Automated crack classification for the CERN underground tunnel infrastructure using deep learning

•A Deep learning training comparison was conducted to specify optimal technique.•A Transfer learning model is used to create a Crack detection CNN for tunnel lining.•A Directional crack classification CNN was created using Transfer Learning.•The sliding window technique is used in conjunction with CNN’s to test the Models.•The CNNs were developed using Images from the Tunnel lining at CERN.