Engineers were this weekend carrying out emergency works on the Forth Road Bridge’s suspension cables.
The work was scheduled at short notice after an inspection identified new damage to nuts on the bolts that hold the vertical hanger ropes to the bridge’s main suspension cables. The hanger ropes loop around metal castings which are bolted to the cables by 35mm diameter steel bolts, each with a nut at either end. There are 944 of these bolts.
Cracks had previously been found in a small number of the nuts during a routine inspection in 2007. These nuts were replaced and the bridge authority stated its intention to replace all of the nuts over time as and when access and resources permitted.
“We’ve now found cracked nuts at both ends of one of the bolts, which is why we’re bringing forward their replacement,” said chief engineer and bridgemaster Barry Colford.