Question: How long is the tunnel which Erstfeld railway station sits at the foot of the ramp to?
Sentence (from "Blea Moor Tunnel"): Built by the Midland Railway, it took more than four years to complete, passes some 500 feet below the moor after which it was named, and was built with the aid of seven separate construction shafts sunk from the moor above.
Relevant evidence: No