Highway Drain

A pipe that conveys stormwater runoff from a catchment area street catchbasin to a discharge point.

Hold Down

A hinged or removable assembly that secures the boring machine to the track.

Holiday

Any discontinuity or bare spot in a coated surface.

Hook Rollers

See Hold Down.

Hoop Stress

The circumferential force per unit areas, psi, in the pipe wall due to internal pressure.