Dictionary

dropshaft en · NOUN

Etymology

Compound of drop + shaft.

Meanings

1. A vertical shaft which objects can drop through.
   • The water flows from a large suitably fed tank into the dropshaft through a sharp-edged orifice, whose diameter (Do) is 100mm large. 2006, Maurizio Brocchini, Filippo Trivellato, Vorticity and Turbulence Effects in Fluid Structure Interaction, WIT Press, →ISBN, page 161:
   • Melas said that district engineers had located Deep Tunnel dropshafts that were near a portion of the freight tunnels and that they would drill, cut or blast through to the flooded areas "as soon as possible." 1992 April 3, Gary Washburn, “Great Chicago Loop Flood cripples businesses”, in Chicago Tribune, archived from the original on 01 Jan 2023:
   • The downpour led to some dramatic images of stranded motorists and geysers bursting through manhole covers. The spouts are a rare effect which occurs when too much water rushes into a dropshaft and traps air that’s normally vented. 2022 September 12, Patty Wetli, “Chicago Dries Out From Intense Deluge. ‘We Don’t See Rainfall Rates That High’”, in WTTW, archived from the original on 10 Oct 2022:
   • The gigantic drill that began digging the deep-bore tunnel from Ballard to Wallingford in 2021 passed its halfway mark last month, chewing through soil that gets hauled away to a Ballard drop shaft (a vertical hole that reaches down to the tunneling site from street level) in 25-ton train carloads. 2023 January 11, Daniel Beekman, “Seattle’s huge sewage tunnel is halfway drilled. Take a look inside”, in The Seattle Times, archived from the original on 24 Jan 2023:

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