MT. ST. HELENS VISITOR CENTER,
TRANSMISSION AND LOCATION DISTRIBUTION
AND FIBER-OPTIC COMMUNICATIONS
National Volcanic Monument Visitor Center, Washington
U.S. FOREST SERVICE,
GIFFORD PINCHOT NATIONAL FOREST
Vancouver, Washington
The U.S. Forest Service contracted with TriAxis to provide study, design, and construction services for power and communication systems to serve a visitor center complex just north of Mount St. Helens in southwest Washington. Preliminary design services investigated the cost and reliability of overhead versus underground electric power systems with various configurations and operating voltages. A schematic design document was developed for the selected 25-kV underground power system and the fiber-optic communication system.
The power delivery point includes metering, voltage regulation, system-protection equipment, and step-up transformers (7.2/12.47 to 14.4/24.9 kV). The 30-mile-long transmission line includes three cables and four 300-kVar fixed shunt reactors at specific locations to stabilize voltage swings and reduce system losses. The cable is designed with 345 mils of XLPE/TR insulation (35-kV rating). Splices, elbows, and tap transformers are also rated for 35-kV operation.
The communication system primarily consists of a 4-fiber, single-mode cable without any mid-route amplifiers. TriAxis was responsible for design coordination of the telephone company interconnection, a control building, and the visitor center’s local exchange equipment.
The three power cables and the single fiber-optic cable occupy a 4-conduit duct bank, including 77 underground vaults, located along the shoulder of the new SR 504 highway leading to the visitor center complex. The project includes the crossing of 12 bridges in mountainous terrain. TriAxis also provided preliminary design and geotechnical engineering for the new highway.
TRANSMISSION AND LOCATION DISTRIBUTION
AND FIBER-OPTIC COMMUNICATIONS
National Volcanic Monument Visitor Center, Washington
U.S. FOREST SERVICE,
GIFFORD PINCHOT NATIONAL FOREST
Vancouver, Washington
The U.S. Forest Service contracted with TriAxis to provide study, design, and construction services for power and communication systems to serve a visitor center complex just north of Mount St. Helens in southwest Washington. Preliminary design services investigated the cost and reliability of overhead versus underground electric power systems with various configurations and operating voltages. A schematic design document was developed for the selected 25-kV underground power system and the fiber-optic communication system.
The power delivery point includes metering, voltage regulation, system-protection equipment, and step-up transformers (7.2/12.47 to 14.4/24.9 kV). The 30-mile-long transmission line includes three cables and four 300-kVar fixed shunt reactors at specific locations to stabilize voltage swings and reduce system losses. The cable is designed with 345 mils of XLPE/TR insulation (35-kV rating). Splices, elbows, and tap transformers are also rated for 35-kV operation.
The communication system primarily consists of a 4-fiber, single-mode cable without any mid-route amplifiers. TriAxis was responsible for design coordination of the telephone company interconnection, a control building, and the visitor center’s local exchange equipment.
The three power cables and the single fiber-optic cable occupy a 4-conduit duct bank, including 77 underground vaults, located along the shoulder of the new SR 504 highway leading to the visitor center complex. The project includes the crossing of 12 bridges in mountainous terrain. TriAxis also provided preliminary design and geotechnical engineering for the new highway.
