The name Isambard Kingdom Brunel conjures up thoughts of the Great Western Railway, and other successful engineering projects that are still well regarded today. But on the the In Our Time episode about him Julia Elton (former President of the Newcomen Society for the History of Engineering and Technology), Ben Marsden (University of Aberdeen) and Crosbie Smith (University of Kent) explained that this is not all there was to Brunel, and he wasn't always as successful as his modern reputation suggests. His reputation during his lifetime was mixed - he was an innovator, but also prone to over-reach.
They started the programme by briefly discussing Isambard Kingdom Brunel's father, Marc Isambard Brunel, who was born in France before the French Revolution. He fled to the US as a refugee during the Revolution, and subsequently moved to England. He married Sophia Kingdom, an English woman who he'd met in France during the Revolution. He was a highly successful engineer, and he educated his son to follow in his footsteps.
Isambard Kingdom Brunel was born in England, and his early education was biased towards science, maths & engineering and came from his father. He was then sent to school to get a proper gentleman's education to complement this (Greek, Latin and so on). Afterwards he spent some time abroad before returning to England to work as an engineer with his father. The big project that they were working on was a tunnel under the Thames river. This didn't go as well as was initially hoped, although it was ultimately successful. The ground under the river is not very good for tunnelling through - instead of the clay they hoped for it was gravel. This meant that the progress of tunnelling operations was slow and also dangerous.
Brunel chafed at working in his father's shadow and was very keen to make a name for himself independently. While he was in Bristol convalescing from an accident during work on the Thames Tunnel he got involved in a project to build a bridge there. This was funded by money left in someone's will which had been invested until the interest earnt meant that it was enough to cover the project, and then there was a competition for the design of the bridge. Brunel put his own design in, and won - although the bridge that was built was a slight redesign of his idea, because a Grand Old Man of engineering (whose name I forget :/) said that Brunel's design wouldn't work. I'm not quite clear if this expert was right or not - bucking the conventional wisdom was to be a noticeable Brunel trait, and often he was right. His approach to engineering was a scientific one - to work from first principles, to experiment and to keep meticulous records. This could be a double edged sword, "the way things have always been done" is not necessarily wrong. This project also highlighted another of Brunel's key traits - his showmanship. Despite the project running out of money before the bridge was finished, the grand opening still went ahead as Brunel planned.
As I said at the beginning of this post, the Great Western Railway is what I particularly remember Brunel for, and this was his next big project. Unsurprisingly, his winning bid flung out all the precedents for railway design and started over from scratch - much to Stephenson's disgust. Brunel was aiming for the luxury end of the railway market and so ended up with a design incompatible with other parts of the evolving rail network - his track was a wider guage and his trains were larger than those in the rest of the country. Brunel was initially in charge not only of the engineering of the railway but also of the locomotives, and once again he started over from first principles. Sadly this was not a success, and an inquiry set up to investigate his failures ended by taking control of locomotive design away from him.
Having had overall success in his foray into railway engineering Brunel moved into ship building. This was a natural extension of the Great Western Railway - the idea being you'd travel from London to Bristol by GWR train and thence to the USA by a GWS ship. This project started out as a very nice example of the good in Brunel's approach to engineering. Here conventional wisdom said that if you built a bigger steam ship it would sink, for what are in retrospect silly reasons. Brunel's start from scratch approach meant that he challenged that assumption and discovered that big ships will float. This meant that Brunel's ships could carry more fuel, and so weren't cutting it quite so fine when crossing the Atlantic on a single tank of fuel.
But then he gets carried away and keeps increasing the size of the ships - not all of these larger ones were successful. Although I'm not sure if this was all down to bad design, or if bad luck also played a part - because once he had some bad luck then his mixed reputation would lead to people assuming it was obviously his fault. When his designs and business ventures worked, they worked pretty well, but as soon as something stopped working public confidence in his abilities dropped. And even when things did work there were always niggles and things that might've been better designed differently - like the railway that wasn't compatible with the other networks. His reputation during his lifetime and immediately after his death was decidedly mixed.
One of the experts on the programme, Julia Elton, summed up Brunel's modern reputation as fitting into a narrative we like - the lone heroic figure taking on the establishment and succeeding when they said he'd fail. She thinks that Stephenson was a much better engineer - but Brunel was a better showman. Brunel also kept diaries throughout his life - one set of personal ones, one set of engineering "lab books" - which meant that when his descendants wanted to promote his memory they had ample material to work with.