CWLP’s Dallman 4 – power-generating unit
The city of Springfield’s public utility, City Water, Light & Power (CWLP), constructed a new 200-megawatt power generation unit – called Dallman 4 – to replace an older 76-megawatt coal-fired unit. With the installation of this unit, CWLP became one of the most environmentally friendly primarily coal-fired electric utilities in the nation, earning national accolades for its efforts.
CWLP selected Hanson to provide construction management and construction observation services for Dallman 4. Additionally, during construction of the Dallman 4 unit, Hanson provided on-call services as needed to respond to geotechnical, environmental, stormwater management, waste management, code compliance and land surveying issues.
Hanson’s construction management services included having personnel on-site during construction and start-up and providing documentation using specially developed forms for this project.
One interesting aspect of the project was that Hanson personnel, working in shifts with CWLP employees, provided on-site construction coverage 24 hours a day, seven days a week, during the 28-day continuous concrete construction of the new 440-foot-tall Dallman 4 chimney.
Construction observation activities included observing the installation of the following items:
- plant’s grounding, bonding and grid system
- lightning protection systems for the cooling tower, chimney and generation buildings
- 600 drilled pier foundation elements to support facility components
- turbine and generator
- GSU, MAT and RAT
- isolated and non-isolated electrical duct
- 6,900 volt, 480 volt and DCS cable
- underground fire loop piping and dust suppression piping
- plant cooling circulation water system
- 138,000 volt inner-connected over-head facilities to high voltage switch yard
- underground duct-banks and electrical vaults
- electrical distribution systems including cable tray installation, cabling and 6900-volt and 480-volt SWGR
- fire protection system
Hanson also observed the construction of the following items:
- sub-grade and above-grade concrete structures
- buildings for the boiler, turbine and air quality control system (scrubber)
- coal reclaim facility