Joints

The traditional bolted joint has generally been replaced by welding.

Traditionally the joints between members are effected using bolts and gusset plates. This means that a considerable amount of fabrication time is involved in the production of a truss. Increasing labour costs have led to the adoption of welded joints with bolting restricted to site connections. Welded joints are also preferred in areas of aesthetic importance.

Splices: Trusses are typically delivered to site in sections, which are spliced using bolted connections.

It can be seen that a truss is often a large structural component. Considerations of size and overall weight for transportation often dictate that they are delivered to site in several pieces. Site splice joints thus become necessary but this should not cause any problems. Site welding is not considered to be as reliable as shop welding and may be expensive. Alternatively, and more commonly, site connections are bolted.

The splicing requirements are largely dictated by limits on component size related to transportation to site.

There are no hard and fast rules for the placing of splices. However, it does make sense to position them where the forces are low. For all but short spans, this is likely to be difficult because the manufacturer will want to provide individual pieces as near to the limit of economically transportable limits. In the case of trusses the most important of these is the requirement for special authorisation for lengths greater than about 18 metres, although similar restrictions apply to width and weight.