Subpart R is the one place in Part 1926 where trained workers are deliberately allowed a window without fall protection. The window is small and heavily conditioned, and it gets cited when either the training or the conditions are missing.
The baseline. Except as provided in paragraph (a)(3), each employee engaged in steel erection on a walking/working surface with an unprotected side or edge more than 15 feet above a lower level must be protected by guardrail, safety net, personal fall arrest, positioning device or fall restraint systems (29 CFR 1926.760(a)(1)).
Connectors. Each connector must be protected from falls of more than two stories or 30 feet, whichever is less (29 CFR 1926.760(b)(1)), must have completed connector training under 1926.761 (1926.760(b)(2)), and, at heights over 15 and up to 30 feet, must be provided with a personal fall arrest, positioning device or fall restraint system and wear the equipment necessary to be able to tie off — or be provided with other protection under (a)(1) (29 CFR 1926.760(b)(3)). The connector decides when to tie off in that band; the employer does not get to decide not to provide the means.
Controlled decking zones. A CDZ may be established only where metal decking is initially being installed and forms the leading edge, over 15 and up to 30 feet (29 CFR 1926.760(c)). Inside it: leading-edge workers are protected above two stories or 30 feet (1926.760(c)(1)); access is limited to employees engaged in leading-edge work (1926.760(c)(2)); the zone is designated and clearly marked, no more than 90 feet wide and 90 feet deep from any leading edge (1926.760(c)(3)); each worker has completed CDZ training (1926.760(c)(4)); unsecured decking may not exceed 3,000 square feet (1926.760(c)(5)); safety deck attachments are made from the leading edge back to the control line with at least two per panel (1926.760(c)(6)); and final attachments and shear connectors are not done in the CDZ (1926.760(c)(7)).
Equipment. Systems and components must meet the 1926.502 criteria (29 CFR 1926.760(d)(1)); in a fall restraint system either a body belt or a harness may be used (1926.760(d)(2)); perimeter safety cables must meet guardrail criteria (1926.760(d)(3)).
The exceptions exist because tying off while making a connection can itself create a hazard. They are not a general permission for ironworkers to work unprotected, and the training records are what separate the two.