Also, there was something that looked like another vertical shaft of some kind.

Titus wasn't sure he was going to make it to the vertical shaft.

"No wonder they gave up the vertical shaft down by the cabin."

The light we had seen issued from a vertical shaft.

"We have to concentrate our attention now on the other vertical shafts."

A tremendous vertical shaft had been cut clean through it.

The new vertical shaft will allow digging to begin below the water table.

He paused now at a window that faced on to a deep vertical shaft.

Now she is plunging straight down the face of a vertical shaft.

It was a vertical shaft in the rock, like a natural chimney.