The clue is in the name! A chainsaw has two main parts: a saw blade built into a chain, wrapped around a long metal guide bar, and a small, one-cylinder petrol engine (sometimes an electric motor powered by a cord or battery pack). The chain is a bit like a bicycle chain, running around sprockets (gear wheels designed to turn a chain) only with about 30 or so sharp teeth (made from a hardened steel alloy) mounted around it at intervals. Inside the engine, as the piston moves in and out of the cylinder, it pushes a connecting rod that turns a crankshaft. The crankshaft turns gears that are connected (through a centrifugal clutch, explained below) to one of the sprockets on which the chain is mounted—and the chain spins around.
The History of the chainsaw
It was not until the 1920’s that someone invented a proper chainsaw. Three names should be mentioned: Wolf (USA), Westfelt (Sweden) and Stihl (Germany). The latter is the largest and oldest chain saw producer in the world. (founded 1926, annual turnover 2004, 1,6 Mia. Euro). In the beginning the idea was to make heavy forestry work lighter using a machine. This should also lead to an increase in productivity and therefore profit. The main phases in the development of the chainsaw were:
- 1926 Stihl developed the first electro-chainsaw
- 1927 Dolmar developed the first petrol chain saw (source: Dolmar)
- 1950 the first one-man chain saw
- 1964 antivibration system
- 1972 chain brake
- 1982 quickstop (automatic chain brake)
- 1989 Catalyser
- 1991 Automatic start
At the end of the 1920’s the first petrol chainsaws were produced. In the beginning they were 2 men chainsaws. This was due to technical considerations and the similarity to traditional saws. Although the chainsaw made forestry work much easier it took decades for it to establish itself. The main reasons for this were the weight of the machines, their unwieldiness and susceptibility to breaking down, as well as the large amount of energy needed by two people. The first two-man chainsaw weighed over 60 Kilos, but progress was not to be stopped. The aim was to develop a lighter, more powerful saw which could be used by one person.
The first one-man chainsaw was produced in 1950 and it was still quite heavy. In 1959 they weighed about 12 Kg (today chainsaws weigh around 4-5 kg, heavy duty chainsaws between 7 and 9 kg) and soon people were raving: “the one-man chainsaws are taking over the forests and timber yards, will the singing of the saw be replaced by the rattling of chainsaws?” (Niggli). At the end of the 50’s there was a shortage of lumberjacks and the hope was that the chainsaw would make forestry work more attractive for young people. As with the change over from the axe to the saw, the introduction of the chainsaw also had its opponents some of whom only wanted to impose restrictions. For instance, in 1957, it was said that it was not worth while using chainsaws for lugging on pine wood and that a clean cut debranching could only be carried out using an axe. Another example were the sinking piecework rates which came about due to the increased efficiency of the chainsaw and which led to the lumberjacks returning to the use of the hand saw.
