Introduction to Health and Safety at Work

Introduction to Health and Safety at Work
174
risk, but are also more likely to inhibit the normal oper -
ation of the machine. In addition, they may in them-
selves create hazards and are likely to be diffi cult and 
hence expensive to maintain.
11.13.1 Fixed 
guards
Fixed guards have the advantage of being simple, 
always in position, diffi cult to remove and almost main-
tenance free. Their disadvantage is that they do not 
always properly prevent access, they are often left off 
by maintenance staff and can create diffi culties for the 
operation of the machine.
A fi xed guard has no moving parts and should, by 
its design, prevent access to the dangerous parts of 
the machinery. It must be of robust construction and 
suffi cient to withstand the stresses of the process and 
environmental conditions. If visibility or free air fl ow (e.g. 
for cooling) are necessary, this must be allowed for in the 
design and construction of the guard. If the guard can be 
opened or removed, this must only be possible with the 
aid of a tool.
An alternative fi 
xed guard is the distance fi xed 
guard, which does not completely enclose a hazard, but 
which reduces access by virtue of its dimensions and 
its distance from the hazard. Where perimeter-fence 
guards are used, the guard must follow the contours of 
the machinery as far as possible, thus minimizing space 
between the guard and the machinery. With this type of 
guard it is important that the safety devices and operating 
systems prevent the machinery being operated with the 
guards closed and someone inside the guard, i.e. in the 
danger area. Figure 11.12 shows a range of fi xed guards 
for some of the examples shown in Figure 11.10.
11.13.2 Adjustable 
guards