You may or may not have heard of Sarah Guppy, but this history-making woman achieved amazing things in Bristol back in 1811. Whilst women of the time were expected to be carrying out domestic duties, Sarah Guppy was inventing new products and creating unique designs, including a design for a bridge to cross the River Avon.
Her inventions and patents included a new way of protecting ships from barnacles, a bed with built-in exercise equipment and a device to boil an egg from the steam of a kettle. Brunch would definitely be a lot quicker to make with that egg-steaming device that’s for sure. With it being the Georgian era, these all had to be registered by her husband in the name of ‘the Guppy family’.
In 1811, Sarah Guppy came up with probably one of her proudest and most ground breaking designs of her time. She patented “a new mode of constructing and erecting bridges and railroads without arches or sterlings whereby the danger of being washed away by floods is avoided”. At the time, there was only one bridge to cross the River Avon, which was the medieval Bristol Bridge in the heart of the city. The bridge Guppy patented was site-specific to the low-level River Avon crossing at Hotwells, upstream of the Avon Gorge.
According to Women Engineer’s History: “The Avon has one of the highest tidal ranges in the world and it was impossible to found piers or protective starlings in the centre of the narrow channel. Any pier would have been in constant danger of collapse from the powerful tidal movement of the river.
“Furthermore, the river runs between exceptionally high mud banks, presenting challenging foundation problems. These conditions necessitated a single span of between 200ft and 300ft, greater than was achievable by arched bridges. In the context of 1811, Guppy’s patent outlines a reasonable way of dealing with such constraints.”
Sarah Guppy’s patent did not include any drawings of the bridge and no detailed information as to how the bridge was actually to be built. However, from her description, she envisaged a pair of chains over which would be laid timber planks to form the deck. The chains would be anchored to some kind of timber framing protected by piles, though there are no specific details of how she intended to achieve this.
There has been a lot of speculation as to whether Sarah Guppy contributed to Brunel’s design of Clifton Suspension Bridge. Although the finished design is not the same as the one described by Guppy, some argue her design had some influence. Sarah Guppy patented a way of piling foundations to create a new type of suspension bridge, which some say provided the blueprint for both Brunel’s Clifton Suspension Bridge and Thomas Telford’s Menai Bridge in Anglesey.
Sarah Guppy met Brunel in 1829 when he visited Bristol for the competition of designing the Clifton Suspension Bridge, and also used her influence in society to help promote the bridge and the Great Western Railway. It wasn’t until 2017, however, that Guppy was recognised for her contribution to the designing of Clifton Suspension Bridge when she was added to the Oxford Dictionary of National Biography.
According to Clifton Suspension Bridge, “She deserves to be considered in a wider context and the extravagant and incorrect claims made for her bridge have overshadowed her many genuine achievements and the place she managed to win for herself against all the odds in an all-male world.”