JP2851169B

PURPOSE:To prevent the disconnection of the optical fibers in an optical cable by preventing the dirt flowing in a pipeline from hindering water flow without being caught by the optical cable and preventing the elongation of the optical cable by elongation of a coil spring when abnormal tension is applied on the optical cable. CONSTITUTION:The optical cable 15 is passed into the sewerage and drain pipeline 13 within a unit section segmented by impounding inlet chambers 11a, 11b as a pipeline junction container. The optical cable 15 is separated into the coated optical fibers 17 and a tension member 19 in a pipeline port 23. The tension member 19 is tensed by the coil spring 21 and is detained above the pipeline port 23, and the optical cable 15 is laid along the inside surface in the upper half part in the sewerage and drain pipeline 13.