also, if you're not using a shock absorbing lanyard, the forces created by your fall are tremendous, like 5000 pounds, more if the lanyard is tied off below you. When i tie off to something, I want it to be able to hold my truck. That tower isn't going to hold my truck. And yes, safety belts can hurt you badly. i would definitely recommend a full body harness. Not really that expensive, and if you do fall, you will be glad you spent the money. Just my opinion from 12 years industrial construction