ALL Relies on Two Liebherr Cranes to Set Pedestrian Bridge
June 30, 2021 – Constructing a three-span pedestrian and bicycle bridge over the third-busiest railroad tracks in the United States can be a challenge, especially when the railway sees an estimated 100 trains per day.
Success on such a project requires working closely with the railroad to get the work-clearance time to set spans. And it’s likely to be scheduled in extremely brief, single-hour increments.
That was the case when a new hiking and biking bridge was constructed in Cleveland’s Wendy Park as part of an expansion of the Ohio & Erie Canal Towpath Trail.
The 100-mi. path connects Cleveland to Cuyahoga Valley National Park and cities to its south.
The ALL Family of Companies provided several pieces of equipment for the job, including aerial lifts, a forklift, and the two cranes used to set bridge spans and the final arch that topped off the structure.
The cranes were a 495-USt capacity Liebherr LTM 1450-8.1 and a 275-USt capacity Liebherr LTM 1250-6.1.
The two cranes often worked separately in setting 124’8” spans that weighed 42.4 USt. But, for one critical window, they worked together to help set the two halves of the arch and hold them in place so Youngstown Bridge’s ironworkers could splice them in mid air.
Plans for the lift were submitted months in advance to Norfolk Southern Railway, owner of the tracks. ALL specified the cranes.
Once the plan was submitted, no changes could be made to the lift. And, when the approved work time finally came, the team on the ground would likely have just one hour to place the arch.
That is usually the maximum amount of time a railway can halt train traffic for lifting work.
In the days leading up to lift day, Dan Lewis, project supervisor for Youngstown Bridge, had his team perform several pre-lift tests to make sure they would be ready to make the most of their time.
“This gave our ironworkers the opportunity to fine-tune the rigging of each arch section, incorporating the actual crane configurations that would be used on lift day,” said Lewis. “This was important, given the time constraints. The team could know, well before the lift, that the two arches would be within a degree or two of each other at the splice point.”
For these practice runs, Lewis also assigned zones on the arch to each of his ironworkers so they would know exactly where to focus their efforts and what tasks to perform during the splicing.
The railway window was scheduled for mid-April then was suddenly moved up by three days. Lewis praised the flexibility of ALL Crane, noting how quickly they were able, on short notice, to mobilize the 275-USt capacity LTM 1250-6.1 to have it assembled and ready for the lift. When the lifting hour finally arrived, nearly eight months of planning came down to 60 min. The LTM 1450-8.1 was configured with 157’6” main boom at a 49’2” radius and the maximum of 147.4 USt of counterweight.
The LTM 1250-6.1 had 131’3” of main boom at a 32’10” radius.
In the days preceding, both cranes had already been quite busy. The two 124’8” bridge spans were set on their respective abutments and temporary structures toward the middle, as well as a 246’ center span resting on the temporary structures.
By installing the arch, which would assume the bulk of structural support for the entire bridge, the temporary structures below could be removed, and the bridge would essentially be complete.
With the clock running, crane operators held each arch piece in position as a dozen ironworkers, six in mobile elevating work platforms and six on the ground, swarmed the area to install scores of bolts at critical splice points. There was a minimum number of bolts that had to be installed for the structure to support its own weight, and that became a crucial milestone. It meant that, should the work window start to close, the bridge would be stable enough to stand on its own. If the milestone weren’t met, ironworkers would have to reverse course and disassemble the arch so they could try again another day, something no one wanted.
When the threshold was reached at the 35-min. mark, everyone was relieved. Just 23 min. later, at minute 58, the work was completed, and the new bridge was a reality.