What type of shackle is used to secure a bosun chair when persons are working aloft?

The suitable type of shackle for securing a bosun chair while persons are working aloft is the anchor safety shackle. This type of shackle is designed to provide a secure connection and is specifically constructed to handle the load and stress that can occur when individuals are elevated. The anchor safety shackle has a rounded shape and a secure locking mechanism, ensuring that it will not unintentionally open under load, which is vital for the safety of personnel working at heights.

Other types of shackles, such as pin shackles and double block shackles, may not provide the same safety features or load-bearing capacity required for securing a bosun chair effectively. Additionally, while quick-release shackles offer advantages in rapid disconnection, they may compromise safety when used in situations requiring stability and secure anchoring, such as with a bosun chair. The anchor safety shackle, with its design and intended use, therefore stands out as the best option for this specific application.