Board of Water Supply. City Water Tunnel No. 2. Patrick McGovern, Inc., contractor. Grouting of the concrete tunnel lining in progress. The equipment is rigged up on flat cars being moved into position by a storage battery locomotive. Generally four such cars are used, holding, respectively, cement and sand, a grout mixing machine, a pump, and a timber working platform for drilling out and making connections to the grout pipes. In the left foreground is the grout mixing machine, followed by the pump and working platform cars. The grout hose leading from the pump is shown connected to one of the arch grout pipes. November 20, 1931.