In the 1830s, Robert Stephenson developed the London and Birmingham Railway (L&BR) (later known as the West Coast Main Line).

[1] After opposition from several landowners and proprietors in Northampton in July 1832, the House of Lords rejected the original bill to authorise construction of the line.

[1] Problems posed by the quicksand at tunnel level were so severe that abandoning the shaft and restarting work elsewhere was considered.

[1] At the recommendation of George Stephenson, several steam-powered pumps were installed to extract water from the quicksand inside the tunnel.

[1] During this time, multiple attempts were made to construct the tunnel's brick lining using a raft to float men and materials into position.

As a protective measure, the lining's thickness was increased from 18 inches to in excess of two feet and straw was used to deflect and control the ingress of water to prevent wet concrete from being washed away from newly laid bricks.

[1] Author Graeme Bickerdike has speculated that, while their size is excessive in regards to providing airflow, considerable importance was placed on overcoming public perceptions and worries over personal health due to insufficient ventilation, especially in regards to the use of steam locomotives inside lengthy tunnels.

Several newspapers had negatively commented on the issues, and it is likely that Stephenson would have wanted to silence critics and assuage these sentiments by visibly demonstrating how much ventilation was being provided.

[1] On 21 June 1838, resident engineer Charles Lean laid the final brick of the tunnel, marking its completion.

Due to the drastic reduction in rail traffic caused by the COVID-19 pandemic, Network Rail took the rare opportunity to close the tunnel for two weeks in May 2020 in order to carry out major works, including replacing much of the tunnel's drainage system, which had become clogged by heavily limed water seeping through, causing flooding problems, and also replacing much of the track and ballast.