Heavy Lifting News
Case Studies on Innovative Problem Solving
Containment Pit Complicates Placement of 187-Ton Transformers
Heavy Duty Power Slide Ensures Smooth Lateral Move
04/29/2026
By Dave Thorsen
Technical Sales Specialist
Engineered Rigging
The installation of an industrial transformer typically has three characteristics:
- a heavy, high-value load;
- critical job site considerations such as high-voltage overhead wiring or narrow pathways;
- and a time sensitive deadline.
A recent project in Texas, checked all three boxes. The placement of two transformers was needed during the construction of a solar farm’s power substation. Each transformer weighed 375,000 pounds and measured 30’6″ long × 10’7″ wide × 14’8″ tall. The construction site was congested (see aerial photo above), with no room for a traditional crane, and the placement of the transformers had to be completed in just four days.
With forward, backward, and sideways movement, self-propelled modular transporters (SPMTs) could easily move the transformers from the delivery point through the maze of construction materials and groundwork infrastructure. It was the final leg of the journey that was most challenging. To reach its designated pad, each transformer would need to travel 30 feet across a containment pit— a recessed basin designed to capture dielectric fluid in the event of a transformer leak. Once positioned directly over the concrete pad, the transformer would need to be lowered 24 inches to its final position. Advanced Freight Dynamics (AFD), a cargo transporter specializing in over-dimensional freight services, reached out to Engineered Rigging to identify the best solution for this challenging machinery move.
Bridging the Gap
While a skidding system is a natural contender for massive lateral moves, most models cannot transport cargo over an unsupported area—especially a load of this size across a gap of this distance. Fortunately, Engineered Rigging has a solution purpose-built for exactly this type of application: the PS500 Power Slide, a heavy-duty skidding system that supports loads up to 500 tons.
The SPMT would serve as the launch point for the lateral move over the containment pit. Before the 187-ton transformer was moved from the over-the-road (OTR) trailer to the SPMT, AFD placed a section of PS500 track across the top of the SPMT. The transformer was then set upon the SPMT and transported through the construction site to an area alongside the containment pit. Once in position, track was added to extend the pathway from the SPMT to the far edge of the transformer’s concrete foundation. The elevated track was supported by cribbing stacks and load stools, ensuring that the track was level with the SPMT bed.
Powered by a split-flow pump, the PS500’s hydraulic cylinders incrementally pushed the load along the track until it cleared the pit and was positioned directly above the concrete pad (view the video). At this point, ring climbing cylinders were positioned under the four corners of the transformer. The ring climbing cylinders were stroked upward to engage and bear the full weight of the transformer. Once the load was transferred to the ring climbers, the cribbing stacks, load stools and PS500 track were removed, and the ring climbers incrementally lowered the transformer the 24 inches to its final resting position on the concrete pad.
The modular design of the PS500 track and portability of the ring climbing cylinders expedited the dismantling and repositioning of the equipment for the lateral move of the second transformer which enabled AFD’s crew to safely complete the placement of both transformers within the four-day window.
Related Case Studies
- Strand jacks were used to remove and replace 30-ton harps in a power station’s Heat Recovery Steam Generator.
- A hydraulic turntable and Power Slide were paired to install a series of 220-ton power transformers.
- A hydraulic gantry was used in the construction of Chile’s epic hydropower project.
Featured Equipment
PS500 Power Slide
The PS500 Power Slide system used to move the transformers from the SPMT, over the containment pit and into position above the concrete foundation included:
- Four 125-ton slide shoes with integrated load pins (2 × 250-ton slide rails, 500-ton combined capacity)
- Two hydraulic push/pull cylinders for bidirectional load advancement with precise incremental control
- An Enerpac split-flow pump which provided the power for the synchronous cylinder operation and precise load positioning
- 120 feet of modular high-strength track sections
- Load stools and cribbing timbers
Ring Climbing Cylinders
The Holmatro ring climbing cylinders were utilized to incrementally lower each transformer from the elevated skidding system’s track to a concrete pad. AFD purchased two sets of ring climbing cylinders to self-perform the placement of the transformers for this project, with plans to utilize them for future projects, too.
“A lowering operation that took three hours using previous methods now takes just 40 minutes using the ring climbing cylinders. Morale is higher because the team does not have to stack and unstack cribbing lumber during the operation,” explained Steven Lyons, owner of Advanced Freight Dynamics.
