Wednesday, 12 March 2014

The medieval toolchest: the frame saw

There were different types of saws in use during medieval times, for instance the long two-handed saw in use for construction work. Another saw that is frequently illuminated in manuscripts is the frame saw, or it's specialised form, the bucksaw. This type of saw already was in use during Roman times, and still was being used during the 20th century in Germany and the eastern parts of Europe.



Jesus with his father Joseph at work in his workshop sawing a plank with a fixed frame saw. Other tools visible are a claw-hammer, a broad axe and an adze. 12th century manuscript?


The frame of the saw is build up of three pieces of wood, loosely fitting together in an H-form. The sides of the H-frame could either be straight or curved. The bottom of the H holds the saw blade, while the top has a twisted rope to keep the saw blade under tension, which was secured by a wooden wedge. Early examples of this saw type have the blade riveted in the lower end of the frame. Here sawing was only possible to the maximum depth of the wooden support in the middle of the saw. Later types have the blades inserted in a wooden handle so that the blade could be turned and larger lengths could be sawn. This saw type is mainly found in cabinet makers and joiners shops, as it is a very versatile tool, capable of sawing straight lines as well as curved ones.

 One of the lower glass windows of Chartres cathedral showing a woodworkers workshop (1205-1235). A yellow fixed frame saw is hanging next to a saw. Other tools visible are a plane and a pump drill.

 
 A large frame saw, handled by two carpenters. Detail of the fresco "Preparation of the cross" 
by Agnolo Gaddi (around 1380) in the Santa Croci basilica in Florence, Italy.

Two saws can be seen in this mosaic from 1180 depicting the building of the ark in the Monreale Cathedral in Sicily. The man sitting on the ark is using a frame saw, while on the right two men are using a pit-saw to make planks.  



Left: A turnable frame saw depicted in the Hausbucher of the Mendelschen Zwolfbruderstiftung (1414), Neurenberg, Germany. folio 21r. Right: a turnable frame saw from the manuscript. Boccaccio, Des cas des nobles hommes et femmes malheureux, Mid 15th century. British Library, London, UK. Add. MS 18750, folio 5.

Our frame saw is relatively small and is turnable with a handle where the saw blade is inserted into. The frame, including the handle, is 56 cm long and made of beech. The actual saw blade measures 23.5 cm and was made out of a blade of a modern bandsaw. It has 3 teeth per cm and a blade thickness of 0.5 cm.  The saw can be used both on the pull and push (i.e. by turning the frame). We did have a longer middle support at first, but this made the frame saw less easy to operate. In principle, if you make this saw larger, you might operate it by two men, each at one end of the saw holding the frame (as shown in the Agnolo Gaddi image). One of the other useful features of this saw is that it easily can be taken apart, and made into a small bundle for transport.

Our medieval frame saw made of beech. The handles holding the saw blade were turned. 
The curved sides of the frame were made using a bandsaw and a spoke shave.


Left: Detail of the turnable handle of the frame saw. The saw blade is secured in the handle with a small nail. Right: Rotating the wedge will make the tension of the rope stronger. This will hold the saw blade more straight.

3 comments:

  1. Do you know about the teeth configuration. Were they more like rip or cross grain teeth?

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    1. no I do not know the teeth configuration. You will have to check the saw finds - if they indeed still can show something; they are mostly very corroded. Illuminations and paintings of sawblades are mostly not that reliable.

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  2. The blade is attached to the handles with a small nail? Is that documentable? I can't find any information on how blades were attached. Any help you can give me is appreciated.

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