Not far from where I grew up, in the market town of Maidenhead, there is a railway bridge spanning the River Thames. The bridge was completed in 1838 and consists of just two arches which meet at a small island in the middle of the stream. The best view of the rail bridge is afforded by the nearby A4 road bridge, which itself requires six arches to allow pedestrians and traffic to cross the same span.

At the time of opening, the two arches of Maidenhead Railway Bridge were the widest but flattest brick arches in the world (here). Even by today’s standards, the bridge looks unusual; at the time it was simply sensational. Indeed, the bridge looked so incongruous that the Director of the Great Western Railway instructed that the wooden scaffolding used in its construction be left in place to support the bridge. The scaffolding was later washed away in a flood. The bridge held, and continues to do so; the architect was vindicated. That architect, of course, was Isambard Kingdom Brunel.

Brunel Universally

It is hard to overstate the impact Brunel had on 19^th Century Britain. Among many other projects, Brunel masterminded the construction of the Great Western Railway connecting London and Bristol, including designing Maidenhead Railway Bridge.  Brunel designed and oversaw the construction of the SS Great Western.  At the time this was the World’s longest ship and became the second ship ever to cross the Atlantic using steam power. Brunel was responsible for the first tunnel under the river Thames connecting Rotherhithe and Wapping. The list of Brunel’s engineering superlatives is so extensive that a 2002 poll for the BBC named Brunel the second Greatest Briton of all time, beaten only by Winston Churchill (here).

But perhaps Brunel’s most iconic project is the breath-taking Clifton Suspension Bridge which spans the river Avon near Bristol.  Many consider the bridge to be his finest work, but is the Bridge his work at all?

The Mother of Invention

Brunel collaborated with many other engineers and architects during his career. His own father, Marc Brunel, helped him with the Thames Tunnel. However, one of his most curious collaborators was a woman named Sarah Guppy.

Born in 1770 to a wealthy family of sugar merchants, Sarah was given an excellent education and had a keen interest in engineering. Even so, female engineers at the time were few and far between so it must have been a struggle for her to break into the world of engineering. On her road to becoming an engineer, it is reported that Guppy borrowed more books from Bristol Library than any previous female borrower (here).

Much like Brunel, Guppy’s interests were many and varied. She developed a device to prevent barnacles from growing on the hulls of ships, earning her a £40,000 contract with the Royal Navy. She invented a bedstead which doubled up as an exercise machine, with under-bed drawers which could be used as steps. She also developed a system for boiling eggs in a coffee urn, with the added ability to keep toast warm (here).

Guppy also had a keen interest in intellectual property and was responsible for at least 10 patents in her lifetime. However, since women were not entitled to own property, these patents were held in her husband’s name. The Industrial Revolution may have been transforming British life at an unprecedented rate, but the treatment of women was very much stuck in the Dark Ages.

Suspend Your Disbelief

Patents are where the controversy around Sarah Guppy begins. In 1811, Guppy became the first woman to be listed as an inventor on a patent for a bridge. Her patent, “erecting and constructing bridges and rail-roads without arches or sterlings, whereby the danger of being washed away by floods is avoided” envisaged a pair of chains over which would be laid timber planks to form a deck. The chains would be anchored to a timber framing protected by piles (here). We know Guppy gave this patent to her long time collaborator, Brunel.

This is where the story becomes less clear. Some Guppy proponents, including the Bristol Post (here) have linked her patent directly to the Clifton Suspension Bridge, arguing that Guppy should be credited as the true architect of the engineering marvel. Several sources suggest that Guppy did not seek recognition for the design as it was not becoming for a woman to be too boastful (here).

Others, including the Institute of Civil Engineering (here) have pointed to the numerous differences between Guppy’s design and the actual Bridge, concluding that Guppy’s 1811 patent had no influence on Brunel’s final design. Indeed, there is a rather unpleasant suggestion that Guppy herself promoted the myth that her patent was the basis for the Suspension Bridge despite knowing this was not the case.

The truth is likely somewhere in the middle. While the patent itself may not have been used by Brunel, there is evidence that Guppy and Brunel worked together on a new way of piling foundations for the bridge.

Regardless of where the truth lies, Guppy’s impressive career continued. She worked with Brunel on many other projects including the SS Great Western and its successor the SS Great Britain. Many also believe that the principles Guppy established in her patent were later used in Thomas Telford’s Menai Bridge between Anglesey and mainland Wales.

But Guppy’s legacy extends beyond bridges and ships. She was also a fervent feminist and philanthropist, founding a number of charities promoting the education of women. She used her platform to publish pamphlets on a wide range of topics including roads, animal welfare, public health, education, agriculture and horticulture (here).

Bridging the Gap

We like to think we live in more enlightened times where men and women can invent on equal terms. But the numbers tell a different story.

Back in 2018, Gillian described (here) how the share of International Patent Applications with one or more female inventors was 30.5% based on evidence from a 2016 report. The UK was bringing the average down with just 22% of UK originating International Patent Applications including a female inventor. Last year, Carolyn reported (here) that the figures had not shifted much in 5 years. In 2021 the percentage of International Applications with at least one female inventor had risen, to just 33.3%. Carolyn also reported that female inventors are more likely to have their patent applications refused than their male counterparts. Women may now be able to hold patents in their own name, but there is clearly much more than needs to be done to overcome the gender disparity in the patent system.

Many (this author included) consider Sarah Guppy a trailblazer. Unfortunately, the controversy surrounding her patent and the suspension bridge has somewhat clouded her legacy. This is a shame because her legacy extends far beyond one patent and one bridge. Her accomplishments are many and varied. Much like the Railway Bridge at Maidenhead, by today’s standards Guppy would have been considered an extraordinarily accomplished engineer; by the standards of the time Guppy’s achievements were simply sensational.

Written by Adam Kelvey, CIPA Fellow.

Date Published: 26 April 2023