tightlock

Etymology

From tight + lock.

tightlock means A form of Janney coupler, typically used on North American mainline passenger rail cars, having mechanical features that reduce slack in normal operation and prevent telescoping in derailments, yet remain compatible with other Janney types. Lexicurio rates it Sui generis — a strength score of 95 out of 100.

noun

A form of Janney coupler, typically used on North American mainline passenger rail cars, having mechanical features that reduce slack in normal operation and prevent telescoping in derailments, yet remain compatible with other Janney types.