September 1932. In the middle of a worldwide economic crisis Albert Thurnherr decided to take over an electrical installation business in the Neubad district of Basel. Before this he had already manufactured various electro-thermal appliances such as water boilers, hotplates and irons, and had, therefore, already had some business experience. But times were hard, and the general lack of work weighed heavily on the young business man. Thanks to the installation department, Albert Thurnherr managed somehow to keep his head above water. In spite of the situation, he still tried to press ahead with the development of his own products. One of the things introduced at this time was the installation of electric drives for church bells. At the same time he continually expanded the production programme for electric heating applications. The crisis years had hardly been overcome, when new troubles loomed: the imminent threat of the Second World War. Thanks to the untiring efforts of his son, Paul Thurnherr, at the start of the war they had a sizeable production programme. When the authorities began rationing the distribution of cooking gas, thuba hotplates and small boilers sold like hot cakes.
In 1948 the private company Albert Thurnherr was transformed into the family-owned limited company Gebrüder Thurnherr AG. In the course if the years thuba products have become known far beyond the borders of the country. Already in 1955 Paul Thurnherr was issued with the first Swiss certificate for an explosion-protected drum lamp. At the beginning of the seventies the decision was taken to disband the installation department and to concentrate solely on the manufacture of goods. In the mean time, with Peter Thurnherr, the third generation had become involved in the company. With the active support of his father, Paul Thurnherr, he took over the management of the company in 1977. Sadly, Paul Thurnherr died far too early in 1984.
The safety regulations of the Swiss Electrotechnical Association (SEV), «Electrical equipment for use in hazardous areas», have been valid in Switzerland since 1978 and correspond to the regulations in Western Europe. Peter Thurnherr works as an expert in both the national and the international standards committees (TC 31 Electrical equipment for use in hazardous areas).
The son has systematically advanced the work begun by his father. Today explosion protection is responsible 99 per cent of the turnover of the thuba Ltd. Most customers come from the chemical, process engineering and mechanical engineering fields. These companies have a common problem: they work in hazardous areas where gases, vapours and mists can form easily. If an electric spark comes into contact with an explosive mixture, an explosion can occur. The sources for the igniting spark are manifold. Not only do the many electric motors that drive the pumps, ventilators and conveyor systems increase the hazard. Electric heaters that supply the process heat for the production also increase the risk. In the meantime the directive does not only cover areas with an explosive gas atmosphere, but also areas with an explosive atmosphere due to dust. Thus, a new body of standards was established covering all aspects of explosion protection.
After Peter Thurnherr took over complete control of the company in 1990, the organisation was also adjusted: now a holding structure takes account of the current situation and allows an optimal coordination of the customer wishes and the different activities.
«thuba» looked for a niche market in the wide range of electrical equipment and concentrated on customized solutions for the field of explosion protection. With regard to knowledge, the various specialized publications issued by the thuba group every year go to show that small companies can play a leading role. In addition, the company also attaches great importance to a documentation that is as complete possible. «This enables us to gain customer confidence. For us confidence is the most important argument».
Today the thuba group has 36 employees and supplies «customized solutions» for explosion protection throughout the world. The fields covered include power distribution, switch and control combinations, industrial electric heaters, trace heating systems for pipes and tanks, hand and machine lamps, special lamps (fibre-optic system) and installation material. Production is divided between thuba Ltd. und thuba EHB Ltd. Together with our partners, the aim is to be able to offer a comprehensive range of solutions for the complete field of explosion protection.
In 1955 thuba Ltd. manufactured its first explosion-protected device, a drum lamp. In those days national standards applied, and no thought was given to harmonizing the standards or dismantling obstacles to trade. Because the company was already concerned with industrial electric heaters, the addition of explosion-protected heaters to the line was a logical next step in the sixties. Around the time the CENELEC standards were introduced, thermostats and control systems were added to the range.
Guideline directives on explosion protection were first issued by the Council of the European Community in 1975. CENELEC, the European Committee for Electrotechnical Standardization, developed the necessary European standards covering electrical apparatus for use in areas with explosion hazards. In 1980, the CENELEC member countries adopted the standards EN 50014 to EN 50020, which were developed on this basis, for inclusion in their national compilations of standards.
Already at the end of the eighties it started to become apparent that the existing standards would have to be replaced by a new directive. On March 23, 1994 the European Parliament and Council approved the new Directive 94/9/EC for the harmonization of the legal regulations of member states pertaining to devices and protective systems designated for use in areas subject to explosion hazards. On July 1, 2003, following a 7-year transitional period, the directive replaced all existing directives on explosion protection at the European level. A new feature of Directive 94/9/EC was the observation that not only electrical equipment, but also non-electrical equipment could serve as sources of ignition for setting off explosions. It also broke new ground by covering areas at risk of either gas or dust explosions.
In January 2000 the Gazette of the European Communities published a second important directive on the subject of explosion protection: Directive 1999/92/EC dated December 16, 1999 contains the minimum requirements for improving the safety and health of workers potentially at risk from explosive atmospheres. This directive took effect on the same date as Directive 94/9/EG. Together, the two directives embodied the protective measures for areas subject to explosion hazards. As a result, recognition of EC Type Examination Certificates was not only assured in the member states of the EU, but also in Norway and Switzerland.
Increasingly, the «International Electrotechnical Commission IEC» took on the leading role in the development and updating of standards. This ensured that the existing standards were applied and harmonized outside the EU’s geographical boundaries. Taken as a whole, today explosion protection is one of the best-harmonized technical fields of all. Additional support is provided by bilateral agreements between European test laboratories (“notified bodies”), because they collaborate with “Underwriters Laboratories UL” and “Factory Mutual FM” in the USA, the “National Supervision and Inspection Centre for Explosion Protection and Safety of Instrumentation NEPSI” in Shanghai, China, the “Technology Institution of Industrial Safety TIIS” in Tokyo, Japan, the “GOST” in Russia and the “Korea Testing Laboratory KTL”in South Korea.
Our paramount goal was not only to fulfill all requirements of the directive in good time, but also to provide input in the various IEC committees and to support the notified bodies. Though probably the smallest company represented, we are now firmly established in the most important committees.