Under what circumstances is it safe to climb a tower without a helper or observer?
When no electrical work is being performed
When no mechanical work is being performed
When the work being done is not more than 20 feet above the ground
Never✓Правильный ответ
Объяснение
Nobody should climb a tower alone, at any height and for any kind of work, because a fall, an equipment failure or a medical problem leaves no one able to summon help. Height and the type of work do not remove that risk.