Gap analysis and overview of emerging technologies

Based on the assessment presented in the previons seetion, and measuring eapabilities shown in section 3.4, a gap analysis has revealed the limitations of existing monitoring technologies and their potential for improvement The analysis has also considered emerging technologies and state-of-the-art techniques employed by systems developers. A surmnary of observations and results is presented below. 

Axle shafts and journals can develop fatigue cracks. Crack initiation can start from a scratch or corrosion. Axle related derailments ate generally associated with the fracture of the axle under a vehicle, usually under conditions of high dynamic loading. These types of failures can be detected in the workshop by NDT inspection, e.g. ultrasound. There is potential for automated technologies dealing with axle defects. 

The current wheel monitoring practices are described in section 20.2, but gaps exist in automatic detection and/or measuring of the following cracked/broken flange, thermal flange crack, cracked/broken/shattered/spread rim, cracked/broken plate, thermal plate crack, hole in plate, loose wheel, wheel gouge, subsurface defect, etc. 

These have been checked with axle load check points and vehicle profile gates. If the vehicle exceeds the limits it has to be excluded fiom traffic. The technologies exist, but there is a gap in their implementation - ideally, wagon faults should be prevented or detected earlier, and skew loading identified at the point of loading. 

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