Alternatives such as elevated concrete tubes with partial vacuums have been proposed to reduce costs.

Terminal 2E, featuring a stunning, airy elliptical concrete tube about 100 feet wide and 1,000 feet long, was his last project before he retired.

A 500-foot portion of the tracks will be wrapped in a steel and concrete tube to reduce train noise.

Porous materials like uncoated concrete tubes cannot be used.

To prevent another flood, the city enclosed the Mill Creek in a concrete tube running underneath the city.

Traffic had slowed, and they were creeping along an endless concrete tube, its interior lit a sickly amber.

At its Manhattan terminus, the tunnel is made up of two concrete tubes side-by-side in the earth, each one 19 and a half feet across.

The tower is constructed from three concrete tubes which are assembled together in the form of a tripod.

The pools in this work are at the top of concrete tubes imbedded in the ground.

At least the slimy surface of the concrete tube would make the job easier.