> I don’t understand why it’s even considered safe to have one of these springs in one’s garage without a solid shield of some sort. The shield is the steel tu

> I don’t understand why it’s even considered safe to have one of these springs in one’s garage without a solid shield of some sort. The shield is the steel tube that runs down the middle of the spring. When the spring breaks, it's got an integral safety containment, similar to the aircraft cable that is often run through extension style springs (which are probably far more dangerous when they break, though less dangerous to service). > I’m honestly not sure why springs are common at all in this application. They're nicely matched to the load profile of the door. As the door is fully closed, the spring is exerting maximum upward force. As sections of the door transition to the horizontal track, the spring is simultaneously relaxing some, meaning it exerts around half the force when the door is halfway up and very little force as the last segment hits the turn in the track. It's a pretty elegant match of mechanism to the load profile.