Apparatuses, methods, and systems are disclosed to detect and measure cracks in the lining of a container. A typical apparatus includes a scanning device to acquire a cloud of data points by measuring distances from the scanning device to a plurality of points on the surface of lining material and a controller to fit a polygonal mesh and a minimum surface through the cloud of data points, a crack being detected by a portion of the polygonal mesh containing a connected group of polygons that extends past the minimum surface beyond a threshold distance.