Brunel’s Locked Diary, 1827-1829

• This is Isambard Kingdom Brunel’s personal diary which he started writing when he was 21 years old. He wrote in the first entry that he planned to use the diary to record his “feeling habits faults wishes hopes and every thing belonging to the present moment.”
• Brunel did not write in the diary every day; the first entry was written on 11 October 1827 and the last was written on the 6 April 1829. It is only 35 pages long.
• Written in ink, the leather-bound book is known as the “locked diary”. Brunel would have been able to keep his thoughts secret by using the metal clasp and a small key to lock the diary.
• He writes about his work as an assistant engineer on the Thames Tunnel and includes an account of an accident that left him seriously injured. The diary offers an interesting look into Brunel as a person and how he viewed himself.

Near death experience

By the time Isambard Kingdom Brunel started writing his personal diary, he was hard at work as the chief engineer on his father Marc Brunel’s project to build a tunnel under the River Thames. It had been designed to allow people and goods to travel safely under the busy river. It was a difficult and dangerous project with the work taking place just metres below the river.

On the 14 January 1828, the river broke through and started to fill the tunnel up with water. The force of the water caused some of the tunnelling equipment to collapse, briefly trapping Isambard Kingdom Brunel by his leg. When he freed himself, the water carried him along a section of the tunnel. Brunel was able to briefly escape into a less flooded part of the tunnel. He describes in his diary he could hear “the roar of the rushing water in a confined passage and by its velocity rushing past the openings was grand very grand. I cannot compare it to anything -cannon can be nothing to it.”

Unfortunately, the water soon flooded into the part of the tunnel where he had escaped, so Brunel made his way to a nearby shaft and was pulled up to safety by other workers. His time in the water left him with serious injuries, in his diary he wrote “If I had been kept under another minute when knocked down I should not have suffered more and I trust I was tolerably fit to die.” Sadly, six men were killed in the disaster and following his dramatic escape Brunel had to leave the Thames Tunnel project to recover.

Being Brunel

The diary offers a unique chance to learn more about Brunel and how he viewed himself at an early stage of his working life. At the beginning of the diary his mood seems quite upbeat as he describes his busy working day during the construction of the Thames Tunnel. On the 12 October 1827 he writes about waking up at 8am, working above ground on work related to the tunnel until 3pm, then taking charge of the work in the tunnel until 2am. Later, in his diary he mentions waking up even earlier in the day so that he can meet the night shift as they leave the tunnel before he has breakfast.

He also wrote about ideas for future projects. He was already dreaming of bigger and better things and scattered throughout the diary are mentions of “castles in the air”. These were his ideas for future projects, things he dreamt about creating. He writes about bridges, tunnels, engines and a lighthouse but there are no mentions of ships or railways.

However, following the accident in the Thames Tunnel his mood becomes more serious, as work on the tunnel stopped. He also wrote of his disappointment in not being able to buy himself a horse or the best tools due to a lack of money.

There is no indication as to why he suddenly stopped writing in the diary, there were pages left unused. The Locked Diary and many of Brunel’s sketchbooks are part of the University of Bristol’s Brunel Collection, the University has no other Brunel diary like this one, it may be that he never wrote such a personal diary again.

• Find out A Bit about Brunel with this factsheet.
• Test your Brunel knowledge with this quiz.
• Find out more about the Thames Tunnel here.
• Read extracts from the diaries of passengers who travelled on the SS Great Britain.
• Write your own diary entry.
• Find out more about this object and others like it in our online Collection.