What is the third class of types of safeguards, along with fixed and interlocking guards?

The third class of types of safeguards, alongside fixed and interlocking guards, is automatic guards. Automatic guards are designed to move into place without the need for manual intervention, providing a protective barrier during potentially dangerous operations. They often work in conjunction with other safety measures to enhance worker protection by ensuring that hazards are effectively mitigated when machines are in use.

In the context of safety, automatic guards are important because they can react quickly to changing conditions, unlike manual guards which require human operation. This reduces the risk of human error and ensures that protection is consistently provided when needed. By utilizing automatic guards, organizations can create a safer working environment, thereby minimizing the chances of accidents and injuries associated with machinery.

The other options refer to various types of guard mechanisms but do not fit the classification alongside fixed and interlocking guards as well as automatic guards do in terms of their operation and safety functions.