The sunk tower used as a shaft to access the building site.

Sometimes random is a wonderful thing. I’m not one for planning days out for hours only to be disappointed when they go wrong so as I age, I often find myself picking outings more or less randomly. I have to say eenie meenie miney moeing the Brunel Walk out of the fantastic program offered by the website London Walks ended up as a great decision as I now know about one of the most fascinating engineering stories from the Victorian Era.

Imagine London at the turn of the 19^th century. Millions of tons of goods arrive through the miles upon miles of dockland stretching along the tidal Thames that make up its port. Tobacco, rice, brandy, whale oil, cloths and coal are delivered to London from all over the world. It is simply the busiest port in the world. Over 1500 ships can moor simultaneously and not only does this create a vast amount of wealth but also congestion that put the M25 to shame. Traffic jams at the time routinely last days and up to a whole week!

In a bid to alleviate traffic in London it was decided a tunnel would be built under the Thames from Rotherhithe to Wapping. A group of Cornish miners had already failed the project in 1805 due to the conditions of the ground and that’s when the Anglo-French engineer Marc Brunel stepped in. In 1825, after developing a revolutionary tunneling method and getting the patronage of the Duke of Wellington, he and his son started on the most ambitious and colossal project of the time, soon called the 8^th marvel of the world.

Marc Brunel’s brilliant idea for digging out under the Thames without being flooded was to first build a hollow brick tower that sunk into the soft ground, hence providing a shaft from where to start digging. If this isn’t problem solving I don’t know what is. The tunnel was then dug from a shield where miners in a kind of multilevel box removed 4 inches a day, until completion in 1843.

The story is too long to tell. It is truly a story where resilience triumphs over a gazillion of obstacles thrown in its path. The Brunel museum in Rotherhithe tells it all simply and you can still visit what remains of the shaft. Let me just bullet point some of the striking facts about this gigantic enterprise.

-When Marc Brunel became ill, the most enormous building site in the world was then supervised by his son Isambard Kingdom Brunel who was, wait for it, 19! Now I’m happy when my students get to class on time at 18 so we are really talking about another era here!

-The tunnel started to lose money straight away and in order to recover it and fund more inches it soon became the attraction of the day. Visitors could get down and breathe the foul air under the Thames. It later sheltered a fun fair, stalls, dinners, balls and memorabilia was sold. If it was today no doubt you’d get a T.shirt with “Keep calm and carry on digging” printed on it. Some of the memorabilia can still be seen in the museum.

-Miners and engineers kept getting ailments such as inflammation of the eyes, skin rashes and feeling sick. The stench was so bad that some had to get out after two hours.

-The tunnel was flooded on several occasions and 6 workers lost their lives because of it. Isambard himself escaped one flood by the skin of his teeth.

-The tunnel is 11 m wide by 6 m high and 396 m long. It is now still in use, hosting part of the London Overground, which is an achievement for a tunnel running 23m below the surface!

-Built by a French dynasty, it served the French extremely well a century after its construction when it proved the perfect solution to move troops fast and safely during WW2 in order to get them on the boats towards the coasts of France.

I am sure to have a thought for Marc and Isambard Brunel each time I use the much bigger tunnel under the Channel. After all it was built with similar methods and if this first tunnel had never been built I might still be taking the boat to get to France!

The Mayflower pub is located 10m from the Brunel Museum, was used by sailors from 1600 onwards and you can then walk back to central London via the docks.