This early 19th-century drawing captures a daredevil moment which could have changed the future course of railway history forever.
It shows 21-year-old Isambard Kingdom Brunel gingerly investigating a breach in the roof of his father Marc’s Thames Tunnel, through which the floodwaters of the dirty river above had poured through, in May 1827.
Had there been another sudden incursion by the Thames, young Brunel could so easily have perished, and we would never have seen the Great Western Railway born.
The watercolour, painted by Marc himself, is contained in a unique album kept in the family for almost 200 years and recently acquired by the Brunel Museum housed in the Thames Tunnel engine house at Rotherhithe and the shaft originally intended as the Grand Entrance Hall.
The museum raised more than £200,000 to buy the album at a recent Bonhams auction, and the purchase was backed by major grant from the National Heritage Memorial Fund.
The 1300ft long Thames Tunnel was considered one of the marvels of its age. It was the first road tunnel in the world to run beneath a navigable river, and ran at a depth of 75ft beneath the river surface at high tide.
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