Manhole

A structure that allows access to the sewer system.

Manning’s Formula

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.

Manual Inspection

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).

Manual Mechanical Shield

Open shield in which manpower is used to excavate the material but which has some steering capability.

Marsh Funnel Viscosity

A measure of the flow rate of a fluid through a calibrated funnel. A Marsh funnel is typically used to measure drilling fluid and slurry viscosity, in seconds per quart (sec/qt) of fluid. The Marsh funnel viscosity of water is 26 seconds per quart.