In 1837 Parliament gave permission for the building of a railway between Manchester and Leeds. George Stephenson, the chief engineer, had several problems to overcome on the 51 mile long railway across the Pennines. The most difficult of these was the 1 mile, 1,125 yard long Summit Tunnel.
The Manchester & Leeds line was opened in 1839. Branches were built to Heywood (1841), Oldham (1842) and Halifax (1844) . The three mile Woodhead Tunnel on the line to Sheffield was not finished until 1845. Thirty-two navvies were killed and 140 seriously injured building this tunnel. Edwin Chadwick, later estimated that navvies had more chance being killed building the Woodhead Tunnel (3.0 per cent) than those British soldiers fighting at the Battle of Waterloo (2.11 per cent). In 1848 a line was built to the London & North Western Railway that gave access to York and Hull.