Today, the glazing portion of two of the World Trade Center towers, One World Trade Center (the Freedom Tower) and Tower Four, is near completion, and among the many companies that have been able to be part of the monumental project, Spider, a division of SafeWorks LLC, and Beta Max Hoist Inc. provided the equipment necessary for Benson Industries, the glazing contractor on the project, to raise the glass panels into their proper places.
Ken Barrett, national salesman with Beta Max, explains the pride they all felt being a part of the project: “It’s not me who originated the saying, but it was through Benson, that they were not just lifting panels, but lifting up the country as well. It has meant a lot to watch that building go up.”
For Benson to get the job done, they used 12 complete Spider swing stages to access the towers’ façades powered by Spider SC1000 traction hoists, and four Beta Max Leo XXL Variable Frequency Drive (VFD) material hoists to lift over 3,000 massive glass panels on each tower and place them into position, respectively.
Precise Swinging
The biggest challenge facing Spider’s team was trying to install scaffolds into the tight space between the curtain wall and louver panels. Marc Frato, district sales representative for Spider, who provided on-site, hands-on training for proper operation of the equipment explains: “The curtain wall was installed on the outside of the building, and then the louvers had to be installed on the inside of the mechanical boards. The result was a couple of feet of louver panels around the top of the building. Trying to rig scaffolds in that tight space was a big challenge.”
So in addition to the standard 20-ft. and 30-ft. modular platforms, Spider used Modulo platforms to reach the structures’ hard-to-reach spaces. “The Modulo platform breaks down into many pieces that can be assembled to make the staging. We used 3- to 5-ft. modular sections, fit one-by-one between the curtain wall and steel structure, and then assembled the plat- form in place. This was the only way to do it and very unique,” says Joe Simone, operations manager for Spider’s New York operation center.
Spider engineers also designed a modular outrigger beam monorail system that supported the platforms and enabled the team to have access all the way around the structures, just inside the perimeter of the curtain wall, in order to access and install the louver panels.
“We engineered and created a continuous beam with various hangers every 10 to 20 ft. along it so they would be able to take the stages and move them from hanger to hanger, leaving them within the confined space once they were assembled,” explains Simone. “The stages didn’t move along the beam, but rather there were various hangers and rigging points throughout the beam to re-locate the rigging point.”
“The equipment and service Spider provided was exceptional, enabling us to flawlessly complete our glass repairs and louver work,” says Eddie Nelson, foreman Tower Four, Benson Industries.
Freedom Hoist System
Four Beta Max Leo XXL VFD material hoists graced each side of the building, respectively, allowing installers to carefully bring the large, delicate glass panels up at a rate of 40 to 80 fpm, and precisely position them for the install.
The Leo XXL’s lift 1,000 lbs. up to 400 ft. and 2,000 lbs. up to 200 ft. with a particularly soft start and stop feature that allows contractors to pick and place delicate materials more efficiently than traditional methods.
“The hoists were placed on all four sides of the tower on parallel I-beams that traveled from corner to corner of the building. This mounting option enabled workers to lift the panels from the floor they were staged on, lift up to a certain point and then trolley them along the face of the building and secure into place,” Barrett explains. “This method saves contractors the time and effort of not having to re-rig the hoists; however, to increase productivity even more on the Freedom Tower, the team brought the panels up with the Beta Max hoist and transferred the payload to a smaller rig to trolley over and put panels into place.”
Barrett explains that by being able to transfer a glass panel that weighed anywhere from 1,400 to 2,000 lbs. to a different trolley at a certain level, they could bring the hook back down on the hoist and bring up another panel while the former was being placed so no time was lost waiting for another panel to arrive after one was positioned.
“The glass was staged on various floors below where it needed to be placed, and the hoist was positioned above the glass,” further explains Frato. “So they would stage the glass, fi t it from above floors, raise it up, and then drop it to the lower floor wherever the next position was—panels weren’t being raised up the entire length of the building.”
The Leo XXL VFD material hoists feature wireless remotes that enable them to be operated anywhere from 500 to 600 ft. away from the hoist, and different mounting options allow the hoist to fit into confined spaces.
However, Barrett says that the biggest advantage of having these hoists on the job was getting to places a tower or Spyder crane cannot. “Our hoist takes the place of, or works together with other cranes to achieve a common goal, complete the project on time or before schedule, safely. In a lot of cases these hoists can do the same work as a tower crane at a fraction of the cost—considering the cost to set up the crane, break it down, and pay for a certified operator. Additionally, Benson could work independently on other subcontractors on the building. When you’re using a crane, there’s a lot of coordination that has to take place with the subcontractors. It’s another reason they like the parallel I-beam set-up to get the panels into place,” says Barrett.
Power Required
Another consideration for the Spider and Beta Max teams was New York’s power requirements for jobsites, especially during the summer months when most of the work was performed.
“New York requires 208-voltage on a jobsite and most equipment is designed for 220-voltage,” explains Frato. “The SC1000 traction hoists are designed with that in mind and are capable of going down to 170 volts. This solved the issues Benson was having. They had a lower voltage to start with and the use of long lengths of power cord would cause additional loss of power.
Barrett explains how the VFD hoist is uniquely suited to tackle this situation as well: “The Leo XXL VFD makes it convenient for contractors on the site because it runs on 208-volt single or three-phase power. The electronics for the VFD allows it to automatically detect the phase of power on the building and only draw the power it needs according to load capacity.”
Proud to be a Part
“We’re proud to have our equipment on such a historic building; this is one of the biggest icons in the United States and I know that Marc and Joe feel the same way,” concludes Bart Pair, director of sales and marketing, Beta Max.
“Spider takes pride in being an integral part of these high- profile projects,” says John Sotiroff, vice president Spider Sales and Distribution. “As the nation watched the progress of the iconic World Trade Center towers, Spider swelled with patriotism and remains focused on keeping these and other quality contractors around the country safe at extreme heights.”
Lift & Access is part of the Catalyst Communications Network publication family.
