A blue plaque has been unveiled 40 metres underground on a wall in HS2’s Euston tunnel between Old Oak Common and Euston, which marks the last resting place of Sir Marc Brunel and his son Isambard Brunel.

The tunnel is being constructed using tunnel boring machines, and passes underneath Kensal Green Cemetery, which is where Sir Marc and his son Isambard Kingdom Brunel are buried, and was the first of seven cemeteries established outside of central London between 1833 and 1841.

Attending the unveiling were Mark Wild, HS2 Ltd Chief Executive, Katherine McAlpine, Director of the Brunel Museum, and engineers from the tunnel contractors, Skanska Costain STRABAG.

Sir Marc Brunel will be remembered for being inspired by the boring mechanism of a shipworm when, in 1818, he invented the rectangular tunnelling shield. In 1825, it was used to excavate the world’s first underwater tunnel underneath the River Thames in London. Brunel’s principle of the tunnelling shield is still being used over 200 years later, by HS2 with tunnel boring machines fitted with cutter discs.

Sir Marc’s son, Isambard Kingdom Brunel, continued his father’s revolutionary tunnelling techniques when he built the Box Tunnel between Chippenham and Bath for the Great Western Railway, which, at the time, was the World’s longest railway tunnel. Critics considered it to be an impossible and dangerous task; it is considered one of Brunel’s most celebrated structures.

Isambard Kingdom Brunel is widely regarded as one of the most celebrated civil engineers of all time. He was a chief engineer of the Great Western Railway, where he collaborated on the design and construction of Paddington Station, and designed the Clifton Suspension Bridge in Bristol.

During the construction of tunnels for HS2 between London and the West Midlands, extensive monitoring is being continuously undertaken before, during and after tunnelling. In places suspected to be sensitive historic sites, detailed assessments and specialist works ensure the protection of vulnerable heritage assets. Such monitoring took place underneath Kensal Green Cemetery to ensure construction took place safely, conscientiously and with respect.

“Modern tunnelling of the scale of HS2 would not have been possible without Marc Brunel. His tunnelling shield which he patented in 1818, made way for the Tunnel Boring Machines of today. 200 years ago, the father and son team embarked on an audacious project to dig the world’s first tunnel under a navigable river, laying the foundations for huge projects like this.I am delighted we are able to mark this milestone of HS2 travelling underneath the final resting place of Marc Brunel and Isambard Kingdom Brunel, as a testament to their ingenuity and perseverance.”

Katherine McAlpine, Director of the Brunel Museum in London