Rail workers withstood track temperatures of over 40 degrees celsius to complete a nine-day programme of improvements on the West Coast Main Line.
Four junctions were replaced and three miles of track re-laid between Warrington and Preston, allowing Network Rail to lift a long-standing 50mph speed restriction along the line.
In total, 720 track workers helped deliver the project.
Network Rail estimated that over the closure the team consumed 900 barrels of water and 3,000 bottles of sun cream.
Martin Frobisher, area director for Network Rail, said: “I was in the cab of the first test train over the line this morning and I’m pleased that under some tough weather conditions we’ve been able to deliver on time, this vital improvement which will make journeys on the west coast main line more reliable and punctual.”