The side bracket, that triangular shaped thing that hangs on the side of scaffold legs, is a familiar scaffold component. Side brackets, also known as outriggers, are common to both frame and systems scaffolds. (Outriggers, as used here, should not be confused with the outriggers that are used at the base of scaffold towers to increase the base dimensions.) Side brackets allow for the extension of the scaffold platform beyond the legs, usually by a multiple of plank widths. Another type of extension bracket is the end bracket, used to extend the platform at the end of a scaffold run. When used with frame scaffolds, the side bracket is placed at the leg and is parallel to the frame or bearer. The end bracket is also placed at the leg but is perpendicular to the frame or bearer.
The most frequent users of side brackets are masons. The side bracket’s prime feature allows the mason to raise the level of his platform while the stocking platform remains at one elevation. These brackets are designed to support the mason while he lays the brick or block. Consequently it typically is designed as a support for a light duty platform, a platform that supports workers with no storage of material. The material is stored on the stocking platform behind the mason. Like other scaffold components, side brackets, and end brackets, have a limit to the load that can be supported. Additionally, since these brackets are outside the scaffold leg, they produce a cantilever, or overturning load on the scaffold tower. (This force is also known as a tipping force.) This force must be resisted by the counterbalancing effect of the weight of the scaffold equipment, the weight of the material on the platform, ties to the structure, or a combination of these methods. It should be noted that assuming that the wall will stop the scaffold from falling over is NOT one of the methods for stabilizing the scaffold from the overturning effects of the brackets!
While side and end brackets are very useful components, they are easy to abuse. Dropping the brackets from the top of the scaffold can result in bent components, broken welds, and distorted hooks. Another hazard that must be avoided is overloading the brackets. A common, although absolutely hazardous, use of brackets is for a material stocking platform support. These platforms can normally be seen on the back of the scaffold (away from the wall) where the forklift operator places a pallet of brick or block on the scaffold. This is not good. Besides overloading the brackets, a strong tipping force occurs that must be counterweighted by the scaffold equipment and the workers. Unfortunately, since this is such a common practice many people wonder what can possibly be wrong. Since nothing is breaking, can it be a serious hazard? Well, yes! In fact, it’s so serious that your government has a law prohibiting this practice:
“Brackets used to support cantilevered loads shall be used only to support personnel unless the scaffold has been designed for other loads by a qualified engineer and built to withstand the tipping forces caused by those other loads being placed on the bracket-supported section of the scaffold.” (29 CFR 1926.452( c)(5))
Are there solutions to this situation that solve the hazards of overload and tipping? Yes there are. First, a bracket can be designed and fabricated that will support heavier loads. Scaffold equipment can be secured to the structure with ties properly sized and located as to counteract the tipping forces from the cantilevered loads. The scaffold can be reconfigured or an additional scaffold bay can be added adjacent to the tower run that is purposely used as a loading platform. Your scaffold supplier, the scaffold manufacturer, and qualified engineers, are available to help solve the problem. While the next scaffold you overload may not break, the bracket that you trust your life on may have been damaged. Do you want to take that chance?