Describes any trenchless technology process which requires an operative to enter a pipe, duct or bore. OSHAOccupational Safety and Health Administration has no minimum size limit for Man-Entry; however, they address a much broader concept of “confined space” in Title 29 Code of Federal Regulations Part 1910.146. The minimum size for which this is permissible in the UK is 900 mm (approximately 36 in.).
A structure that allows access to the sewer system.
An equation for the value of coefficient c in the Chezy Formula, the factors of which are the hydraulic radius and a coefficient of roughness; an equation itself used to calculate flows in gravity channels and conduits.
Method of sewer inspection that usually involves physical entry and hands-on examination; also includes used of CCTVClosed circuit television used to carry out internal inspection and survey of pipelines. camera with manual puppetting (e.g., in manholes).
Open shield in which manpower is used to excavate the material but which has some steering capability.