Classification of defects seen in surveys of brick sewers by closed-circuit television.

The 'manual of sewer condition classification' has been published as a training and operating manual for use both by operatives and by engineers. This report is intended as a supplement to the manual. It deals with brick sewer condition classification in more detail than was possible in the manual, discusses some changes that have proved desirable in the light of subsequent experience, and describes a number of difficulties that may be encountered in using the system on site. (Author/publisher)