- Waht is it?
- Type of corrugation
- How to limit?
- Corrugation measurement systems
What is it?
Rail corrugation is a phenomenon which takes place as an irregularity that appears on the running surface of rails.
Tangentially, vertically and axially. Wear corrugation is a result of friction on the lower rail, which comes in contact with the train wheel. Excessive corrugation can be identified by the wavelength found on the surface of the rail.
Corrugations are classed in terms of their wavelength, which is the peak to peak distance. Corrugation depth is defined as the distance between a peak and an adjacent valley.
In general there are three band of wavelength:
- Very short: 10 ÷ 30 mm;
- Short: 30 ÷ 100 mm;
- Medium: 100 ÷ 300 mm;
- Long: 300 ÷ 1000 mm;
Types of Corrugation
Rail corrugation takes different forms and has been identified in six different types:
- Heavy Haul
- Light Rail
- Ooted Sleeper
- Contact Fatigue
- Rutting
- Roaring Rails
The way these different types of corrugation are identified is by there wavelenth-fixing and damage mechanisms, the most common wavelength-fixing mechanism is the P2 resonance of a vehicle’s unsprung mass on the track stiffness, this in significant half of the six types of corrugation.
How to Limit?
So how do can it be in someway prevented? Overtime there have been studies of various degrees and means of prevention for all six of the corrugation types have been and are being developed. The excitation of vehicle’s unsprung mass on the track stiffness is the most common wavelength-fixing mechanism.
Corrugation measurement systems
The main way of identifying corrugation is through the measurement of the rail’s profile. This is usually accomplished with high technology lasers paired with high frequency cameras, these pieces of equipment are then attached to a means of transport on the rail tracks allowing therefore an even more precise interpretation of rails condition.
ADTS has solutions for measuring corrugation, both on trolley and on a vehicle. Have a look here!
