British Pioneers of Control Systems

The Quiet Giants Who Gave the World Its Industrial Brain

Whenever the history of modern industrial control is told, the narrative almost always leaps straight to 1968, and an American engineer named Dick Morley working in a Massachusetts garage. That story is true, but it is only half the picture. Long before the first Modicon PLC flickered into life, Britain had already laid the theoretical foundations, built the world’s first programmable electronic computers, and installed some of the earliest digital control loops in steelworks, refineries and power stations. This is the British half of the story, the one that is too often overlooked.

1936 – Alan Turing

The Universal Turing Machine, Cambridge University While factories were still wiring banks of relays by hand, a 24-year-old mathematician published a paper entitled On Computable Numbers. In it, Alan Turing described a single universal machine that could be reprogrammed, simply by changing a paper tape, to perform any conceivable logical task. Every modern PLC, DCS, SCADA system and industrial PC is, at its core, a physical realisation of Turing’s 1936 concept. Without Turing there is no programmable control, full stop.

1943–1944 – Tommy Flowers

Colossus, Post Office Research Station, Dollis Hill, London To crack the Lorenz cipher used by Hitler’s High Command, engineer Tommy Flowers designed and built Colossus, the world’s first large-scale programmable electronic digital computer. By 1945 ten Colossus machines were in operation, each with 2,400 vacuum tubes and processing 5,000 characters per second in real time. Colossus proved that electronic digital machines could be reliable enough for continuous heavy-duty operation, a lesson American engineers would only rediscover a decade later.

1949 – Maurice Wilkes

EDSAC, Cambridge University Mathematical Laboratory, Cambridge On 6 May 1949 the Electronic Delay Storage Automatic Calculator ran its first program. EDSAC was the first practical stored-program computer in regular daily use anywhere in the world. Its mercury delay-line memory and von Neumann architecture became the template that every industrial controller still follows today.

1950s – Elliott Brothers (Borehamwood)

The ARCH series, the first computers sold specifically for real-time process control While the United States was still relying on analogue instruments, Elliott Automation was installing digital computers in British steel mills, oil refineries and nuclear plants. The ARCH 1000 (1958) and later ARCH 2000 series were among the very first machines anywhere to close a control loop digitally, reading thermocouples, calculating corrective actions and driving valves directly. Elliott’s work predated most American direct digital control (DDC) experiments by several years.

1951 – Ferranti Mark 1

The first commercially sold stored-program computer Delivered first to Manchester University and soon afterwards to industrial customers, the Ferranti Mark 1 was used for some of the earliest real-time data-logging and control trials in British chemical plants.

1960s–1970s – English Electric / ICL System 4 and 1900

series

Direct digital control in British heavy industry British Steel, ICI and the Central Electricity Generating Board were world leaders in replacing entire walls of analogue PID controllers with centralised digital computers. By the late 1960s some British plants were running hundreds of closed loops from a single machine, years before Honeywell’s TDC 2000 appeared.

1973–1974 – GEC-Elliott Process Automation

GEM-80, Britain’s (and Europe’s) first true PLC The American Modicon 084 rightly claims the title of first commercial PLC, but only five years later GEC-Elliott launched the GEM-80 (General Electric Modular 80). Rugged, ladder-logic programmable, rack-mounted and built from the ground up for the factory floor, the GEM-80 became the dominant controller across British and Commonwealth industry for decades. Tens of thousands were installed in steelworks, mines, water-treatment plants, railways and power stations.

1970s–1990s – Eurotherm

The PID controller that conquered the world Although not a PLC, Cheltenham-based Eurotherm turned the humble PID temperature controller into a global standard. Their bright-red 818, 820 and 900 series controllers, with their trademark “Eurotherm blue” displays, remain a familiar sight on factory floors everywhere.

British Legacy in One Sentence

America gave the world the commercial PLC in 1968. Britain gave the world the theoretical idea (Turing), the first programmable electronic computer (Flowers), the first practical stored-program machine (Wilkes), some of the earliest real-time industrial control computers (Elliott), and one of the very first rack-mounted programmable controllers (GEM-80).

The modern factory floor may speak with an American accent, but its intellectual DNA is unmistakably British.