Jo-Bu

Jo-Bu Mekaniske Verksted AS was a Norwegian industrial company founded in 1947 by timber merchant Trygve Johnsen and gunsmith Gunnar Busk. Based first at Fagerstrand on Nesodden and, from 1953, at larger premises in Drøbak, the company developed machinery and tools for forestry and became closely identified with its Jobu chainsaws. Its products were designed for the practical conditions of logging and wood processing, and the company’s engineering development helped establish it as a leading Norwegian chainsaw manufacturer. The first commercial model, the Jo-Bu Senior, was developed by Johnsen and Busk and introduced with an Aspin engine. At 17.5 kilograms, it was designed principally for felling and bucking. Its carburetor required adjustment when the saw was placed on its side, an operational limitation that was addressed only gradually. The Junior, introduced in 1952, represented a major step forward. It used an engine made by Jo-Bu, weighed approximately 10.4 kilograms, and became the company’s most successful model, with around 40,000 units produced. The Tiger, launched in 1960, brought another important technical improvement through a diaphragm carburetor that functioned in different operating positions. Jo-Bu became the market leader in Norway and later exported substantial quantities of chainsaws to European markets and the United States. The brand also offered unusual accessories and adaptations. Among the best-known was a propeller attachment that converted certain Senior and Junior saws into outboard motors. The company also made an auger attachment for the Junior Tiger. These products reflected Jo-Bu’s broader identity as a practical forestry-machinery maker rather than a company focused only on standard chainsaws. The business expanded beyond saws in 1959 by adding Istral of Larvik, a producer of trailers and transport equipment for forestry. During the late 1960s, the founders sought to reduce their direct involvement while Jo-Bu needed additional capital for export expansion. Christiania Spigerverk acquired a majority share in 1967 and installed its own management, while Johnsen and Busk remained involved through board positions and technical consulting. When Christiania Spigerverk merged with Elkem in 1971 to form Elkem Spigerverket, the Jo-Bu group became part of that industrial group. Electrolux acquired Jo-Bu in April 1979 as part of a broader chainsaw-industry consolidation. Electrolux already had interests in Husqvarna, Partner, Jonsered, and Skil, and the acquisition was intended to rationalize production. Jo-Bu chainsaw production in Drøbak was progressively reduced, with employment falling from 185 workers in 1979 to 57 at the beginning of 1982. In January 1982, Electrolux decided to concentrate Norwegian production at its Tunborg facility near Sarpsborg, a former stove factory associated with the Husqvarna acquisition. The Jo-Bu name continued for a period on Swedish-made chainsaws using some components associated with the Norwegian operations. The remaining Norwegian production was later closed, and the brand no longer operates as an independent industrial company.

Jo-Bu Mekaniske Verksted AS was established in 1947 at Fagerstrand on Nesodden by Trygve Johnsen, a timber merchant, and Gunnar Busk, a gunsmith. Their partnership combined forestry knowledge with mechanical and metalworking skills. The company’s principal achievement was the development of chainsaws suited to Norwegian forestry work, although its wider product range also included forestry tools, trailers, and transport equipment. The first saw, the Jo-Bu Senior, was developed by the founders and used an Aspin engine with a float-chamber carburetor. Because the carburetor had to be repositioned when the machine was laid on its side, the saw was relatively demanding to operate. It weighed 17.5 kilograms and was intended for felling and bucking rather than the full range of later forestry tasks. In 1952 Jo-Bu released the Junior. It was substantially lighter, at about 10.4 kilograms, and used an engine manufactured by Jo-Bu. Although it retained the earlier carburetor arrangement, its lower weight and practical design made it highly successful. Approximately 40,000 Juniors were produced. The company moved to larger premises at Sagaveien 13 in Drøbak in 1953, reflecting the growth of the business. The Jo-Bu Tiger, introduced in 1960, marked an important engineering improvement. Its diaphragm carburetor operated in different positions, making the saw more suitable for demanding forestry work. Jo-Bu subsequently sold a range of models and accessories. A distinctive propeller attachment allowed some Senior and Junior saws to be adapted for use as outboard motors, while an auger attachment was produced for the Junior Tiger. Such products demonstrated the company’s emphasis on adaptable machinery for rural and forestry users. Jo-Bu was Norway’s market leader for a period and expanded internationally during the second half of the 1960s and the 1970s. Its chainsaws were exported to several European countries and to the United States. To broaden its industrial base, the Jo-Bu group acquired Istral of Larvik in 1959. Istral manufactured trailers and transport equipment for forestry, extending the group beyond portable cutting equipment. By 1967 the founders wanted to reduce their operating responsibilities, while Jo-Bu required stronger finances to invest in exports. Christiania Spigerverk therefore acquired a majority share and placed its own representatives in daily management. Johnsen and Busk continued to serve on the board and remained technical consultants for new products. After Christiania Spigerverk merged with Elkem in 1971, Jo-Bu became part of Elkem Spigerverket. Electrolux acquired Jo-Bu in April 1979. The buyer already controlled several chainsaw businesses, including Husqvarna, Partner, Jonsered, and Skil in the United States. The stated industrial logic was rationalization and coordination of production. Although employment assurances were reported at the time, the Drøbak workforce declined from 185 people in 1979 to 57 at the beginning of 1982. In January 1982, Electrolux’s board chose to consolidate Norwegian production at the Tunborg facility near Sarpsborg, a former stove factory acquired in connection with Husqvarna. The Jo-Bu name continued for some years on saws made in Sweden, with parts linked to the Norwegian operation. The final Norwegian production later ceased, leaving Jo-Bu as a defunct Norwegian industrial brand rather than an independent manufacturer.

• 1982

  Drøbak production is consolidated

  [1]Jo-Buen.wikipedia.org

  Electrolux decides to move Norwegian production to Tunborg near Sarpsborg.

• 1979

  Electrolux acquisition

  [1]Jo-Buen.wikipedia.org

  Electrolux purchases Jo-Bu and begins integrating its production into a broader chainsaw portfolio.

• 1971

  Jo-Bu becomes part of Elkem Spigerverket

  [1]Jo-Buen.wikipedia.org

  The Jo-Bu group enters the new group formed by the merger of Christiania Spigerverk and Elkem.

• 1967

  Christiania Spigerverk acquires majority control

  [1]Jo-Buen.wikipedia.org

  The industrial company takes a majority stake to strengthen Jo-Bu’s finances and support export growth.

• 1960

  Tiger is introduced

  [1]Jo-Buen.wikipedia.org

  The Tiger model introduces a diaphragm carburetor capable of operating in different positions.

• 1959

  Istral joins the group

  [1]Jo-Buen.wikipedia.org

  The group expands into forestry trailers and transport equipment through Istral of Larvik.

• 1953

  Factory moves to Drøbak

  [1]Jo-Buen.wikipedia.org

  The company relocates to larger premises in Drøbak, in the municipality of Frogn.

• 1952

  Junior reaches the market

  [1]Jo-Buen.wikipedia.org

  The lighter Junior is launched and becomes Jo-Bu’s leading sales success.

• 1948

  Chainsaw production begins

  [1]Jo-Buen.wikipedia.org

  Jo-Bu begins producing chainsaws, starting with the Senior model.

• 1947

  Jo-Bu is founded

  [1]Jo-Buen.wikipedia.org

  Trygve Johnsen and Gunnar Busk establish Jo-Bu Mekaniske Verksted at Fagerstrand on Nesodden.

A practical Norwegian forestry-equipment brand positioned around locally developed, durable chainsaws and specialized tools for logging, transport, and wood processing.

• Chainsaw · 1948

  Jo-Bu Senior

  The Senior was Jo-Bu’s first commercial chainsaw and was developed by founders Trygve Johnsen and Gunnar Busk. It used an Aspin engine and a float-chamber carburetor that required repositioning when the saw was placed on its side. Weighing approximately 17.5 kilograms, it was intended primarily for felling and bucking. A propeller attachment was also offered, allowing the saw to be adapted for outboard-motor use.

• Chainsaw · 1952

  Jo-Bu Junior

  Introduced in 1952, the Junior was lighter than the Senior at approximately 10.4 kilograms and used an engine manufactured by Jo-Bu. It retained the earlier carburetor arrangement but became the company’s strongest commercial success, with around 40,000 units produced. The model could also be paired with a propeller accessory for outboard-motor use.

• Chainsaw · 1960

  Jo-Bu Tiger

  The Tiger, launched in 1960, represented a technical advance over earlier Jo-Bu saws. Its diaphragm carburetor was designed to function regardless of the saw’s operating position, improving usability in forestry work. The Tiger formed part of Jo-Bu’s later product family and helped sustain the brand’s position in the Norwegian market.

• Chainsaw accessory

  Junior Tiger auger

  Jo-Bu produced an auger attachment for the Junior Tiger. It was part of the brand’s broader range of specialized equipment that adapted chainsaw power for tasks beyond conventional cutting.

• Forestry equipment · 1959

  Forestry trailers and transport equipment

  Through the 1959 addition of Istral of Larvik, the Jo-Bu group expanded into trailers and transport equipment intended for forestry operations. These products complemented the company’s chainsaws and broadened its role in the forestry-machinery sector.

• 1982

  Production moves from Drøbak to TunborgStrategy

  Background

  After the Electrolux acquisition, the company reviewed the location of its Norwegian manufacturing operations.

  Action taken

  Electrolux’s board decided to gather Norwegian chainsaw production at the Tunborg factory near Sarpsborg.

  Aftermath

  The Drøbak factory’s manufacturing role ended. The Jo-Bu name continued for a period on Swedish-made chainsaws, but Jo-Bu no longer operated as an independent Norwegian manufacturer.

  Source

• 1979

  Electrolux acquires Jo-Bu for production rationalizationM&A

  Background

  Electrolux already controlled several chainsaw businesses and sought to coordinate and rationalize production across its portfolio.

  Action taken

  Electrolux purchased Jo-Bu in April 1979 and integrated the brand into its wider chainsaw manufacturing structure.

  Aftermath

  Employment at the Drøbak operation declined from 185 workers in 1979 to 57 at the beginning of 1982, followed by a decision to consolidate Norwegian production near Sarpsborg.

  Source

• 1967

  Majority investment by Christiania SpigerverkM&A

  Background

  The founders wanted to reduce their direct involvement, while Jo-Bu needed stronger finances to invest in exports and further development.

  Action taken

  Christiania Spigerverk acquired the majority of Jo-Bu and installed its own personnel in daily management, while the founders retained board and technical-advisory roles.

  Aftermath

  Jo-Bu later became part of Elkem Spigerverket after the 1971 merger between Christiania Spigerverk and Elkem.

  Source

1. 1Jo-Buen.wikipedia.org