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Tower Technician Glossary
46 terms · the vocabulary of the NWSA exams · each tied to its standard
The NWSA exams assume you know the words. These are the ones that show up — in the Candidate Handbook, in A10.48, in the rigging math, on the tower. Every definition is written to be correct, not just familiar, and names the standard where one applies. Links go to the free practice test where the term is examined.
- 100% tie-off
- Being connected to an approved anchorage at every moment you are off the ground, including transitions. ANSI/ASSP A10.48 requires it for tower climbing; a twin-leg (Y) lanyard is how it is done in practice.
- Anchorage
- The secure point of attachment for a fall-arrest system. Under OSHA 1926.502 it must support 5,000 lb per attached worker or be designed by a qualified person with a 2:1 safety factor.
- Appurtenance
- Anything mounted on a tower that is not the tower itself — antennas, RRUs, mounts, dishes, lines, lighting. Each one adds wind area and weight that the structural analysis must account for.
- ARC
- Advanced Rigging Concepts — the NWSA specialty certification for rigging planning and execution on communication structures. 95 questions, 150 minutes; requires an active TTT-2.
- Azimuth
- An antenna's horizontal pointing direction, in degrees clockwise from true north. Verified with a calibrated instrument, never a phone compass next to steel.
- Basket hitch
- A sling hitch where the sling passes under the load and both ends go to the hook. With vertical legs its capacity is about twice the sling's vertical rating.
- BBU
- Baseband unit — the equipment in the shelter or cabinet that processes calls and data and connects to the RRUs on the tower by fiber.
- Bend radius
- The minimum radius a cable can be bent without permanent damage. Exceeding it on coax crushes the dielectric; the fault shows up on the sweep and the line is replaced.
- Capstan hoist
- A friction hoist: the rope wraps a powered rotating drum and the operator controls the load by tension on the tail. The tail is never wrapped around a hand or body.
- Choker hitch
- A sling hitch that tightens around the load. It reduces the sling's rated capacity, typically to 75–80% of vertical, because of the bend at the choke.
- Competent person
- OSHA's term for someone who can identify existing and predictable hazards and has authority to take prompt corrective action. Different from a qualified person.
- D/d ratio
- The ratio of the diameter of a bend (sheave, pin or load edge) to the diameter of the rope or sling going around it. Small ratios sharply reduce capacity.
- Dorsal D-ring
- The D-ring on the back of a full-body harness between the shoulder blades — the primary attachment point for fall arrest.
- Drip loop
- A downward loop in a cable just before it enters a shelter or cabinet so water drips off the low point instead of following the jacket inside.
- Drop zone
- The marked area beneath a load path or work area where a dropped object would land. Nobody enters it while work is overhead.
- Electrical tilt
- Antenna downtilt set inside the antenna by phase shifting, often adjusted remotely (RET). Added to mechanical tilt to give total tilt.
- Exothermic weld
- A permanent molecular bond for grounding connections (Cadweld is a common brand), made by igniting a thermite mixture in a mold. The standard for below-grade ground connections.
- Fall clearance
- The vertical distance a fall-arrest system needs below the anchorage: free fall plus deceleration plus harness stretch plus the worker's height below the D-ring plus a safety margin.
- Gin pole
- A temporary mast attached to a tower to hoist sections and heavy appurtenances above the tower's top. Its capacity comes from a configuration-specific load chart; the competent rigger inspects it before use.
- Ground kit
- A clamp-and-strap assembly that bonds a transmission line's outer conductor to the tower ground system. Installed at the top and bottom of the vertical run and at the building entry as a minimum.
- Guyed tower
- A slender mast held upright by tensioned guy wires anchored to the ground at several elevations. Guy tension is an engineered, measured value.
- Hoisting grip
- A woven wire-mesh grip that tightens on a cable's jacket when pulled, used to hoist coax and hybrid trunk up a tower without crushing the cable.
- Ice bridge
- The covered horizontal support carrying transmission lines between the tower base and the equipment shelter, shielding them from ice falling off the tower. Not the vertical run — that is the cable ladder.
- JHA
- Job Hazard Analysis — the daily, site-specific review of hazards and controls, signed by every crew member before work starts. Also called a tailboard.
- LOTO
- Lockout/tagout (29 CFR 1910.147) — isolating and locking energy sources before servicing equipment. Each exposed worker applies a personal lock; only that worker removes it.
- Monopole
- A single tapered steel or concrete shaft tower. Smallest footprint; climbed by step bolts or an internal ladder; section joints are flange or slip connections.
- ORP
- Online Remote Proctoring — how every NWSA exam has been delivered since January 2024: on the candidate's own computer with a live proctor.
- PIM
- Passive intermodulation — interference generated where strong RF signals meet a nonlinear junction such as a loose, corroded or dissimilar-metal connection. Found by PIM testing.
- Qualified person
- OSHA's term for someone with the degree, certificate or extensive experience to solve problems relating to a specific subject or work. Different from a competent person.
- RET
- Remote Electrical Tilt — a motorized actuator that changes an antenna's electrical downtilt from the base station or network operations center.
- Rigging plan class
- A10.48's grouping of lifts by load and complexity (Class I–IV), setting the required planning and personnel. A 200-lb appurtenance is Class II; Class IV involves a qualified engineer.
- RRU
- Remote Radio Unit (also RRH, remote radio head) — the radio mounted near the antennas, fed by fiber from the BBU and DC power from the shelter.
- Self-retracting lifeline
- An SRL — a fall-arrest device whose line pays out and retracts with the worker and locks on a fall, arresting in a shorter distance than a shock-absorbing lanyard.
- Self-supporting tower
- A lattice tower that stands on its own braced geometry and foundation without guy wires.
- Shock absorber
- The energy-absorbing element in a lanyard that tears out during arrest to keep force on the body under OSHA's 1,800-lb limit. Its deployment adds to fall clearance.
- Snatch block
- A pulley with a hinged side plate that opens to accept a rope mid-line, used to redirect a load line or build mechanical advantage.
- Suspension trauma
- Loss of consciousness and potentially death from blood pooling in the legs of a motionless suspended worker — possible within minutes, which is why rescue capability must be on site.
- Sweep test
- A frequency-domain test of a transmission line (return loss / VSWR and distance-to-fault) that documents the line meets the carrier's specification after installation.
- Tag line
- A rope attached to a hoisted load and held by a ground worker to control rotation and swing. It never carries load and is never wrapped around the body.
- TIA-222
- ANSI/TIA-222, the structural standard for antenna supporting structures — design, analysis, modification and inspection. The current edition is Revision I (effective January 1, 2024).
- TTT-1
- Telecommunications Tower Technician 1 — NWSA's entry-level certification: 85 questions, 90 minutes, no prerequisite.
- TTT-2
- Telecommunications Tower Technician 2 — NWSA's supervisory-level certification: 100 questions, 120 minutes; requires an active TTT-1.
- Twin-leg lanyard
- A Y-shaped lanyard with two legs so one stays connected while the other is moved to the next anchorage — the tool for 100% tie-off during transitions.
- VSWR
- Voltage standing wave ratio — a measure of how much RF power is reflected back down a line. 1.0:1 is a perfect match; carriers typically require about 1.3:1 to 1.5:1 or better.
- Weatherproofing
- Sealing outdoor RF connectors with the three-layer method: electrical tape, butyl mastic worked in with no voids, then tape again to protect the butyl from UV and abrasion.
- WLL
- Working Load Limit — the maximum load a piece of rigging is rated to carry in service. Breaking strength is typically five times WLL; the margin is never available for use.
Test yourself
Terms are cheap; the exam tests whether you can apply them. The free practice tests cover all five NWSA certifications with explanations that use this vocabulary the way the exam does.
Exam facts on this page are from the NWSA Candidate Handbook, CH REV 10/25. Fees, formats and rules change — the handbook is the authority. NWSA Study Guide is independent and is not affiliated with, endorsed by, or recognized by the National Wireless Safety Alliance.