Question: How many miles long is this major railway link between London and Edinburgh, in which The Swinton-Doncaster line is a short railway between Swinton Junction and Doncaster South Yorkshire?
Sentence (from "Swinton–Doncaster line"): The line comprises the former North Midland Railway's "Swinton curve" between Swinton and Mexborough and the east end of the former South Yorkshire Railway Blackburn Valley line, between Mexborough and Doncaster.
Relevant evidence: No