Former Inmos Microprocessor Factory

Cadw's description

Location

In Duffryn to the Northeast of Tredegar House across the lake, Newport Vishay is reached via the southwest exit of the Pont Ebbw roundabout. The original building is at northeast corner of the site.

History

Factory building for the fabrication of microprocessors and other silicon chips used in computing, built 1980 to 1982. Designed by Richard Rogers & Partners with structural engineering by Anthony Hunt.

The silicon chip and the microprocessor were both invented in the post-war USA, which dominated their manufacture throughout the 1970s. As their military and civilian uses multiplied the governments of Japan, West Germany and then Britain sought to sponsor the establishment of domestic sources of silicon chips.

Inmos Ltd. was set up in 1978 as a publicly owned chip maker through the National Enterprise Board (NEB) under the Callaghan government. The company’s name was an abbreviation for International Metal Oxide Semiconductor, and it was to operate in both the UK and the USA to encourage technology transfer. At its head were two Americans, Richard Petritz and Paul Schroeder, and one Briton, Iann Barron. The fledgling company established design offices in Bristol, England, and its first factory in Colorado Springs, USA and commissioned Richard Rogers to design its UK factory.

Sir Richard Rogers (1933-2021) was at this time best known for his competition winning designs for the Pompidou Centre in Paris (with Renzo Piano) and the ‘inside out’ headquarters of Lloyds Bank in London. The Inmos factory was another example of High-Tech style structural expressionism with its critical services proudly displayed on the exterior of the building. In 1982 Rogers said of his objective for the Inmos building: ‘The design should allow for maximum flexibility and potential growth and change in order to be able to meet the needs of a new and fast-evolving industry.’ Architecture critic Reyner Banham praised the factory as ‘the first really challenging building of the ‘80s.’ Rogers would go on to receive a RIBA Royal Gold Medal, a Pritzker Prize and the National Eisteddfod Gold Medal for Architecture (for his later work on the Senedd building in Cardiff Bay).

Rogers’ design was originally intended for a hilltop location in Bristol, the first choice of Inmos Ltd. However, the NEB as the owner came under political pressure to build the factory in an area with higher unemployment. When the incoming Thatcher government considered scrapping the whole project the Secretary of State for Wales, Nicholas Edwards, was able to make placing the factory in Newport a condition of the further funding needed to build it, awarded through the British Technology Group. The Prince of Wales officially opened the building on 25 February 1983.

The factory was initially laid out with the production ‘clean rooms’ and loading bays on the east side and ancillary plant rooms, offices and canteens on the west side, separated by a continuous corridor formed by the gaps in the base of the nine spinal towers. Production began in 1982 and in the early years focussed on the IMS2600 64k DRAM memory chip. From 1985 Newport mass produced the innovative transputer microprocessors (beginning with the T212 and T414) for which the Occam programming language was invented.

Inmos was privatized through its sale to Thorn EMI in 1984 and in 1989 was sold on to the Italian and French conglomerate SGS-Thomson. A large extension to the southwest was added in 1997. In the early 21st century when the plant was owned by International Rectifier the east side was converted into further ‘clean rooms’. In 2021 Nexperia, a company partly owned by the Chinese government, bought the factory but in 2022 was ordered to sell it under the National Security and Investment Act 2021, leading to its acquisition by current owners US-headquartered Vishay Intertechnology Inc.

Exterior

The building’s ‘High-Tech’ idiom is characterized by the use of advanced materials, highly organized structure, and sophisticated service equipment, with the building turned inside out to display both the structure and services. An exterior super structure of tubular steel, painted blue, suspends the ceiling of the building and supports the complex roof top services which are mainly concerned with providing air scrubbed of the smallest particles to the ‘clean rooms’ in which silicon chips are prepared.

A spine of nine H-Frame towers each suspends six very thin suspension rods holding up the primary lattice trusses which extend out past the edge of the building envelope where they are anchored by return rods. The primary truss arms extend out from a third of the way up each tower with the upper two thirds cross braced with a double X. Secondary lattice trusses run between the primary trusses in the same direction as the spine. The structural parts are pin-jointed and have a complexly engineered lattice structure. North and south entrances are marked by suspended trusses projecting out from the spine ends (at the south now bracketing the later link corridor).

Service boxes containing air-filtering equipment are placed along the spine between the towers. It was intended that these could be easily lifted off by crane for upgrading and none of the original 1982 boxes now remain. Similarly, the pipework visible sprawling over the flat roof has been continuously altered, although the general colour scheme of silver grey for air services and yellow for acidic gas (plus blue for structural elements) has persisted. A steel grid walkway circulates to either side of the spine, below which is a continuous clerestory on either side, sloping down at forty-five degrees from the central spine to the flat roof of the wings.

The curtain walls of the building envelope are an aluminium grid holding removable thin square panels. Originally these were uniformly silver grey on the west production side, with a chequerboard of silver and glazing on the east offices side. With changing use there is now very little glazing and a chequerboard appearance throughout with lighter and darker panels. The Northeast four bays have slightly longer primary truss arms of 35 rather than 30 squares as measured by the envelope grid. The southernmost of these was originally left open for a small garden area long since filled in. Small lean-to additions added since construction reproduce the original square grid, as does a small cube added at the southeast corner.

Interior

The practical purpose of the elaborate roof structure is to maximise the amount of open internal space uninterrupted by columns or load bearing walls. To either side of the line of spine towers is a covered area roughly 106 by 36 metres. At time of inspection the west side where production was originally concentrated was all open space used for storage, with steel posts to the north marking the location of the original clean rooms and construction block walls to the south screening off the original loading bays which are still in use. On the east side, originally offices later turned over to production, the lower southern third contains modern clean rooms partitioned off from the open storage space further north. The outward square grid is expressed internally on the curtain wall with vertical bay dividers punched with circular holes adding to the building’s Meccano-like aesthetic.

Originally the open spaces in the lower thirds of the spine towers formed a continuous seven-metre-wide corridor down the length of the building, bracketed by the portal framed tower bases. These interior portions of the spine towers are tripodal with two large inner cylindrical columns and a smaller outer column which turns inwards 45 degrees as it meets the clerestory glazing. Zig zag lattice tubular cross bracing between these members. This corridor is now interrupted a third of the way north by a changing room and airlock to the current clean rooms, beyond which the sides of the corridor have been opened up. The clerestory is unaltered though black out film has been applied to much of it to block natural light from reaching the later period clean rooms. Clerestory consists of slightly wider than square panes vertically divided by steel bracketing punched with circular holes as i. Overhead services running the length of the spine corridor have been retained and added to, the three large green water pipes are original.

Reason for designation

The Former Inmos Microprocessor Factory is a particularly important building of more than special interest and is listed at Grade II* for the following principal reasons:

Architectural Interest
Of importance to Wales for its architectural design as a key example of a manufacturing building from the latter post-war era and as the most important example of the British High-Tech style of Late Modernist architecture in Wales, by two of its originators Richard Rogers and Anthony Hunt. The building clearly articulates the essential characteristics of this style:

• Design for flexibility - The suspended ceiling provides large interior spaces either side of the spine free from any columns or load bearing walls, while the removable service boxes between the spine towers and exposed pipework on the roof allow for regular upgrading and reorganisation. The square grid walls also allow for removal and replacement of individual panels as the production within evolves.

• Expressed construction and services - The primary structural elements of the Inmos factory are its latticework towers, suspension rods and trusses and most of these are displayed as an exoskeleton. Services are also proudly expressed in the open roofscape. Although these services must change periodically the building’s aesthetic merit is preserved by maintaining a colour scheme of blue for superstructure, silver for air purification and industry standard yellow for acidic gas.

• Technological innovation and lightweight construction – The building used novel materials, technology and design solutions to enhance the prestige of the advanced manufacturing within. An innovative suspended ceiling delivers both the flexible interior and a framework on which to mount services. The factory is principally constructed from a highly complex latticework of tubular steel, a result of close collaboration between Rogers and Hunt as architect and engineer. The walls and ceilings are also thin and lightweight.

Historic Interest
The building clearly illustrates an important aspect of the economic history of Wales in the 1980s as it is the origin point of the modern Welsh semiconductor industry. More generally it is a late example of post-war UK government efforts to seed new manufacturing in Wales to mitigate the decline of Victorian heavy industries. Close Historical association with Inmos Ltd., the UK government’s controversial tech startup which began the Welsh semiconductor industry. The square grid of the factory walls resembles the company logo.

The 1997 extension, including the link corridor, and the smaller satellite structures and connecting overhead services are not of special interest.