What is considered unsafe if a trench box is positioned more than five feet above a pipe?

When a trench box is positioned more than five feet above a pipe, the stability of the trench becomes a significant safety concern. Trench boxes are designed to provide support and prevent soil collapse when workers are excavating. If the box is set too high, the load on the trench walls can increase dramatically, which may lead to instability and possible cave-ins. This is particularly critical in relation to the weight and type of materials being handled, as the pressure exerted by the soil can shift and cause hazardous conditions if the trench box is not properly secured or balanced.

For safety regulations, it is vital that the placement of a trench box takes into account the height relative to the pipe and associated ground conditions. Factors such as the weight and type of materials can contribute to this issue, but primarily, it is the stability of the trench that dictates whether the setup is deemed safe or unsafe. Ensuring strong support and maintaining effective engineering practices are necessary to prevent accidents in these scenarios.