A Brief History of STL

The Early Years


Shortly after the end of the second world war STC had decided to re-establish research facilities. Until the middle of 1931 a laboratory which could be considered the forerunner of STL had been established within ITT operating in premises formerly occupied by the Royal Air Force on Hendon Aerodrome. This laboratory suffered the fate of many similar institutions following the depression.

The new facilities were to be established in an existing plastics and cable factory in Progress Way, Enfield as a temporary measure. The company was to be known as Standard Telecommunication Laboratories and the date of formation was 1st. December 1945.

At that time the new company's Managing Director was Mr.A.W.Montgomery, the Assistant Managing Director was Mr.T.R.Scott, the Administrative Manager was Mr.N.B.Noble, and the Personnel Manager was Mr.P.J.Rogers.

The early days of STL were most interesting, rewarding, frustrating and at times quite difficult. The lack of supplies in the way of furniture, stationery, or any other fixtures and fittings necessary to set up the new laboratories was a problem. The activity at Enfield had been a plastics and cable factory where there was one rather large wide open space and very little else. It was a question of the Plant Engineer and P.J.Rogers himself attending auctions and sales and obtaining items from other STC Companies. To buy or borrow a typewriter was almost impossible in those days, it was a matter of bullying someone to lend you one. STC unfortunately were not able to help to any great extent as they required the items for themselves in opening up the new factory in Newport. However individuals were most helpful and kind. For instance it was almost impossible to get things like application forms printed. Mr. Thompson, the Personnel Manager at New Southgate fortunately had a very good supply and made a few hundred available.

It was no mean job to find the staff to work at the new laboratories. There were very few people of the level or qualifications required available and consequently people like Dr.A.T.Starr, who joined STL from Malvern and who was in contact with colleagues from the past, would try to interest them in STL.

As we had had over six years of war, materials and components were in very short supply. We had to find alternative supplier which in fact turned out to be Government surplus stores. Some of the items were of special importance because of the value of the components they contained for the work which we were engaged on. Two notable ones were the gunsight predictor, which contained motors and gears, and the Pye IF strip which contained many components and valves, EF 50's, in those days very much sought after.

At the end of 1946 the number of staff totalled 217. This was to grow to 408 at the end of 1950.

Some prominent names in the group at that time in addition to Mr. Montgomery and Dr. Starr were Harry Grayson, Norman Moody, Geoff Dawson, Harold Walker, Alec Reeves, E.P.G.Wright and Roland Dunkley.

Some of the earlier projects in which they were involved were the double beam oscilloscope which allowed something like three megacycles bandwidth and the automatic impedance bridge, shown at the first Physical Society Exhibition, which allowed one to clip a component across the terminals and it would sort out its type and read the value of inductance, capacitance or resistance to an accuracy of 1 percent.

Then there came the larger projects like the microwave link employing between twenty and thirty people, wavemeters and linear accelerators requiring the building of lead walls weighing several tons.

The wideband microwave links were a particular speciality. They were of great interest as television was obviously here to stay and multi-channel telephony systems were being developed.

A SHF Microwave System was designed by Dr. Starr’s group using a travelling wave tube amplifier invented by Rudolf Kompfmer when he was working for the Admiralty and developed by STC Paignton (D.C.Rogers). The system was taken over and engineered for production by STC Transmission Division for the GPO order for carrying television signals between Manchester and Edinburgh. This was the first application of SHF outside North America and the use of the travelling wave amplifier was the first application in public service in the world. The Manchester to Edinburgh link was actively put into service in early 1952, a month before it was due for acceptance by the GPO in order that the funeral of the late King George VI could be shown in Scotland. The time elapsed between the invention and the actual in service use of the travelling wave amplifier of about 7 years was exceptionally short.

The Electronic Switching Division, headed by Alec Reeves, was originally involved with ITT Laboratories at Nutley in the development of electronic switching and the original switch was the cyclotron, a cathode ray device, around which a twenty-four channel PABX was developed and demonstrated in New York in1946. Alec Reeves however had ideas of developing a hard gas tube for switching purposes and A.H. Beck and G.H.Hough took over this feature. Reeves was, of course, only concerned with digital transmission and switching and all his work was therefore in this form of transmission. Reeves submitted a number of futuristic patents on electronic switching but, like pcm, they were ahead of their time and lacked the techniques for their development. STL work on electronic switching was therefore discontinued in 1949.

From 1946 to the middle 50’s the initial work of 1470 Division covered telephone switching and telegraph applications. Systems design was by D. A. Weir, J. Ronayne and J. Rice with Manager E.P.G.Wright always available to assist, particularly in his inventive capacity. Laboratory work, circuit design and prototype development was controlled by D.S.Ridler with able backup chiefly from A.D.Odell. Early work included the development of telegraph regenerators, a code bar switch and associated switching system and testing signal imitation (on behalf of CCITT who were trying to design and introduce a new international signalling system). Around 1950 ITT/STC decided to suspend telephone switching applications at STL. Fortunately about this time STC became involved with J. Lyons in the development of LEO, (Lyons Electronic Office), a computer system for payrolls, bread delivery forecasts and similar work to release office staff for other operations. STC approached STL to design the preparation of data in a form suitable for computer operation, the input (decimal to binary conversion), the output (binary to decimal conversion) and the ultimate paper results. System design was by D.A.Weir and J.Rice backed up by E.P.G.Wright. Design of circuits, a high speed magnetic tape machine and the necessary equipment practice was dealt with by D.S.Ridler and his team. The equipment was installed for trials in Cadby Hall but, although the design proved entirely suitable, it was finally removed because the high speed gas filled counting device that was extensively used in the circuitry lacked the extremely high reliability required. The gas tube was the STL decatron.

Because of this computer experience the Transmission Division asked us to produce a system to reduce the work involved in filter design. A team consisting of J.Rice, P.W.S.Harrild and D.G.Hunter designed a computer called STEP 1 based on magnetic drum storage and the laboratory again developed the circuits and equipment. This was one of the first electronic stored programme computers to go into active service. Subsequently STC were approached by the Dutch PTT Research Laboratories (NSEM) for assistance in developing a new computer and asked STL to provide the expertise. In consequence J.Rice worked in conjunction with the PTT, who had the basic idea, to design the practical concept, later to be produced at Newport by STC, known as ZEBRA. STL also developed the required circuitry together with the magnetic drum storage system. For some years ZEBRA was the UK's largest export - over twenty systems.

During this period as a result of development work on the magnetic drum and inspired by E.P.G.'s inventive imagination, an automatic message switching system known as STRAD, using magnetic drum storage was developed. A prototype of the basic system was produced and proved its feasibility but a decision was taken to cease work on it. However the BPO took an interest and decided to use STRAD for message switching at the new Gatwick Airport. STL therefore continued producing circuits for this requirement but design and development were moved to New Southgate, J.Rice and G.G.Smith to provide the basis of the team.

Also during this period some research continued on storage devices, transistor circuit design and their applications to systems but about this time the majority of the remaining staff were transferred to other parts of STC.

On the technical front one of the main projects during this period was the development of semiconductors. Fundamental research brought about the "silane" process for the manufacture of silicon of the highest purity.

Valve operated equipments were the norm, there were large valves being replaced by smaller and smaller valves and then the point contact transistor happened. It was said that it took twenty years to put a second whisker onto a crystal and twenty seconds to put a third but that didn't work! However point contact transistors were tested extensively. They were very limited in their performance but then junction transistors arrived.

There was much speculation as to what success they would achieve. At that time there was no way of telling where it would all lead. In fact the semiconductor era had arrived and soon there were junction diodes and photocells as well as transistors. Small high-value tantalum capacitors had also been made and the new range of components made possible the construction of an advanced intruder alarm system with phenomenal (for that time) range.

As the work grew in volume and importance the accommodation at Progress Way could no longer cope and outstations were established to accommodate small specialised groups. One of these was Frogmore Hall in Hertfordshire where a substantial stretch of level ground proved invaluable for laying out long lengths of a novel helical waveguide to test its transmission properties. This led, in 1959, to a demonstration of the possibilities of this system carrying television programmes or equivalent information in various forms.

The techniques which made this possible included pulse code modulation invented by Alec Reeves in 1938. This technique requires all the different types of signal to be converted into coded trains of pulses, transmitted and then decoded at the receiving end. As it proved, the invention was twenty years ahead of its time and had to await the arrival of semiconductors and integrated circuitry in order to be fully exploited. The turning point probably occurred in 1960/61 when, with extensive cooperation from our Spanish house (SESA) and the Spanish Administration (CTNE), an experimental pcm junction telephone link was put on field trial in Madrid. This led STC to develop their first commercial pcm junction system for the British Post Office.

The Thrifts near Ware was another large house taken on to accommodate Mr. Ralph's team specialising in general transmission systems. From here staff travelled the world carrying out surveying and planning tasks.

The move to Harlow

It became apparent that a move was essential. During the early 1950's discussions had taken place on the possibility of new sites in the Enfield area but none suitable were available.

If a move from Enfield was to take place a site in Hertfordshire seemed ideal as housing would be available. Parts of the county also offered the necessary travel facilities, train and bus routes to Enfield and London, and were in close proximity both to several other STC locations and to many technical colleges.

The site had also to offer adequate room for expansion and provide the special facilities required by the laboratory of open space for outdoor radio and optical experiments. Facilities for indoor and outdoor recreation were also high on the list.

Three sites were short listed, one of which has since become a modern Tesco Superstore, with a strong preference for The Hall, Woodgreen Park in Cheshunt. The site had been requisitioned by the Ministry of Supply throughout the war years for experimental work on testing munitions and small arms and was in a very dilapidated condition.

Although the site was, for the most part, shielded by thick woodland it was in the green belt and feelings were at that time running high on such developments. The requisite planning permissions were sought and although these were initially granted at local level Ministry approval could not be obtained.

It was evident that there was a very vociferous local lobby led by a Harley Street physician, his historical novelist wife and a member of the chamber of a leading London QC.

The Company was, in its turn, able to lobby a large number of senior Government Ministers and Service Chiefs because of the importance of the work being carried out at STL to the armed forces and the post war economy in general. Sir Thomas Spencer was a frequent visitor to Whitehall at this time. Eventually at the end of 1955 an appeal was convened but unfortunately the notice given was rather short. The objectors claimed that the Government was attempting to bulldoze the proposals through. The Public Enquiry attracted large coverage from the national press. Accusations of another Crichel Down were made and several graphic descriptions of the results of building a research laboratory in the green belt printed. The Appeal ruled against the development and searches for a further suitable new location commenced.

In 1959 STL moved from Enfield to a modern laboratory complex set in seventeen acres on the edge of Harlow New Town. A total staff of around 500 made the move and continue to form the nucleus of the laboratories as they are today. Mr. R.A.Butler, who was then Lord Lieutenant of the County of Essex, carried out the official opening.

In 1962 Mr. T.R.Scott retired and Mr. J.D.Clare took over and set about making the research laboratories the most modern in Europe. STL's original brief to carry out telecommunications research and development in support of STC, ITT Companies, British Government Agencies and the British Post Office was maintained and widened to include research on materials, components, devices and systems and the planning of their world wide use. The aim was to concentrate on research that could not be expected to mature in less than five years.

As a result of this brief and following on the current development activities for pcm, a paper was written in 1966 by K.C.Kao and G.A.Hockham containing the world's first published proposal for a wideband optical communications system, a subject which was to win Kao and Hockham the Rank Prize for optoelectronics. The paper proposed information transmission by light signals through hair fine fibres of glass as an alternative to electrical signals through metal wires.

Although the paper opened the floodgates for optical fibre communications research it was not until 1977 that STC installed the world's first repeatered optical fibre system designed to operate at 140 Mbit/s over a 9 km route between Hitchin and Stevenage.

In the 1960's it became apparent that STL was expanding into two groups of distinct but interacting laboratories, one for materials and components and one for telecommunications, each with its own Technical Director and administration.

The materials and components laboratory was formed to evaluate new materials suitable for component development and to undertake fundamental research into component design up to the prototype stage. In order to carry out these tasks ultra-high pressure, ultra-high vacuum, spark micro-engraving and many more sophisticated facilities were established. The results were gallium arsenide infra-red lasers and a large range of semiconductor devices and integrated circuits to benefit the telecommunications systems and other activities.

In their turn the telecommunications laboratory were developing new systems, each generation multiplying by many times the number of circuits that could be carried over one pair of conductors or one optical fibre to keep pace with the rapid growth in demand for telephone and data communications facilities.

By 1967 all the tools of modern science were being harnessed to manufacture integrated circuits in their hundreds on slices of silicon which in turn were being interconnected on the slice to form integrated-integrated circuits resulting in the first large scale integration (LSI) systems. Computers were used to produce wiring diagrams and to assist in the fabrication and testing of the devices so designed. With these new methods the designer had to consider everything from materials technology to maintenance in service.

STL was particularly well set up to work in this mode. Within one building were the research groups covering most of the relevant skills and, by close contact with STC, there was ready access to production activities.

The year 1967 was also a milestone for expansion. To accommodate the rapid advances in technology a new laboratory was opened by Edward Short (the then Secretary of State for Education and Science). There were a further series of open days organised around this event. A marquee was set up and a thousand people were invited to visit. There was a press day with enormous coverage in the media, and the Saturday was given over to staff and their families. There were also specific days allotted to VIP's, learned societies and universities.

This all resulted in increasing the awareness of STL. Graduates were welcomed to come and see the facilities available and the programmes being conducted to enable them to decide whether they would like to work there or at least maintain contact for cross fertilisation of ideas.

Awareness even spread to local schoolchildren. At one time Fred Hiles remembers three ten year olds from the local primary school wrote in to say "please could they come and see our computer". They were given a very nice day with lemonade and cakes and a very senior computer man, Martin Lawn, gave them the full conducted tour of the computers.

During the 1970's Managing Director Mr.J.D.Clare retired in favour of Mr.S.B.Marsh who was in turn followed by co-directors Mr.D.S.Ridler, Dr.J.Evans and Mr.E.A.de L.Young. The laboratories continued to expand in both the main areas, Desmond Ridler directing telecommunications and electronics and Joe Evans materials and components.

One aspect of the continued expansion was the formation of a third division, Programming and Computing Services to service the needs, not only of the other two divisions, but also those of some other STC locations.

STL had become one of the largest communications research centres in Europe. It held the unique position of being the only British research centre to study all aspects of communications technology. This comprehensive capability was widely recognised and resulted in STL becoming the research centre for ITT Europe. By the end of the decade some 25,000 international scientists, engineers and notables were attending meetings each year in the well equipped conference rooms.

STL entered the 1980's as a laboratory complex with just over 1,000 staff, many of them PhDs, engaged in a variety of disciplines which formed an organisation designed to promote the technical feasibility of new or improved products.

Although STL had always advanced with the times and was up to the minute in its outlook, by the time that Dr. Jack Shields took over as Managing Director in 1981, rapidly changing commercial requirements needed attention. After analysing the activities of the laboratory he made it his immediate task to restructure STL.

The present commercial requirements demand that, despite the fact that their technology content is increasing rapidly, products must reach the marketplace very much faster than hitherto. They must have low unit cost and they must be capable of integration both with existing and future equipments.

These factors made three major changes necessary. The first was the appointment of Mr.Desmond Ridler as Executive Director of Technical Programmes and Dr. Ken Batsford as Director of Technology Transfer. The second was the formation of an Executive Committee to direct the policy of STL. The third was merging of the three separate laboratories into one with the technical activities divided among six major divisions each reporting directly to the Managing Director.

These new divisions were:-

Early in 1983 STC continued on its major organisational change and in particular the direct interest of ITT in STC altered significantly. Dr. Shields left STL to become Executive Director (Technical) of STC with the responsibility of Technology Planning and Administration, Product Styling and Design and Special Projects.

Mr. B.D.Mills took over the role of Managing Director of STL in July 1983 and led them into their 40th. year and beyond. With a background of long service in senior positions with STC, and sensitive to the need for closer, more direct cooperation between STL and the STC development and manufacturing companies Bernie Mills set about the task of organising the laboratories accordingly, a task which was to take up a major part of 1984.

A merger of STC and ICL, which took place in September 1984, was seen to present new and great opportunities for both parties. Although marred initially by a general depression in the electronics industry, to which STC was particularly vulnerable, and marked by a sharp drop in sales of components and high interest rates, this new partnership was seen by many to be a natural realisation of the “convergence” of data processing and telecommunications technologies. While the prospects for the merger looked bright at the strategic level STC was about to enter a period of declining confidence which resulted in a further restructuring under its new Chairman, Lord Keith of Castleacre.

Major changes took place, from Boardroom downwards, leaving a much trimmer organisation better suited to meet the foreseen challenges. STL took its share of the trimming down process with a programme of redundancies and early retirement involving in all about one hundred people.

In October 1985, Bernie Mills retired and was succeeded by Mr. P.J.Cropper. Previously Managing director of IDEC, a major systems engineering company, originally of ITT but latterly of STC, and with a background of senior positions in ICL of over ten years, Peter Cropper brought with him a timely and valuable knowledge of ICL business philosophy and methods and an appreciation of the potential of the STC/ICL merger.

As part of a new restructuring programme the company name ”Standard Telephones and Cables Limited” became “STC PLC”. “Standard Telecommunication Laboratories Limited”, reorganised to include an ex-ICL systems engineering and software contingent, became STC Technology Limited, the effective date being 25th. November 1986.

A casualty of 1986, after some 50 years as a coherent entity, was the Systems Planning Group, whose members were dispersed among the technical divisions. The Divisional Manager of the Group in its final years, Geoff Dawson, had first joined STL in 1946, had been Chief Engineer of STC’s Microwave Systems Division, and had held senior management positions at STL since 1967. In view of his association with the subject it was appropriate that he should have been invited to deliver, in March 1981, the Memorial Lecture “50 Years of Cross Channel Microwaves” at the IEE, Savoy Place, London.

Just before his retirement, Mr. P.J.Rogers was asked to comment on the marvellous spirit that there has always been in STL. He said that “I feel that it has always been there from the word go. We were a family and that didn’t just happen. It was a deliberate attempt by Mr. Montgomery, Mr. Scott and all the subsequent Managing Directors and Senior Managers to develop the spirit. Probably the best indication of this can be taken from the Athletic and Social Club. The support given to the A&SC was, in my long experience of social clubs, far beyond that which I have ever experienced. There was never any lack of support for the various functions. Probably the most indicative is that, where one is forming any sort of association, it is usually necessary to press-gang someone into being secretary or treasurer. We were almost embarrassed by having sometimes as many as five or six volunteers for the various positions. I think this in itself is an indication of the spirit and willingness of people to contribute to the various aspects”.

The Athletic and Social Club was formed on paper on 1st. September 1946, but a number of evening functions and socials had been run from the start of the year. There was even a Christmas function in December 1945 for about two dozen people. The early events were Beetle Drives, Whist Drives, Table Tennis Tournaments and a number of other functions. The actual club was formed, the first Management Committee appointed and the rules and regulations devised on 1st. September 1946.

Since that time the A&SC has grown from strength to strength, the number of activities and social events changing to meet the current need.

One of the most successful events organised over the past years has been the Retired Colleagues Dinner first held in 1972 during the Chairmanship of Arthur Brown. The A&SC does not lose contact with past employees but maintains a close contact with them into retirement. Perhaps this is also an indication of - "THE SPIRIT OF STL"


From 1986 to 1991 The abbreviation “STL” was used by STC Technology Limited. In 1991 the takeover by Northern Telecomm of Canada (Nortel) saw the Harlow Laboratories merged with BNR (Bell Northern Research, part of Nortel). Administratively they then became Nortel, then Nortel Networks and again, in 2006, Nortel - plus ça change!

This history kindly contributed by Vi Maile.


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