computer recording of defects in sewerage systems observed in closed circuit television surveys

this report relates to a research programme being undertaken jointly by the water research centre (wrc) and the transport and road research laboratory (trrl) and covers a section of the work being carried out by william f rees limited under a trrl sponsored contract to study methods of inspection, maintenance and renovation of sewers. the report describes the investigation carried out into the feasibility of using a computer to record and analyse defects observed when surveying sewers, as a continuation of earlier work on the classification of defects. progress made in the development of a system of computer analysis (crodiss) is described, and possible extensions and wider applications are discussed. results obtained clearly indicate that the information collected on defects in sewerage systems by use of the coding system is capable of computer input/output and could possibly be utilised for sewer record purposes.(a)