Which tie-down chain is now almost exclusively employed both aboard ships and ashore?

The tie-down chains that are now almost exclusively employed both aboard ships and ashore are the TD-1A and TD-1B. These chains are designed to securely hold aircraft or other heavy items in place, preventing movement during transport or in adverse conditions. The TD-1A and TD-1B chains offer specific advantages such as high strength, durability, and ease of use, making them a preferred choice within the Navy and in various environments.

Their design incorporates features that facilitate rapid attachment and detachment while providing the necessary safety margins required during operations. Other tie-down chains, while still in use, may not hold the same level of prevalence or operational compatibility as the TD-1A and TD-1B chains, which is why they are recognized as the standard in current practices. This standardization simplifies training and enhances safety, as personnel are consistently familiar with the same equipment across different settings.