Determination of the Life to Fracture by Bending of Lead Sheaths on under-Ground Power Cable

As a basis for manhole design and cable training in the manhole for underground power cable, a relation is needed between life to fracture of lead sheaths in accelerated bend tests and life to fracture in daily load cycles in the manholes. The available test results indicate a linear relation between log of frequency of bending cycles and log of life to fracture. Further data from slower bend tests and data on life to fracture of sheaths in service are needed.