The second bore, also referred to as the north tunnel, was undertaken by the Manchester, Sheffield and Lincolnshire Railway. Its construction was speeded up by the decision to construct 25 side access connections from Woodhead 1, in anticipation of a second bore. Although more care was exercised during its construction, in regards to safety conditions, an outbreak of cholera amongst the workforce, in 1849, resulted in 28 deaths. In January 1852, a bulge was discovered in the tunnel wall in the centre section and had to be rebuilt. Later that year, Woodhead 2 was completed.