Fifty-Year Highlights of Tunneling Equipment

The advancement in tunnel equipment in the past 50 yr has been dramatized by the reentry and increasing advance rates made by Tunnel Boring Machines (TBM). This paper stresses the advances in other equipment for the tunnel construction process. The means of entry to a tunnel have not changed appreciably; however, the safety of work in a shaft has improved and the rate of moving materials through one has increased. The movement of the waste material from the tunnel's heading has been a major advancement to support the TBM. To achieve greater rates for transporting materials has necessitated more efficient ventilation, power distribution, and haulage systems. Trackage for rail vehicles has had to advance with new arrangements. Other innovations have been made with independent hauling vehicles, belt conveyors, and pipeline systems for moving muck, concrete, and other tunnel materials.