Truss-out scaffolds and drop scaffolds

In cases where an access scaffold cannot be founded on the ground or when it is inconvenient to do so, the scaffold can be supported on a framework fixed to the building and projecting outside it. The framework attached to the building or fixed within it is called the truss-out. The access scaffold fixed to the truss-out is an orthodox scaffold in every respect, except that it is founded on and attached to the truss-out. The access scaffold can also be built downwards below the truss-out, a method of construction sometimes called a drop scaffold.