A system for attaching a safety chain between a tow vehicle and a trailer, said system including: at least one, but preferably two safety chains permanently attached to the trailer, each safety chain having first and second ends which are interconnected by interlocking chain links, with the first end secured to a releasable attachment for attaching the first end to the tow vehicle; and a locking/unlocking mechanism on each safety chain that is permanently attached to the trailer, and that releasably locks its respective safety chain so that a desired working length of that that safety chain can be provided, where the working length is measured between the locking/unlocking mechanism and the first end. The system provided optimum connection between the tow vehicle and the trailer in the event of a primary decoupling.