herringbone timbering

herringbone timbering

[′her·iŋ‚bōn ¦tim·bə·riŋ]
(mining engineering)
A method of timber support in a roadway with a weak roof and strong sides, using neither arms nor side uprights; the crossbar is notched into the sides and supported at its center by a bar under it and parallel with the roadway; the bar is supported by struts notched into the sides at about half height.