12.3.2 Bracing
Bracing is used to give support, rigidity and longitudinal stability to the runway. There are four common methods
of bracing:
External bracing - A mobile supporting structure is said to be externally braced when the runway is given rigidity by a diagonal bracing member positioned from the support to the runway on the outside of the goalpost arrangement.
Internal bracing - A mobile supporting structure is said to be internally braced when the runway is given rigidity by a diagonal bracing member from the support to the runway on the inside of the goalpost structure.
Box bracing - A mobile supporting structure is said to be box braced when the runway is given rigidity by the box-like design of the supports.
Rigid or splice bracing - A mobile supporting structure is said to be rigid or splice braced when the runway is given rigidity by the design of the joint or splice between the supporting member and the runway.
Figure 12.3.2-1 shows examples of external and internal methods of bracing and Figure 12.3.2-2 shows box bracing and rigid or splice bracing.
Figure 12.3.2-1 External and internal brace
Figure 12.3.2-2 Box brace and rigid or splice brace