 The single @-@ arch bridge was rebuilt and was actually finished . It stood for a period of about six weeks before again it collapsed because the new bridge was not balanced , which forced the keystone out , which once again caused the bridge to collapse . In the Theory of Arches and Pontypridd , it states that " the weight of the bridge was either too great on the haunches or too little on the crown . " At this stage Edwards was either encouraged or forced to try again with extra money being provided to cover his losses for the earlier attempts . 
