St Louis, Missouri-based heavy rigging and haulage specialist HWP Rigging used a Hydra-Slide HT500 system to skid a failed transformer out of an electric generating facility and replace it with a new one during an emergency callout recently.
One of the Missouri plant’s four generators was out of service due to the failing step-up transformer, which increases the voltage of electricity that is generated by the turbine so it can be transmitted through the grid to homes and businesses.
The 500t capacity heavy track system skidded the transformer 120 ft. clear of the existing foundation before a replacement was unloaded from a self-propelled modular transporter (SPMT) and slid into position, again utilizing the HT500. Both transformers weighed approximately 400 tons; the replacement unit was designed to be as close a match to the original as possible.
Steve Hentrich, project engineer, HWP Rigging, said: “We started removal of the failed transformer on a Friday afternoon and worked around the clock until the replacement transformer was set in its place, working five consecutive shifts until Sunday morning. We spent two to three days on the front and back end mobilizing equipment and assembling / disassembling the modular trailer onsite. The work was completed ahead of schedule and without incident.”
HWP owns four HT500 skidding systems, from Canada-based manufacturer Hydra-Slide, which are typically employed in the power distribution sector. They are one of the most cost-effective and accurate methods for moving, loading or unloading such transformers, in addition to generators, compressors, pressure vessels and other machines where a rigid, load carrying track is required.
HWP is well-known in the heavy rigging and haulage sector for utilizing a custom 500-ton capacity turntable, also manufactured by Hydra-Slide. The turntable, designed for rotating heavy and oversized loads, was first used to lift and remove an overhead bridge crane in a foundry, hold it for a short time, and place it back on its foundations in one continuous motion.
Hentrich said: “Typically cranes are put in place before completion of a new building so that it is possible to set the equipment through the roof of the building with a mobile crane. In this case the work had to be done with the building roof and walls intact, which eliminated the possibility of using conventional construction equipment to do the work.”
HWP used a set of hydraulic gantries and the turntable to lift the 75-ton load and rotate it almost 90 degrees to clear its foundations before lowering it to the ground. After a short time the crane was again lifted, turned back to its original orientation using the turntable, and set in place on the foundations.
The turntable measures 10 ft. in diameter and weighs approximately 5 tons. Hentrich explained that the parameters were selected for ease of transportation and handling. It can be placed on a road truck and hauled to a jobsite as needed, he said. It is light enough to be handled with a rough terrain construction forklift, which are commonly found on jobsites. The turntable is sufficient to handle most large distribution power transformers.
Hentrich said: “In recent years we have observed an increasing demand for transportation and rigging of new power distribution and generation equipment to replace our ageing infrastructure. This equipment includes large power distribution transformers, steam turbines, generators and industrial electric motors. In some cases new equipment is installed as part of a scheduled maintenance project. Other times failed or failing equipment must be quickly replaced in order to restore power to homes and businesses.”
He added: “The Hydra-Slide skidding systems and turntable are an integral part of many of these projects. Their products can be utilized to efficiently and safely move large loads in confined spaces and allow for precise placement and alignment of heavy loads. We will continue to collaborate with Don [Mahnke, president] and Janine [Smith, vice president] to find innovative lifting and rigging solutions that make our work safer, faster and more efficient.”