When David Davies, who has died aged 89, was asked by John Prescott, the then deputy prime minister and transport secretary, to undertake an inquiry into the safety system on Britain’s railways after the Ladbroke Grove train crash of 1999, the BBC could not conceal its excitement. The report said: “Sir David Davies may not be a household name, but he is among the few people that the term genius can be applied to without overstatement.”
Davies – known universally as Den, taken from his initials – probably enjoyed this description. Aged 12, while at Llandaff Catholic school in Cardiff, he knocked on the headmaster’s door to complain he was not being intellectually challenged and asked, successfully, to be moved up to the next class. He went on to a glittering career in industry and academia.
Consequently, described by his colleagues as utterly unflappable and always calm, he did not hesitate to take on the task offered by Prescott, which came at a crucial time in the midst of something of a national panic about the state of the railways. The Ladbroke Grove disaster, in which 31 people died, was the worst accident on the railways since 1988 and the second major crash caused by a train going past a red signal, after Southall two years previously. There was widespread concern among the public that the railways were not safe and that not enough was being done to improve the situation.
Fortunately, Prescott avoided a kneejerk response to public outrage, and instead put his trust in Davies, who had the relevant experience for the job. He was not only at the time the president of the Royal Academy of Engineering, a fairly new national academy whose creation had been at the behest of Prince Philip, but he had also worked in British Rail’s research department in the late 1960s and was familiar with the workings of the railway. His approach was meticulous and at the time controversial.
His report, published in early 2000, was a thorough assessment of the two main technologies that were capable of reducing the risk of drivers failing to stop at a red signal. At the time, the newly privatised railways were introducing a fairly simple Train Protection & Warning System, which was very effective but did not prevent certain types of overrun, notably if trains were going particularly fast. However, because the alternative system, Automatic Train Protection, was several times more expensive and would take far longer to install across the network, Davies strongly recommended the former, arguing that it would ultimately save more lives because of its rapid implementation.
The intervening quarter of a century has proved that he was right. The number of signals passed at danger on the railways has been reduced dramatically and, while there has been the occasional near miss, there has been no major accident involving signalling on the railways since then. His approach, of getting a good system implemented quickly rather than a perfect one brought in more slowly, was proved to be a brilliant judgment.
Davies later briefly chaired an organisation called Railway Safety, which was set up to promote safety issues, and he focused on the poor state of much of the fencing protecting the tracks. This came to the fore after the 2001 Selby train crash, when a Land Rover tumbled down an embankment and caused two trains to collide, killing 10 people.
Born in Cardiff, to Sarah (nee Samuel) and David Davies, an estate agent, David Jr studied electrical engineering at the University of Birmingham, and was awarded his PhD in 1960; he later joined the staff. He met his future wife, Enid Patilla, there, but waited seven years before proposing to her as, he revealed later, he wanted to make sure he could provide for his future family. After several academic posts, notably at University College London and Loughborough University, where he was vice-chancellor, he became chief scientific adviser to the Ministry of Defence in 1993, and the following year was knighted.
While his Ladbroke Grove report was his most publicised work, it should not overshadow Davies’s remarkable achievements in scientific research, which was the source of the BBC’s approbation. His research work was varied, covering work in antenna arrays, radar, signal processing and optical fibres.
It was the developments in the last of these that were particularly groundbreaking, as he invented fibreoptic sensors, which could provide sensitive measurement of quantities such as strain or temperature, and could even be the basis of a kilometre-long microphone with high dynamic range. All this was despite the fact that fibreoptic cables were at the time being championed in telecommunications for their insensitivity to disturbances and therefore unable to be used in this way. His research opened up a huge potential market for the wide use of fibreoptics.
Consequently, for this work he won the Rank prize for optoelectronics in 1984. He later also won the Institution of Electrical Engineers’ Faraday medal in 1987. He served on the committees of many national bodies, including the BBC engineering advisory committee and the Royal Society’s science inquirycommittee.
Enid died in 1990. In 1992 he married Jennifer Rayner, a chartered surveyor. She survives him, as do his two sons, Michael and Christopher, from his first marriage, and his stepdaughter, Ruth.
• David Evan Naunton Davies, engineer and government adviser, born 28 October 1935; died 19 August 2025
