Benjamin Franklin Medal: Tunnel Boring Machine Seminar Part 1

Tunneling History and Tunnel Boring Machine (TBM) Development
Summary of traditional tunneling
The history of mechanical tunnel excavation, concepts and working machines, up to 1950
The first Robbins TBM, 1952
Technical developments and innovations of the past 50 years, including development of:
* Hard rock open machines and disc cutters for rock
* Double shield machines
* Earth pressure balance machines and cutters for working under pressure
* Slurry shields