The Helms Rotors Project was an immediate repair to the large rotors on 3 Helms Units near Fresno, Ca. Repairs included grinding out the cracks and in one case, indexing the 20 7.5-ton poles to new positions on the rim that had not experienced any stress or cracking. The units were then returned to service with a Justification for Continued Operation (JCO) that set a number of start-stop cycles before the rotor must be permanently decommissioned. PG&E also initiated a massive project to replace all three rotors, the successful contractor being Alstom Power, a multi-billion-dollar, world-wide, French-owned consortium.
What makes it interesting?
One Million Pounds. That’s what the rotor for a single Helms 404 Mw Unit weighs. When VoithSiemens notified PG&E that a similar type of unit in Austria had experienced a catastrophic failure, we took notice. The disaster in Austria occurred when a magnetic pole mounting structure failed, stopping the unit in less than one rotation. After evaluating the risk of failure on the Helms Units, PG&E took action. When they inspected the rotors on all three Helms units, some cracking was found that could lead to this same type of failure.
How HCSS Software assisted with this project
The GC Hydro Construction Crew’s implemented HeavyJob during this project to help improve time cards, material, and cost tracking. Using HeavyJob has allowed us to better manage GC crews. Additionally, it has allowed our Project Engineering, Project Management, and Outage Management teams to better manage their projects and get real-time cost.