ventilation shaft Definition

shaft, manhole, duct, elevator shaft, rescuers, stope, mineshaft, chimney stack, ventilation, winze, underground, stairwell, penstock, trench, cavern, hatchway, adit, manway, ductwork, flue pipe, tunnels, drainpipe, chimney, borehole, underpass, mine, coal mine, miners, scaffolding, crawlspace, intake valve, rockface, coalmine, headrace, girders, roof, firebox, weir, floor joist, crevasse, ledge, pipework, pipe, passageway, manhole cover, dewater, falsework, creek bed, upflow, rubble, overpass, breathing apparatus, staircase, basement, coal seam, ceiling, cofferdam, cave, culvert, conning tower, wreckage, subgrade, gangway, waterline, dumbwaiter, alleyway, colliery, sluice, belfry, travelator, floorboards, freshet, serac, sump, storeys, crews, tramming, skylight, airlock, elevator, airing cupboard, cornice, spire, bedframe, stopcock, conveyer belt, subway station, oxygen mask, vents, trapped, gasholder, hose, steelwork, crane, oculus, firedamp, louvres, drill rig, flue, doorway,