The Kingpost, being stretched by the weight of the roadway and the outward thrust of the Kingpost braces, is said to be in tension. The chord is in tension as well, supported at the abutments and by the Kingpost and stretched by its own weight and the weight of the roadway. As long as the truss, its joints, and its timber members are strong enough to bear the stresses of compression and tension, the bridge will stand. The carrying capability of the Kingpost truss requires that the angles between the Kingpost braces and the chords not get too small, meaning that a wider stream would require a really tall Kingpost. The maximum practical span for a Kingpost bridge is a little over forty feet.
Longer spans require a more sophisticated truss.
The Queenpost truss, for example.