crutch boom [= boom rest

boom socket [= boom step]

cargo boom {single travelling boom}

allowable shut-off time of fast shut-off valve

fall off [= bear off]

hang off [= stop off]

Off beat takes off

Off-Line Handwritten Chinese Character Recognition (off-line HCCR)

off-line trusted third party (off-STTP)

Off-on-off

one-off write-off

voltage cut off or current cut off

3-boom hydraulic rock drilling jumbo

a baby boom in the last Year of the Dragon

additional bending moment on derrick boom

adjustable boom

Anchor Boom

Articulated Boom

articulated boom platform