Open Face Shield

Shield in which manual excavation is carried out from within a steel tube at the front of a pipe jack.

Open-Face

Term referring to one mode of operation of a traditional TBM.

Operator Presence Control

A control or mechanism designed so that operator presence is necessary to activate a specific function.

Orangeburg

Orangeburg is a bituminized fiber pipe. Manufactured as an alternative to metal pipe in response to a metal shortage due to World War II. The life expectancy from experience is about 25 years. This type of pipe has been known to collapse often necessitating replacement.

Organic Debris

Production waste and other material that accumulates in sewers or manholes.