In recent years, Lachel tunnel inspection teams have evaluated pre-Civil War railroad tunnels, National Park highway tunnels, live sewer tunnels, old mine drifts, water conveyance tunnels, subway tunnels, and even an underground unlined chimney. The company has developed the techniques and experience to inspect these tunnels quickly, safely and efficiently with a minimum of operational disturbance. Based on the inspections, the structural stability, hydraulic and hydrologic, geotechnical, and maintenance aspects of the tunnels can be evaluated and realistic recommendations developed.

Lachel has prepared full rehabilitation designs including construction cost estimates for successful rehabilitation of numerous tunnels. Several rehabilitations went beyond a direct repair, requiring modification of the tunnel for an alternate use and/or enlarging the existing tunnel opening. Lachel is also available during the rehabilitation construction phase to ensure that the design objectives are being met and to handle rehabilitation issues as they arise.