Michael Reece, brilliant engineer who helped develop the vacuum interrupter, a core component for modern industry

Oct 23, 2023

Michael Reece, who has died aged 91, led a team at the Electrical Research Association (ERA) which developed the world's first "contrate" contact vacuum interrupter.

In layman's language, this is a safety switch which uses electrical contacts in a vacuum. It is today a core component of circuit-breakers widely used in power transmission systems, power generation units, and power distribution systems for locomotives and industrial plants.

Mike Reece was a hands-on engineer, and one of his greatest successes was in resolving electrical interference issues with the Class 91 high-speed electric locomotives deployed by British Rail from 1988 on the East Coast main line.

Anthony Brown, who went on to become Chief Engineer of Great North Eastern Railway (GNER), recalled meeting Reece in 1989 when he arrived at Bounds Green depot in north London to sort the problem out.

"I’ve got all the equipment with me that I need," Reece announced, though he had only brought with him a slim folder. Within an hour he had decided on the solution – an air-cored inductor mounted on the roof – and had sketched it out on a sheet of paper.

BR engineers had also spent months trying to address wear rates on the Class 91s’ traction motor brushes to make them last 50,000 miles longer, but to no avail. Over lunch one day, Reece advised them to ask the manufacturer to increase the brush length by 5mm.

The problem was solved, and the Class 91s have each gone on to clock up more than 7 million miles in service. The first has only recently been withdrawn, as Hitachi-built Azuma trains take their place on expresses out of King's Cross, and some will gain a new lease of life on other routes.

Vacuum circuit-breaking technology was developed in the US in the 1920s, but remained non-viable until the 1950s, by which time expertise had improved. The technology offered huge potential advantages over other circuit-breaking techniques, being self-contained, needing no supplies of gases or liquids and no maintenance; it was also non-flammable, silent and required only a small amount of energy to operate.

In Britain, English Electric and the member companies of what became AEI (Associated Electrical Industries) became involved in the research effort along with the ERA.

Reece started work on the technology in 1953, and went on to publish a number of reports within the ERA. The work was secret at the time, and was only finally made public in his seminal article "The Vacuum Switch and its Application to Power Switching" (1959), followed by "The Vacuum Switch" in 1963.

Reece was primarily concerned with developing systems that would overcome problems of localised overheating, which limited the capability of vacuum interrupters to disrupt electrical current. The answer was a device known as a "contrate" contact, a cup-shaped copper contact with angled slots in the side.

In 1968 the contrate arc control system was patented; Reece's prototype, made in 1966, is now in the Science Museum in London.

Michael Peter Reece was born on August 12 1927. His father, a ship's captain, died when Mike was young, shortly before taking up an appointment as harbour master at Dartmouth; his mother was a concert pianist.

Reece graduated from Manchester University with a degree in Electrical Engineering, and after working with the ERA, he moved to AEI, then GEC, eventually becoming R&D director for GEC Alsthom at Stafford.

He was awarded a PhD for fundamental research work he did into the operation of high-voltage fuses and protection systems.

A member of the Royal Academy of Engineers, Reece was a mentor to many younger engineers. He believed that "no question is too stupid, there are just some stupid answers", and his definition of an expert was: "X marks the spot, and a spurt is a drip under pressure."

Diminutive and self-effacing, Reece had a passion for engineering, and his mind was always working. At the Royal Albert Hall one evening with his wife for a concert, he calculated the weight of the air in the building at eight tonnes.

His wife Margot, a senior administrator in the BBC music department, died in 2016. There were no children.

Michael Reece, born August 12 1927, died June 3 2019