Why Bleachers Sag
Telescopic bleacher systems will sag after students climb on them, or of their own weight. That’s because downward force in the closed or partially open positions is likely to bend and damage the understructure, causing the bleachers to sag.
See exactly what causes sagging in this video:
Video coming soon
All telescopic bleacher systems work pretty much the same way and use the same kind of mechanism for the retractable structure. While some details of construction may vary from one manufacturer to the next, the basic underlying design has not changed much in the last 70 years.
It should be no surprise that if they all work the same way, they all break down the same way. It’s true. The number #1 cause of operational problems in telescopic bleacher systems is SAGGING
Bleachers that SAG won't operate properly – they won't open and close like they're supposed to.
2 Horse vs 4 Horse
“Horses” refers to the assembly of vertical support columns and other pieces that operate as unit when the bleachers are opened or closed. The horses lock into position when the bleachers are fully opened to provide support for spectators. Learn more: 2 horse vs. 4 horse.