Which type of safeties are specified for hand elevators?

Hand elevators are typically specified to utilize instantaneous safeties for a few key reasons related to their operation and safety protocols. Instantaneous safeties act immediately in response to an unsafe condition, such as excessive speed or a sudden drop. This characteristic is crucial for hand-operated elevators, where the user may have less control over the mechanics and the forces involved in operation.

Since these elevators are manually operated, it's essential that their safety mechanisms are reliable and provide an immediate response to prevent accidents. The instantaneous safeties engage as soon as a fault is detected, ensuring that any potential hazards are mitigated without delay. This distinction is particularly important in hand elevators due to their reliance on human operation, where the risk for user error can be higher.

Other types of safeties, like graduated, automatic, or delayed, do not provide the same immediacy of response. Graduated safeties might engage under specific, gradual conditions rather than instantly. Automatic safeties typically refer to more complex systems and are less suited to the manual nature of hand-operated elevators. Delayed safeties can allow for a lapse in time before engaging, which poses a risk that is unacceptable in scenarios requiring prompt safety measures. Thus, instantaneous safeties uniquely fit