Recently inspected another part collapsed crank-up tower – in this case one of the slave cables had broken, allowing the upper two sections to fall until tower hardware caught them.
Was also discussing with local club members another collapsible tower with a “safety” who’s safety-disconnect pull rope had fallen off.
On the inspection I made I was able to use a Manlift, to greatly reduce personal risk of exposure if the tower further telescoped suddenly. I was at great pains to position the lift bucket, the arm and the machine itself to be safe if the tower slipped down further while I was troubleshooting the collapse.
Most crank-up designs are supported by a single cable at each lift. There simply is no redundancy built in.
Fall preventers might aid, but lacking a way to later safely recover from an activated fall protection system the tower would remain dangerous.
Towers left unserviced until their ropes rot off are difficult to assess for safety – as the most at risk portions of the supporting cables will be difficult to inspect, making it anyone’s guess if the tower can be lowered or if the cable will break.
Hardly a risk worth taking.
About the best plan of action for an at-risk tower would be to insert blocking solid enough to support the tower at each section, remembering to secure that blocking so it can’t fall out.
Then using a man-lift take down the antennas, masts, rotors, feed & control lines, before using a small crane to take the tower itself down.
My previous article on crank-up towers is at: Is a Crank-Up Tower Forever? – Crank-Up Tower Safety & Inspections