Heavy Lifting News
Case Studies on Innovative Problem Solving
Ring Climbing Cylinders Rise to the Occasion in Bridge Launchings
02/24/2025
By Greg Bogdanski
Sales & Support
Engineered Rigging
Barnard Construction Company of Bozeman, Montana is an industry leader in projects ranging from hydropower to civil construction known for its innovative and collaborative style. The firm approached Engineered Rigging (ER) in search of a hydraulic solution for the lowering of two temporary bridges after they were separately launched into position. Our team of heavy lifting experts were up for the challenge.
Temporary truss bridges are fast becoming standard in civil and utility projects as they enable traffic to continue to flow over a water way or valley while a new bridge is being constructed. Acrow of Parsippany, NJ manufacturers modular steel bridging that is versatile, cost effective and easy to assemble onsite. Barnard planned to install a 220-foot temporary bridge by Acrow at projects in Texas and Tennessee.
Incremental bridge launching, a construction process which originated in Europe in the 1960s, is a method of bridge building in which the structure is built in a launch bay or back span and the bridge segments are pushed, often using Roller Chain Skates (rollers). After a bridge is launched, the rollers need to be removed, and the bridge deck is then lowered onto the bridge bearings, a structural component that provides a permanent resting surface between the bridge piers and the bridge deck. Our team was familiar with incremental bridge launching as Engineered Rigging provided the rental of Strand Jacks and Hilman Rollers for the construction of Kentucky’s tallest bridge.
For the lowering of the Barnard bridge decks, the original project plan called for jacking and fleeting using two large cribbing stacks and low-height cylinders. However, a jack and crib operation of this nature requires a lot of manual handling of heavy timbers. Recognizing that there might be room for improvement, Barnard asked Engineered Rigging if there was an alternative solution.
Lifting or lowering a bridge deck is no small feat. It requires several considerations, including the weight of the bridge, the distance to be raised or lowered, the span of the bridge and factoring in the flexibility and thereby the accuracy required for the lift.
The Texas bridge had a jacking load of roughly 143 kips per corner totaling just over 286 tons, and its bridge deck needed to be incrementally lowered approximately 38 inches. The bridge in Tennessee had a total jacking weight of 142 tons.
Knowing that a standard hydraulic cylinder would not meet the distance requirement, the ER team introduced the Holmatro Ring Climbing Cylinders to the discussion. These innovative cylinders have a maximum lift height of 35.91” and could likely replace the cribbing stack. We knew that if we staged the Ring Climbing Cylinders higher on Azobe Cribbing Timbers and teamed them with a Low-Height Cylinder to provide an opportunity to reset the Holmatro cylinders, we could reach the maximum lifted height and lower the load efficiently all the way to the bearing.
Our engineering team developed a computer model to identify a step-by-step process to safely lower the bridges using fewer steps and less equipment than the original project plan. Seeing is believing! The simulation gave the Barnard team the comfort to switch to the more efficient process using hydraulic cylinders.
First up was the Texas project. It was decided that the bridge would be lowered one end at a time. Augmenting the ring climbers was an Enerpac Split-Flow Pump. The pump featured remote control of multiple lifting points and ensured precise synchronized lifting and lowering regardless of the forces put upon the cylinders. The combination of the tool rentals provided by Engineered Rigging optimized safety and ease of operation. As a result, the Barnard team was able to use the equipment successfully without on-site support. The operators required only minimal assistance via phone from the ER technical support team.
The bridge deck at the Tennessee project was lowered in the same manner, using the same equipment except the Low-Height Hydraulic Cylinder was for a lower load capacity given the lighter weight of the bridge.
“As an innovator in our field, Barnard welcomes the opportunity to step outside of the box to realize efficiencies. Engineered Rigging provided a solution that saved time while maintaining Barnard’s commitment to quality and safety. It was a win-win for us and our client,” said Will Stevenson, Project Engineer with Barnard Construction.
“We love it when a plan comes together. By renting equipment, civil construction contractors can address unique project challenges and fill gaps in their equipment inventory. We appreciate Barnard entrusting Engineered Rigging as its rental partner,” stated Mike Beres, Vice President of ER.
New technologies in heavy lifting and specialized transport equipment often push boundaries and create new levels of efficiency. That is the case with Holmatro’s Ring Climbing Cylinders. If you’d like to learn more about this innovative hydraulic lifting solution, please contact our heavy lifting experts at sales@engineeredrigginggroup.com or 844.474.4448.
