DESIGN AND BUILD OF A PORTABLE INSTRUMENTATION ELEVATION TOWER

The Western Kentucky University (WKU) Department of Engineering is collaborating with National Park Service Inventory and Monitoring scientists to support National Park Service (NPS) cave environment and ecosystems research. The NPS, together with the United States Geological Survey, provided the funding that has allowed WKU Engineering students, working with WKU faculty and staff and NPS scientists, to design, build, test and deliver two transportable instrumentation lift systems. Each lilt lower has a stationary top platform and a secondary platform capable of continuously raising and lowering instrumentation over extended, unattended periods. NPS-owned instrumentation on the platforms collects air temperature, relative humidity and air velocity data, storing results to NPS-owned devices located on or below the tower. NPS scientists will use the system to gather more accurate data on the quality and movement of air within cave passages and develop predictive models of the environment. The new system will allow measurements as high as 30 feet and make long-term data collection feasible. A variety of design challenges were met by the students working on the project. Portability, flexibility and weight reduction were achieved through a collapsible aluminum base securing the tower, with three-foot PVC sections to build varying tower heights. Stability was accomplished with a tensioning cable system and a gripping mechanism integrated into the base to secure the incomplete lower. Cable spool design and data collection programming achieved positioning accuracy of the moving platform. In addition to satisfying functional needs, the towers were also designed to avoid damage to cave surfaces and meet challenging operating requirements. Tower components are reasonably lightweight and durable, components are shock-resistant, moisture-resistant, easy to dry and clean, and non-corroding. The design modularity facilitates transport by two NPS personnel using duffle bags, and is easy to set LIP and move. The towers support multiple instruments weighing as much as 10 pounds, can be modified to support instruments in varied configurations, and can be repaired in-house by NPS personnel. The towers were designed and tested to assure user friendly, reliable operation. Tower stability, ease of tower construction, accuracy of platform movement, and required battery life issues were solved by the students.