A10.48's rigging hand-signal table and OSHA's crane hand-signal requirements are two different systems, not one signal set used two ways. ANSI/ASSP A10.48-2023 sets a standard hand-signal table specifically for material rigging on the structure itself. OSHA's 29 CFR 1926 Subpart CC, which incorporates the ASME B30.5 signal set, governs signals for crane operations. A worker who's trained on one and assumes it transfers to the other is exactly the gap that causes a signal to be read wrong on a lift where both a crane and structure rigging are happening at once.
Why there are two systems at all
The two signal sets exist because they're solving different communication problems. Structure rigging signals govern communication between a rigger on the tower and ground personnel or a hoist operator, working within the fixed geometry of the structure itself. Crane signals govern communication with a crane operator whose boom, load line, and swing radius move through three-dimensional space in ways a fixed-structure rig never does. The vocabularies overlap in places — both need "stop," both need "raise" and "lower" — but the full tables aren't identical, and treating them as interchangeable is where mistakes happen.
A10.48's structure-rigging signals
NATE's Rigging Training Standard, built around A10.48, teaches the standard hand-signal table specifically for material rigging on communication structures — covering the load-line and tag-line communication a rigger on the tower needs with ground crew or a hoist operator during hoisting operations. This table is part of the "Communications" section of rigging training, alongside the broader requirement that there be one designated signal person and that any crew member can stop a lift regardless of who's supposed to be signaling.
OSHA/ASME crane signals
For any lift involving a crane, OSHA's 29 CFR 1926 Subpart CC applies, and it incorporates the ASME B30.5 standard signal set — the signals most people picture when they think "crane hand signals": the flat-hand stop, the raised-fist boom-up, the specific gestures for swing, extend, and retract. This is a nationally standardized set used across the crane industry generally, not specific to telecom towers, and OSHA requires that anyone signaling a crane operator be qualified to do so.
A worker who's trained on one and assumes it transfers to the other is exactly the gap that causes a signal to be read wrong.
The scenario where this actually matters
Most structure rigging never touches a crane — RTS explicitly excludes external hoisting devices like cranes from its own scope, which is why crane work needs separate training regardless. The risk shows up specifically on jobs that use both: a crane setting a section into place while riggers on the structure handle final positioning with their own rigging. On that job, two different signal vocabularies are active on the same site at the same time, for two different pieces of equipment. If a signal person trained only on structure rigging tries to direct the crane, or a crane signal person's gesture gets misread as a structure-rigging signal by someone on the tower, that's a real communication failure with real consequences — not a technicality.
The fix isn't complicated: keep the signal roles separate and explicit. One designated signal person for the crane, trained specifically on OSHA/ASME crane signals. One designated signal person for structure rigging, trained on the A10.48 table. Neither substitutes for the other, and a pre-lift briefing should say plainly which signals apply to which piece of equipment.
Where each is taught
Our Crane Signal Safety & Hand Signals course covers the OSHA/ASME crane signal set specifically — see crane signal certification for tower crews for more on when that credential is required. Structure-rigging communication, including the A10.48 hand-signal table, is part of our Basic Rigging Principles course and the full Tower Rigging Training Program Kit, built around NATE's RTS and ANSI/ASSP A10.48. That kit is not a NATE certification and not NATE-affiliated.
Running a pre-lift briefing that actually prevents this
Recommended certification
Basic Rigging Principles on Communication Structures
$95 · ~4.5h online · certificate issued same day · valid 2 years
Also read: How to Build a Rigging Training Program for Your Tower Crew · Rigging on Antenna Mounts: When It's Allowed
The single most effective habit for avoiding cross-signal confusion costs nothing and takes two minutes: state explicitly, out loud, during the pre-lift briefing, which signal system applies to which piece of equipment and who's holding which role. "Mike is our crane signal person, trained on ASME B30.5 — he's the only one who signals the operator. Sarah is our structure rigging signal person on the A10.48 table — she coordinates the tag line and load positioning on the tower." That verbal assignment, repeated every time a mixed lift happens (not assumed from the last job), is what actually closes the gap between two trained people and two people who both know exactly which system the other is using.
What NWSA's exams expect on this topic
Both TTT-1 and TTT-2 test hoisting and rigging as a major domain — about 20% and 24% of each exam, respectively — and hand signals appear explicitly in both outlines as a rigging-operations topic. Neither exam distinguishes crane signals from structure signals in its published outline language, which is exactly why field-level clarity about which system applies matters more than exam recall alone once a real mixed-equipment lift is underway.
Frequently asked questions
Are A10.48 rigging signals and OSHA crane signals the same gestures?
No. They're two separate signal tables. A10.48's table covers structure rigging specifically; OSHA/ASME B30.5 covers crane operations. They overlap on a few basic signals like "stop" but aren't the same full vocabulary.
If my crew never uses a crane, do we still need OSHA crane signal training?
Only if a crane is actually part of your scope of work. RTS itself excludes crane rigging from its coverage — if your lifts are entirely structure-rigged, crane signal training isn't part of that requirement, though many crews cross-train anyway for jobs that do involve a crane.
Can one person be the signal person for both the crane and the structure rigging on the same lift?
The standards don't prohibit it outright, but it's a real risk in practice — one person tracking two different signal vocabularies and two pieces of equipment moving independently is exactly the setup where a signal gets misapplied. Keeping the roles separate and explicit is the safer default.
Which standard actually requires a qualified signal person?
OSHA's 29 CFR 1926 Subpart CC requires a qualified signal person for crane operations. A10.48's rigging communications requirements similarly call for a designated signal person for structure rigging, though the qualification path differs since it isn't an OSHA-mandated credential.
What should be in a pre-lift briefing to prevent signal confusion?
At minimum: who's signaling the crane and which standard they're trained on, who's signaling structure rigging and which table they're using, and an explicit statement that any crew member can call a stop regardless of who's officially signaling. Stating this out loud every time — not just assuming it from the last job — is what actually prevents the mix-up in the field.
Sources
- OSHA 29 CFR 1926 Subpart CC — Cranes and Derricks in Construction
- ANSI/ASSP A10.48 — order information — structure-rigging communications requirements (purchase required; paraphrased here, not reproduced)
