Question E0A07:
What is meant by “100% tie-off” regarding tower safety?  

Choices:  
A: All loose ropes and guys secured to a fixed structure  
B: At least one lanyard attached to the tower at all times  
C: All tools secured to the climber’s harness  
D: All circuit breakers feeding power to the tower must be tied closed with tape, cable, or ties    

Correct Answer is  B: At least one lanyard attached to the tower at all times  

“100% tie-off” means continuous fall protection: you are always connected to the structure by at least one lanyard. In practice, climbers use a twin-leg (Y) lanyard so that when moving between attachment points, one leg stays connected while the other is repositioned.

Why the correct answer is correct
- At least one lanyard attached to the tower at all times ensures there is never a moment without fall protection, which is the definition of 100% tie-off.

Why the other choices are incorrect
- All loose ropes and guys secured to a fixed structure: Good housekeeping, but not the definition of 100% tie-off.
- All tools secured to the climber’s harness: That’s tool tethering (preventing dropped objects), not tie-off for fall protection.
- All circuit breakers feeding power to the tower must be tied closed: Unsafe and incorrect. Proper procedure is lockout/tagout (de-energize and lock open), not tying breakers closed.

Useful rules of thumb
- Use a twin-leg lanyard so one leg is always attached before moving the other.
- Keep your anchor point above your D-ring to minimize free-fall distance.
- Typical minimum fall-clearance estimate for a 6 ft shock-absorbing lanyard:
  $$C \approx L + D + H + M$$
  where:
  - $L$ = free-fall length (up to 6 ft),
  - $D$ = deceleration distance (up to 3.5 ft),
  - $H$ = harness/D-ring stretch (~1 ft),
  - $M$ = safety margin (~3 ft).
  Example: $C \approx 6 + 3.5 + 1 + 3 = 13.5$ ft clearance below the anchor.