Lock.

(13) Lock. A device that utilizes a positive means, either a key or combination lock, to hold an energy-isolating device in a safe position that prevents the release of energy and the startup or energization of the machinery, equipment, or system to be serviced.

Source

29 CFR § 1915.80

Scoping language

The provisions of this subpart apply to general working conditions in shipyard employment, including work on vessels, on vessel sections, and at landside operations, regardless of geographic location.