Refuge Update – July/August 2008, Volume 5, Number 3

Table of Contents: Protecting Borders and Wildlife, page 4 Scientists Puzzle over Great Lakes Die-Offs, page 6 Focus on. . . Strategic Habitat Conservation, pages 8-17 People Who Keep the Wheels Turning, page 22

Measurement, Simulation, and Analysis of the Mechanical Response of Railroad Track

Increased railroad traffic volumes, speeds, and axle loads have created a need to better measure track quality. Previous research has indicated that the vertical track deflection provides a meaningful indicator of track integrity. The measured deflection can be related to the bending stresses in the rail as well as characterize the mechanical response of the track. This investigation summarizes the simulation, analysis and development of a measurement system at the University of Nebraska (UNL) to measure vertical track deflection in real-time from a car moving at revenue speeds. The UNL system operates continuously over long distances and in revenue service. Using a camera and two line lasers, the system establishes three points of the rail shape beneath the loaded wheels and over a distance of 10 ft. The resulting rail shape can then be related to the actual bending stress in the rail and estimate the track support through beam theory. Finite element simulations are used to characterize the track response as related to the UNL measurement system. The results of field tests using bondable resistance strain gages illustrate the system’s capability of approximating the actual rail bending stresses under load.

NPCA EDUCATION COMMITTEE

The major thrust of the Education Committee results from the rather urgent need to implement interesting programs in which supervisors may train for examination and certification under the qualifications of the pesticide act. While it is not easy at this time to determine what certification is going to be, what supervisors are going to be involved, what kind of examination they are going to have to take, and how the state is going to interpret all of this, we therefore cannot be specific. The wheels are grinding away, and as you know, the timetable is winding down; and we may be faced with a rather short period of time to get these people qualified. Our industry hopes that we will have the training to offer and that all supervisors from around the country have the opportunity to prepare, take the examination, and be certified.