It is with sadness that we announce the passing of Peter Thomas Houldcroft, a former Director of Research for TWI. He passed away peacefully, aged 97, on 3 August 2020, with his family rightfully announcing that “he was much loved and will be hugely missed.”

As a metallurgist, Peter began his career with the aluminium producer James Booth before moving to join the research arm of The Institute of Welding, the British Welding Research Association (BWRA). He worked from the London Park Crescent office, which was where the BWRA’s metallurgical research was undertaken, and worked on the welding of Al alloys. His early work focused on TIG welding behaviour before he began to research the joint properties of the newly-invented MIG welding process, which had been imported from the USA. As MIG welding became the worldwide process of choice for welding thicker Al alloys, Peter was a team member of the first UK-based demonstration project of an all-welded Al superstructure for a Thames launch.

It was around the same time that Peter developed the Fishbone test to quantify the cracking resistance of welded Mg alloys for aircraft fuel tanks and nuclear fuel canisters. He was then was at the forefront of a BWRA team developing weldable high strength Al alloys for military bridging and aircraft undercarriages.

BWRA’s Engineering Department had been based at Abington near Cambridge since 1946 and, in 1956, the London-based Metallurgy Group was moved to the same location. Peter moved with the group and went on to propose that welding research activities should be separated from metallurgy and engineering research, leading to the creation of a new Welding Technology Group, which Peter headed up. By 1964, Peter had taken over from Alan Wells as Director of Research after Alan left for the Queens University of Belfast.

It was during the early 1960s that Peter developed what was possibly his greatest contribution to engineering with the creation of what would later become a multi-billion pound industry. The BWRA was working with the British Navy and the Services Electronic Research Laboratory (SERL) on the development of laser welding. Peter used his expertise in metal cutting to propose the use of coaxially delivered oxygen for the laser cutting of metals. Despite being refused a patent application by the German examining body of the time, the idea and ensuing research eventually went on to create the worldwide laser cutting industry.

This ground-breaking research was not Peter’s only breakthrough at BWRA, as he also directed the build of the world’s first 2kW fast axial flow CO2 laser. This was the beginning of a new era concerned with the development of high power gas lasers for welding and cutting of metals, which was rapidly pursued worldwide.

His contributions to laser technology led to Peter being awarded the first ever UK Association of Industrial Laser Users’ medal in 1997, some eleven years after his retirement. Speaking at the time, Peter announced, “It has been 30 years since I invented gas assisted laser cutting at TWI and 11 years since I retired, so I quite expected that the event would have been forgotten.”

Of course, Peter’s expertise in laser processes could not be easily forgotten as he remained an expert in laser welding technology and in Al alloys until he retired from TWI (as the BWRA became) in 1986.

However, his influence over the continuing work of TWI can be felt today as Peter set up the first integrated Research Board in 1966 after all of the previous Research Committees were disbanded. This programme continues to work with many of the leading names in industry to guide the direction of TWI’s Core Research Programme. As part of his work with the Research Board, Peter won a succession of government grants to support a large programme of basic and applied research. Many TWI developments, which had worldwide impact, originated from this pioneering programme.

Outside of his work for TWI, Peter gave his time and support to the Institution of Metallurgists, becoming President in 1981 and then being elected to the Royal Academy of Engineering in 1985. He also authored many papers and books on welding technology, including ‘Which Process?’ and 'Welding and Cutting - a Guide to Fusion Welding and Associated Cutting Processes', which was co-authored with Bob John.

Following retirement, Peter wrote a 50 year history of the BWRA/TWI, which was published in 1996. The excellent book provides a detailed record of the early years of the BWRA, its staff and the formation and subsequent growth of TWI into an internationally recognised centre of excellence in joining and associated technologies.

For all of his many achievements, it is perhaps the tributes paid by those who worked alongside him that demonstrate the calibre of Peter Houldcroft as a person.

Richard Dolby, himself a former TWI Director of Research and Technology, said, “In all my dealings with Peter Houldcroft, he was always polite and kind, an inherently modest man and a mentor and role model to me for many years. Looking back, we had almost identical career paths and we were both fortunate to be able to contribute to an expanding and successful engineering organisation, which was internationally recognised as a centre of excellence. Peter's contribution to laser technology worldwide has been well documented and is a wonderful legacy coming from a long and successful career.”

A former colleague of Peter’s from TWI, Steve Jones, revealed, “Peter was the first person I met at TWI when I arrived for interview in early 1971. He struck me as a man with wide interests - in addition to a technical discussion we spent a fair amount of time talking about Stonehenge!” He continued, “Peter’s technical contributions were correspondingly wide-ranging, including working with Arthur Smith and George Salter on the development of CO2 welding and the first development of laser cutting. I remember Peter as a supportive manager, concerned with staff welfare as well as technical excellence,” adding, “In retirement he took a great interest in the history of Royston cave, publishing an analysis of its original internal structure and possible use by the Templars.”

Peter Houldcroft not only impacted engineering and the work of TWI with his many years of service, but also had a profound effect on all those who met him and will be greatly missed.