桁けた下した

noun

headroom; vertical clearance; maximum height

Technical term used in civil engineering, architecture, and transportation to describe the vertical space available under a bridge, beam, or overhead structure. Often measured from the road or water surface to the lowest point of the structure above.

• この橋はしの桁けた下したは4.5メートルです。

  The vertical clearance of this bridge is 4.5 meters.

• 大おお型がたトラックが通とおれるように、桁けた下したを高たかく設せっ計けいした。

  The headroom was designed high so that large trucks can pass.