Cradle

A structure constructed from concrete or masonry that provides structural support to a sewer. It typically surrounds the bottom and sides of a sewer up to the springing line.

Cradle Machine

A boring machine typically carried by another machine that uses winches to advance the casing.

Creep

The dimensional change, with time, of a material under continuously applied stress after the initial elastic deformation.

Crew

The number of persons required for the performance of work at a site as determined by the contractor in response to task difficulty and safety considerations at the time or location of the work.

Critical Sewers

Sewers with the most significant consequences in the event of structural failure.