double-tier partition
A partition which extends two stories in height.
Glossary
double-throw switch
In electric wiring, a switch which can charge the circuit connections by moving the switch blade from one of two
Glossary
double-throw bolt
A door bolt that can be projected beyond its first position, into a second (or fully extended) position to provide
Glossary
double T-beam
A precast concrete member composed of two beams with a common slab across the top.
Glossary
double-swing frame
A doorframe which is prepared to receive a pair of single-acting doors, both of which swing in the same direction.
Glossary
double surface treatment
Two successive treatments applied to a surface, such as asphaltic material followed by a mineral aggregate.
Glossary
double-sunk
Recessed or lowered in two steps, as when a panel is sunk below the surface of a larger panel.