Shepherd, a quietly spoken and good-natured man, was given to anger only when he saw the name Portakabin thus misused. He was deeply, and perhaps rightly, jealous of the tradename that has announced his portable cabins across the world, from Antarctic bases, Docklands building sites and Falkland Island garrisons to Libyan oilfields and the operating theatres of the Leeds General Infirmary. He liked to set the press right.
Shepherd, who died this week on holiday in the Western Isles at the age of 78, patented his world-famous design in 1961. A building construction veteran (he began work, aged 15, with the family business F. Shepherd and Son, York, in 1933), he had already invented a way of delivering concrete via portable silos carried on the backs of lorries. Prior to the Portasilo, dating from 1953, concrete was bagged up and labourers broke their backs shifting the weighty cargo from lorry to building site.
The Portakabin revolutionised building sites around the world. From the founding of Portakabin Ltd in 1963, site supervisors, visiting architects, engineers, foremen, and even the "lump" could meet, plot, plan, drink tea and shelter inside Shepherd's fire-proof, steel huts. A Portakabin is so designed that a fit person can assemble the building entirely by him- or herself. Even the largest version, some 60ft long and boasting the equivalent floor area of a small family house, can be delivered on the back of a single lorry in flat-pack form.
The Pullman model Porta-kabin that followed in 1983, while not quite as luxurious as its name suggested, was cleverly insulated from extremes of heat and cold, and, unlike many older prefabricated houses, a stranger to condensation. A one-piece roof was strong and weather-proof. The cabins could be stacked up one on top of the other, creating, on certain building sites, intriguing pre-fab skyscrapers. Calls of nature were dealt with by trips to adjacent Portaloos, another Shepherd invention and the saving grace of country fairs, open-air pop concerts and classic-car rallies from Land's End to John O'Groats.
Shepherd's real touch of brilliance was to begin manufacturing the Portakabin across Europe in 1971, when he established Portakabin BV in the Netherlands, despite contrary advice from marketing experts, This was followed by sibling companies in Germany (1974), France (1975), Belgium (1985), Switzerland (1987) and Spain (1988). Today, the Portakabin is the only building of its kind that meets every relevant EC code and regulation. It is made at a total of 37 sites in seven countries.
Although designed originally for use by the construction industry, between 70 and 80 per cent of all Portakabins are used as general-purpose offices. British schoolchildren know them as "temporary" classrooms: underfunded head teachers know their Porta-kabins to be more or less permanent fixtures. Doctors' surgeries are often found in Portakabins, as are operating theatres, lifted into position by crane, for example, at Leeds General Infirmary.
The Portakabin achieved its greatest fame as an active combatant in the Falklands War of 1982, sheltering an air-traffic control centre on Ascension Island as British troops dug in to defend the Falklands from further aggression. Margaret Thatcher had 600 Portakabins dispatched to the South Atlantic islands after the defeat of the Argentinian armed forces for use as a garrison.
The idea of portable buildings was not exactly a new one when Shepherd took out his patent in 1961. Tents and yurts (circular tents covered in felt or skin and used by Mongolian and Turkic nomads) date back millennia. It has long been possible to transport timber-framed houses from site to site. Shepherd's genius was to design a modern lightweight building that could be delivered by lorry and assembled by one person and was suitable for any and every climate. It may not be a thing of beauty like a medieval war tent or Mongolian yurt, but to people working in uncomfortable and extreme circumstances around the world the Portakabin has been something of a godsend.
Shepherd never intended the Portakabin to be a replacement for permanent buildings, although experience of pre-fab concrete housing built at the end of the Second World War in Britain had already proved by 1961 that pre-fabrication had as much and even more staying power than most contemporary low-cost housing. Shepherd was, however, a pioneer of the design-and-build system of fast-track construction so feared and despised by architects. This system, taken up by developers in a hurry at the height of the Thatcher- Lawson boom, effectively cut architects from the building process, asking them only to prepare design drawings. This sped up the building process enormously in Britain, a country which, unlike the United States, was traditionally unable to build at any speed unless, literally, there was a war on. Shepherd pioneered his design-build enterprise in 1957. It was as if the ghost of Henry Ford had shaken up the British construction industry.
British architects responded with a number of pre-fab design systems (most notably, "Clasp", as used, for example, in the construction of York University), but Shepherd had a march on them.
A local worthy, Shepherd was at times a member of York City Council, chairman of the Yorkshire Region Chartered Institute of Building, president of the York and North Yorkshire Chamber of Commerce and founder chairman of the York Visitor and Conference Bureau: he was, in effect, a prime example of a practical man who thought locally (the Portakabin was dreamt up on a wet and windy construction site at the army camp at Catterick), and acted globally.
Donald Welton Shepherd, builder and businessman: born York 18 October 1918; managing director, Shepherd Building Group Ltd 1962-72, deputy chairman 1962-96; chairman and managing director, Portakabin Ltd 1972-96; OBE 1992; married 1948 (one son, one daughter); died off Oban, Argyll 27 March 1997.