UK 04NC, FMS, Industrial Decline and Revival

Postwar and the beginnings of NC (1945–1959)

The postwar boom

After the war, Britain's machine tool industry first did well selling conventional machines. Total output rose from £72.1 million in 1948 to £183.4 million in 1957, and employment from 79,000 to 103,600^[1]. In 1956 makers' order backlogs amounted to 15 months at the current rate of production^[1]. In the same year, 1956, imports exceeded exports, and the trade unions complained that Britain had become a machine tool importer, but the Board of Trade replied that it was an exception in a year of especially heavy demand^[1]. The pattern seen in Chapter 3, in which imports swell when demand is high, continued here too.

Ferranti: NC driven by magnetic tape

The company that took NC research furthest in Britain was Ferranti, an electrical and defense firm. In the early 1950s the head of its division, J. N. Toothill, and the head of technical development, D. T. N. Williamson, went to the United States to see the NC research at MIT. After their return, NC research began at the Crewe Toll laboratories in Edinburgh. Hamilton's doctoral thesis dates the start to July 1952, while Williamson himself wrote in a 1958 article that it began in 1951 with research on how to make parts in small quantities^[1][2]. The trigger was the need to make many precision parts such as radar waveguides in small batches at a time when skilled machinists were in short supply^[1][2].

The prototype completed in 1955 drove a three-axis milling machine made by Du Four from magnetic tape. The designer marked the key dimensions, such as the centers of arcs and the ends of lines, on the part drawing; these were punched on paper tape and fed to a computer, which calculated the tool path in fine detail and wrote it to magnetic tape as a train of pulses for each axis. One pulse on the tape moved the tool 1/10,000 inch^[1]. Williamson believed that the hardest part of NC was not control but data handling. So he divided the work: a central computing service did the calculation, while the control unit placed in the factory contained only servos, making it cheap and slow to become obsolete. He also wrote that second-degree curves could be generated without approximation^[2]. One computer was estimated to be able to prepare tapes for about 50 machine tools, and Ferranti had computing centers in London, Manchester and Edinburgh^[1].

Optical gratings and moiré fringes: counting position

Another technology behind Ferranti's NC was the way it measured position. When two optical gratings ruled with fine lines are laid over each other at a slight angle, a pattern of fringes (moiré fringes) appears, and the fringes move when one grating is shifted. Counting these fringes with photoelectric cells turns the amount of movement into numbers in fixed increments. Ferranti applied for a patent on this method in 1955. The gratings, with 5,000 lines per inch, came out of research at the National Physical Laboratory (NPL) and could count an inch in 10,000 steps^[1]. Because the grating measured position directly instead of relying on the accuracy of the lead screw, another advantage was that the drive system could be chosen freely^[5]. It is the idea that leads to today's linear scales.

Olympia 1956, and three other attempts

In June–July 1956, Ferranti's first NC product was unveiled at the International Machine Tool Exhibition at Olympia in London. The aircraft maker Fairey Aviation saw it and proposed joint development^[1]. In the mid-1950s there were three other attempts in Britain. EMI used a system with interpolation circuits inside the control unit and teamed up with Cincinnati to drive a three-axis milling machine. British Thomson-Houston (BTH) fitted positioning NC, with hole positions commanded by punched cards, to a Kearns horizontal boring machine, which then machined in about half the time of manual setting. And Alfred Herbert, Britain's largest machine tool maker, studied an older method of recording a skilled worker's operations on magnetic tape and playing them back, but did not make it a product^[1]. That NC was pushed forward by electrical companies, not by the old machine tool makers, foreshadowed what was to become of Britain's machine tool industry.

In answer to criticism of the cost, in 1959 Ferranti brought out a cheap positioning-only system and the Mark IV, a three-axis continuous-path control. Through the work with Fairey it switched to hydraulic servos and transistor circuits, so that the system ran on an ordinary power supply^[1]. In the same year, 1959, a survey by the Department of Scientific and Industrial Research (DSIR) reported that Britain was still ahead in NC and should make the most of it^[1].

The beginnings of the coordinate measuring machine

As NC made machining faster, inspection could no longer keep up. In a 1958 article Williamson wrote that inspection could take as much as 100 times longer than machining, and argued for a machine that would move a probe to set points and record the position errors^[2]. In December 1959 Ferranti announced a measuring machine that measures parts by coordinates (Inspection Machine). Using the same optical gratings and electronic counting circuits as its NC, it displayed the position of a probe moved by the operator to 1/1,000 inch, with a measuring range of 24 × 15 inches. It was said to cut inspection time greatly compared with measuring with dial gauges on a surface plate, and to have no equal of its type anywhere in the world^[4]. The following year, 1960, Bendix of the U.S. began selling Ferranti's NC and measuring machine in America^[5]. It is an early example of today's coordinate measuring machine (CMM).

The spread of NC, System 24 and the touch probe (1960–1973)

NC sells less than hoped

In the 1950s “automation” boom, NC was expected to spread quickly. But when a trade journal looked in 1964, only 232 NC machine tools had been delivered in Britain by the end of 1962, or 547 including those on order, about a tenth of what had been forecast ten years earlier. More than 70% of them were for positioning holes, and continuous-path machines that could cut curves numbered just over 100^[1]. When the Production Engineering Research Association (PERA) surveyed 17 users in 1963, NC had cut machining time and cost by 40–60%. Even so, the buyers were mainly high-technology plants such as aero-engine works, or plants undergoing major modernization^[1].

For the slow growth of Britain's early NC, Hamilton blames poor marketing by the electrical companies and, more than that, the conservative attitude of the established machine tool makers themselves^[1]. Even so, more than 20 NC machines were on show at the 1964 Olympia exhibition, and British machine tool makers themselves, including Wadkin, Alfred Herbert, BSA Tools, Staveley-Richards, Archdale and Kearns, began selling NC machines^[1]. In 1966 the Minister of Technology told the House of Commons that NC was needed not to cut jobs but to make up for the shortage of skilled workers, and said the government would support the NC machine tool exhibition in May^[7]. It was in 1966 that the number of NC machine tools in use in Britain reached 800^[1]. Investment in machine tools in 1969 was £145 million, about the same as the year before, but purchases of NC were rising sharply^[15].

Herbert-BSA and Herbert-Ingersoll

In this era the machine tool industry sought to grow through mergers. In 1966 Alfred Herbert joined with Churchill Machine Tool and became part of the Herbert-BSA group^[6]. Then in 1966 Herbert-Ingersoll was formed with Ingersoll Milling Machine of the U.S.^[8][10], and it set up a new plant at Daventry in Northamptonshire. An American trade journal described it as a plant aiming to triple output per worker^[11][12]. But in June 1972 Herbert-Ingersoll went into receivership^[16][17].

The Molins System 24: a forerunner of the FMS

In September 1967, at the 8th International Machine Tool Design and Research Conference (MTDR) in Manchester, the cigarette-machine maker Molins unveiled System 24. It was led by Williamson, who had moved from Ferranti^[13]. Molins made 70% of the world's cigarette-making machines and needed to make small parts a few inches in size, in many varieties and small quantities. Williamson's team first studied the parts and found that 80–90% could be made of light alloys such as aluminum and about 70% would fit within 12 × 12 × 6 inches. Light alloys can be machined much faster than steel^[13].

In System 24, parts were fixed to pallets, and on the computer's instructions the pallets rode a conveyor system between the NC machines. The day before, the computer printed a list of materials and a list of machining programs; the preparation staff assembled the materials, and the next day, once the setup staff had mounted the parts on pallets, the machines did the machining in sequence. The first installation, at Deptford in London, consisted of two three-axis milling machines, two three-axis drilling machines, a six-axis machine and others, most of them machines with two spindles that cut two parts at once^[13]. A 1974 American report also cites System 24 as an advanced example of computer-controlled, high-variety, low-volume production^[14]. It is an early example of the FMS idea of linking several NC machines by transport and computer.

The touch-trigger probe

Rolls-Royce engineer David McMurtry needed to measure parts of Concorde's Olympus engine. The touch-trigger probe was what he devised for the job in 1972^[19]. The stylus sits precisely in a fixed rest position, and when it touches something and tilts slightly, electrical contacts signal it. Reading the machine's coordinates at that instant gives the position of the point touched. The British priority date for the patent is September 21, 1972; U.S. Patent 4,153,998 was granted in 1979, with Rolls-Royce as the assignee^[20]. In 1973 McMurtry and John Deer founded Renishaw Electrical Ltd and began selling the TP1 probe for CMMs^[19].

What changed on the shop floor. With the touch-trigger probe, a CMM could take the coordinates of a point just by touching it with the stylus. In 1977 Renishaw brought out a probe for machine tools, so that locating the work (setup) and inspecting it after machining could be done automatically without taking it off the machine^[19]. This was the beginning of the “on-machine measurement” now taken for granted on machining centers. How probes are used is also touched on in the 5-axis machining page.

The import wave and the fall of Alfred Herbert (1974–1989)

The state rescues Alfred Herbert

In the 1970s the decline of Britain's machine tool industry became a political issue. On October 29, 1974, the government guaranteed the overdraft of the loss-making Alfred Herbert, at first up to £5 million. On July 9, 1975 it decided on support of up to £25 million, and in August it also announced a support scheme for the whole machine tool industry under the Industry Act^[21]. On December 2 the House of Commons approved £26,179,765 for Herbert Ltd, a government holding company. The plan was to buy Alfred Herbert's shares at 6 pence each, put the rest into capital and loans, and transfer the holding to the National Enterprise Board (NEB). The government's spokesman admitted that the company's problems were deep, that it had too many people and too wide a range of models^[21].

“46% of home demand is imported”

A House of Commons debate in January 1979 conveys the situation well. A Labour member charged that the old firms had neglected investment and new designs and relied on reselling foreign machines and on old standard products, and said that imports of NC machine tools were about three times exports and that Ford had gone as far as Taiwan and Brazil looking for capacity to make dies and jigs^[22]. Replying for the government, the minister countered that the British machine tool industry's sales in 1977 were just under £400 million, of which nearly half, £185 million, was exported, against imports of £144.4 million, and that in multi-spindle automatics and special-purpose machines for engine blocks Britain could match anyone in the world. But he also admitted that British industry as a whole relied on imports for 46% of its demand for machine tools^[22]. Exports were high, yet factories at home bought foreign machines. Chapter 3 showed the same pattern between the wars; it was now repeated in the age of NC.

1980: the liquidation of Alfred Herbert

State support bore no fruit, and in 1980 Alfred Herbert went into voluntary liquidation^[6]. Founded in Coventry in 1888, it had been at the center of the state's control of machine tools in both world wars. Coventry's city history describes the collapse of Alfred Herbert, once the world's largest machine tool maker, and the sight of its machines put up for sale in deserted works, as a symbol of Coventry's slump in the early 1980s^[23]. After the liquidation, the business under the Alfred Herbert name went on making CNC machine tools, but in April 1983 the receiver put that business and its assets up for sale^[31][32]. Remembering that in the 1950s Herbert's research department had studied the old method of recording skilled workers' operations rather than the electrical companies' NC, one could say the difference in choice of technology came out here.

The Japanese plants arrive

As if taking the place of the vanishing old British firms, Japanese machine tool makers set up plants in Britain. In July 1980 Yamazaki Iron Works of Japan (today's Yamazaki Mazak) established a British company, Yamazaki Machinery U.K. Ltd^[26][27], and in June 1987 its European plant in Worcester began full operation as a computer-integrated manufacturing (CIM) factory. Today it covers 29,000 square meters and employs over 900 people^[27][33]. In March 1988 this British plant exported CNC machine tools to Japan for the first time^[27]. Japanese machine tools came into Britain, and Japanese machines built in Britain went back to Japan. It was a major reversal in the history of British machine tools.

Meanwhile, British technology companies grew through measurement and software. Renishaw expanded to the U.S. and Ireland in 1981, and brought out a laser interferometer for measuring machine tool accuracy in 1987 and encoder readheads in 1989^[19]. In CAM, Delta Group took over research on surface CAD/CAM that had begun at Cambridge University in the 1960s and 1970s, and started selling software in 1980. This later became Delcam^[25].

Living by measurement and research centers today (1990–)

Measurement and CAM companies

In 1990 Delcam's employees bought out the company and set up its headquarters in Birmingham. It went public in 1997, and by 2009 it was a CAM company with more than 30,000 customers^[25]. In 1991 Renishaw brought out the QC10 ballbar, which has a machine tool trace a circle to check its positioning errors in a short time; in 2005 its REVO five-axis measuring system for CMMs made touch measurement about 10 times faster; and in 2011 it moved into metal additive manufacturing^[19]. Britain's standing as a builder of machine tools has fallen, but in tools for measuring, adjusting and programming machine tools, British companies are still inside factories around the world. How CAM is used today is covered on the CAD/CAM page.

The old firms that survived

Some of the old machine tool makers survived in changed form. Holroyd of Rochdale, founded in 1860, patented a thread milling machine in 1897. In 1993 it won a Queen's Award for its rotor cutting and grinding machines, and today, as Precision Technologies Group, it exports 98% of its products^[34]. The 600 Group, which owned the lathe makers Colchester (bought in 1954) and Harrison (bought in 1971) and was Britain's leading lathe maker, sold its machine tool business in April 2022 and became an industrial laser company^[3].

Research centers: the AMRC and MTC

In the 21st century Britain is trying to develop manufacturing technology through research centers shared by universities and industry. The Advanced Manufacturing Research Centre (AMRC), set up by the University of Sheffield with Boeing in 2001,^[35] became the core of the Advanced Manufacturing Park, begun in 2004^[37]. In 2010 three universities, Loughborough, Birmingham and Nottingham, set up the Manufacturing Technology Centre (MTC) in Coventry^[38]. The AMRC is now part of the national network of high-value manufacturing research centers (the High Value Manufacturing Catapult) and works with more than 120 companies, including Boeing, Rolls-Royce, BAE Systems and Airbus^[40]. By a turn of fate, Coventry, once home to Alfred Herbert, now has a manufacturing research center.

Britain today in numbers

According to 2023 figures from the trade association, the Manufacturing Technologies Association (MTA), Britain's machine tool production (sales) in 2021 was £488 million, with exports of £538 million and imports of £518 million. Britain is ranked as the world's 16th-largest machine tool producer and 18th-largest market. Production of measuring equipment, on the other hand, is about £1 billion, roughly twice that of machine tools, and a very high share of it is exported^[39]. From a country that builds machine tools to a country that earns its living by measuring: the numbers, too, show Britain's postwar course clearly.

⛩Links with Japan

The relationship between postwar Britain and Japan in machine tools changed direction greatly over time. The 1950s were when NC research was beginning in Japan too (for the beginnings of NC in Japan, see Japanese Archive, Chapter 2, “The Lineage of Milling Machines and Machining Centers”). By the 1980s, however, Japanese machine tool makers were building plants in Britain and had become the side handing over technology. In 1983 Yasuda Industries licensed the manufacturing technology of its YPC30 machining center to a British machine tool maker, followed by the YPC45H in 1986^[30]. In 1987 Yamazaki Mazak's Worcester plant went into full operation, and the next year it shipped CNC machine tools from Britain to Japan^[27][41].

In the other direction, Britain's “measuring technology” entered Japanese factories. Renishaw opened an office in Japan in 1982 and set up a structure to support Japanese machine tool and measuring instrument makers directly^[29]. The touch probes for on-machine measurement and the ballbars used in Japanese factories are, as this chapter has shown, tools that became products in Britain. The statistics tell the same story: in 2020 Japan was the second-largest source of Britain's machine tool imports, after Germany^[39]. How Japan's machine tool production and exports overtook Britain's can be seen in The History of Japanese Machine Tools in Numbers.

FAQ

How did Britain's Ferranti NC differ from MIT's NC in the U.S.?

Both calculated the tool path by computer, but Ferranti's idea was to leave the calculation to a central computing service and keep the factory control unit cheap, with only servos following pulses on magnetic tape. Position was counted directly with the moiré fringes of optical gratings. Research began in Edinburgh in 1951–52, and the product was unveiled at the Olympia exhibition in 1956.

Who built the first coordinate measuring machine (CMM)?

A well-known early example is Ferranti's coordinate measuring machine (Inspection Machine), announced in December 1959. Using the same optical gratings as its NC, it displayed the position of the probe in figures to 1/1,000 inch, and a trade journal of the time wrote that there was no other machine of its type in the world. Because the answer depends on how “first” is defined (prototype, product or volume production), this page only gives the year of the announcement and what it was.

Why is the Molins System 24 called a forerunner of the FMS?

Because System 24, announced in 1967, was a scheme for linking several NC machines with a pallet conveyor system and a computer to machine many kinds of small parts in sequence. It separated setup (mounting parts on pallets) from machining, and the computer issued the material and machining schedule the day before, so it already had the elements of the later FMS.

Why did Alfred Herbert fail?

The parliamentary record points to continuing losses from having too many people and too wide a range of models. In 1975 the state rescued it through a holding company and it came under the National Enterprise Board (NEB), but it could not be turned around and went into voluntary liquidation in 1980. For the industry as a whole, Parliament also criticized the lack of investment and new designs and the reliance on reselling foreign machines.