Tubular scaffolds, also name tube and coupler scaffolds, are assembled from three following basic structural components:

1. The uprights, or standards, which rise from the ground or another solid supporting base;

2. The bearer, which supports the work platforms and/or provides transverse horizontal connections between the posts;

3. The runners, which attach to the posts directly below the bearers and provide longitudinal connections along the length of the scaffold.

These three components are usually connected with standard or fixed scaffolding couplers which provide a connection. Diagonal bracing is used to stiffen the structure as necessary, most important in the longitudinal direction. Bracing is generally connected to the posts with “adjustable” or “swivel” couplers which have the facility of adjusting. Diagonal bracing should always be attached to the posts as closely as practical to the “node” points formed by the runner-bearer connections.

Another important structural element is the building tie which connects the scaffold to the wall or structure and is needed to provide rigidity and anchorage of the scaffold in the transverse direction. Scaffolds need to be laterally supported; otherwise, they are unstable because of their height-to-width ratio and have low strength to resist wind and other lateral forces.

APPLICATION:

Tube and coupler scaffolds can be assembled in many different ways because of the flexibility of their assembly dimensions in the horizontal and vertical planes. Tube and coupler scaffolds are more adaptable since they are not restricted by frame width in the transverse direction or by brace length in the longitudinal direction or by frame height in the vertical direction (unlike sectional frame scaffolds which are going to be discussed later in this lesson). Therefore for cases of irregular dimensions and contours, such as churches or old auditoriums, tube, and coupler scaffolds become the preferred option since it makes access to the workplace easier.