, job site obstacles were only 45 feet away from where the second crane had to be placed, yet some of the loads would need to be placed within 20 feet of them.
According to Hadland, it was critical that the second crane would be able to swing high above these obstacles and have zone restriction to prevent contact with them.
"With all those aspects to consider, I could only think about one solution: The Potain Igo T 85 A self-erecting crane," Hadland said. "With seven different height-under-hook options, we were able to set the height at a perfect spot that cleared the building and obstacles yet stayed under the larger tower crane, helping to keep productivity high while maintaining the factory's minimum clearance requirements."
The Igo T 85 A required only 22 square-feet of space. Workers were able to fit the crane into a small space right next to the building. Getting it into the precise location was a challenge the team solved by using its GAPO power unit steerable axle.
"No mobile crane could possibly have worked, and to the best of our knowledge, no other model of self-erecting tower crane could have met all the other criteria," Hadland concluded. "Self-erecting tower cranes are proving themselves more and more to be a great solution on tight job sites where a lot of reach is required. In this case, the Potain Igo T 85 A was a match made in heaven."
The two Potain cranes worked together on the jobsite seamlessly. By combining the large reach of the tower crane with the small footprint of the self-erecting crane, Compass Equipment was able to get "two hooks on the job" to complete the project much more efficiently than if it only had one crane.
