dropwalls

Noun

dropwall (plural dropwalls)

1. A prefabricated wall that is supported by a framework.
   • Once the surface slope was reduced by adding great walls to the original falls, the chief source of damage was stopped. The increased height of fall thus created has been met by building cross walls 4 ft. to 5 ft. high at distances of 30 ft. to 40 ft below original sills or ogees, now converted...1874, Engineering - Volume 18, page 86
2. A short wall used as a weir or floodgate to control the flow of water.
   • The entire work, with the exception of the upper six feet of the weir dropwall and the superstructure of the head-lock, has been completed1867, Himalaya & C., India, page 4
3. A temporary barrier used to surround troops or protect battlements, often with spikes on the outside to prevent the enemy from scaling it.
   • A dropwall took a direct hit and shuddered.2020, Phil Foglio, Kaja Foglio, Agatha H. and the Siege of Mechanicsburg