To build a $3.4-billion underground high-speed railroad into Oslo, Norwegian engineers left their comfort zone of drill-blast rock excavation in favor of tunnel-boring machines. Hard, abrasive rock ...
Workers drill during construction of the Flathead Tunnel in early June, 1968. (Mel Ruder/Hungry Horse News file photo) Conditions inside the Flathead Tunnel during construction. (Mel Ruder/Hungry ...
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