Large-scale Test Facility for Studies of Neutral Temperature/Buckling Detection in Continuous Welded Rail

The UCSD/FRA Large-scale Rail NT/Buckling Testbed
AREMA Committee 4 – Rail Meeting, April 2011


  • Department of Transportation/Federal Railroad Administration
  • Burlington Northern Santa Fe (BNSF) Railway (in-kind)


  • Prof. Chia-Ming Uang, UCSD
  • Volpe National Transportation Center


A unique experimental facility for the study of thermal loads in rails, and for the development of in-situ techniques for the measurement of these thermal loads or, equivalently, the rail Neutral Temperature.


A large-scale Test Facility for the study of thermal stresses and buckling of rails was constructed under FRA funding with in-kind material donation by BNSF. The setup is hosted at UCSD’s Powell Structural Laboratories, the largest laboratories in the country for large-scale structural testing. The test-bed features a 70 ft-long, full rail track with ballast and wood ties, pretensioned to obtain a desired value of NT. Controlled heating of the rail is achieved through a specially designed rail switch heating wire.

This unique facility allows to impose thermal cycles to the rail in a controlled laboratory environment. In addition, the set-up allows to set different levels of Neutral Temperature to the test track. The facility is being primarily used to develop UCSD’s Rail-NT system for the measurement of the rail NT. Other researchers funded by the FRA have also tested their technologies at the UCSD facility.


Selected Publications:

Nucera, C. and Lanza di Scalea, F., “Nondestructive Measurement of Neutral Temperature in Continuous Welded Rails By Nonlinear Ultrasonic Guided Waves,” Journal of the Acoustical Society of America, in press, 2014.

Nucera, C., Phillips, R., Lanza di Scalea, F., Fateh, M. and Carr, G., “RAIL-NT System for the In-situ Measurement of Neutral Temperature in CWR: Results from Laboratory and Field Tests,” Transportation Research Record: Journal of the Transportation Research Board, no. 2374, Washington DC, pp. 154-161, 2013.