Guards, adjustable/fixed

The whole of the blade except that part that runs downwards from the top wheel to the table should have a fixed guard, with an adjustable guard arranged to cover the exposed part of the blade above the material being cut. 

Adjustable guards comprise a fixed guard with adjustable elements that the setter or operator has to position to suit the job being worked on. They are widely used for woodworking and toolroom machines. Where adjustable guards are used, the operators should be fully trained in how to adjust them so that full protection can be obtained. 

Use of simple safeguarding devices fixed and adjustable interlocked guards trip devices... 

When fixed or adjustable guarding is impractical, an interlocked device should be considered. The interlocked guard provides access to the danger area when the moving parts of the machinery come to rest. The guard is required to ... 

These are fixed or moveable guards, which are adjustable for a particular operation during which they remain fixed. They are particularly used with machine tools where some access to the dangerous part is required (e.g. drills, circular saws, milling machines) and where the clearance required will vary (e.g. with the size of the cutter in use on a horizontal milling machine or with the size of the timber being sawn on a circular saw bench). 

The spindle should be guarded by an adjustable guard, which is fixed in position during the work. 

Adjustable guards comprise a fixed guard wilh adjustable elements that the setter or operator has to position to suit the job being worked on. They... 

We can only specify the work in detail for situations that we understand completely, but there are very few of those. Because we cannot specify work in detail for the rest, human performance variability is indispensable. There are, in fact, only very few situations where performance adjustments are not required, even if every effort is made to establish an isolated and fixed work environment, for instance sterile rooms in neonatal intensive care units, or ultra-clean rooms in a unit where electronic chips are manufacturered. Even in a strictly regulated military operation such as the changing of the guard in front of a royal palace, the soldiers will have to adjust to wind, weather and intrepid tourists. The more complicated or less tractable a work situation, the greater the uncertainty about details and the greater the need for performance adjustments. (That is, more will be left to human experience and competence, and less to the capabilities of technological artefacts.)... 

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