Project Details: HPS was contracted to fabricate a replacement upper lifting frame. The lift frame has a design lifting/support capacity of 25 ton (50,000 pounds). The new designed upper frame was modified from the original design to minimize the overall height of the combined upper and lower lifting frames. The completed lifting device is used at the Hungry Horse Dam to lift various components.
HPS subcontracted the services of a local contractor to provide mobile crane, welding equipment, tools and field labor as necessary to trial fit the new upper frame to the existing (on site) lower frame. HPS’s project engineer coordinated all subcontractor activities. The connection between the upper and lower frames included four bolted splice plates, these splice plates were predrilled at HPS shop and shipped loose for field installation. The splice plates were bolted to the existing frame and after positioning the upper frame the splice plate holes were match marked to the upper frame. After marking the upper frame holes were drilled and final assembly was completed.
The basic construction was that of a box truss; approximate size was 8 foot wide by 8 foot tall by 20 foot long with an approximate weight of 5400 pounds. The lifting frame included an aluminum grating platform/deck at the top of the structure. The grating platform included a hinged door that was field located and positioned to match the location of an existing ladder.