mine

Looking West from Lawlor Hill with the Lawlor Shaft Headframe, Rio Grande Lode, in the foreground. The housing was supplied by Mount Isa Mines for their employees. This was a high grade production ore body and the ore was transferred underground on 4 Level to the haulage shaft to the surface. It was not an air shaft.

Robert Lawlor held the 2.5 hectares (6.2 acres) Crystal Lease at Top Camp on the new Mount Isa field when the government geologist, EC Saint-Smith, inspected the area in September 1923. This lease was consolidated into Mount Isa Mines holdings by the end of 1924 but Lawlor's Shaft remained the major access point to ores in the Rio Grande lode during the exploration and ore proving phase (1925-9). The headframe and ancillary buildings were featured in a photograph in the Queensland Government Mining Journal, 15 August 1929.[1] In 1930 the Rio Grande mine was described as being served by the three-compartment vertical Lawlor Shaft, from which, at a depth of 54.4 metres (178 ft), a crosscut in the hanging wall cuts through the lode of sulphide ore. Diamond drilling had already proved the persistence of the ore to a depth of 305 metres (1,001 ft).[1] It is not known when the Lawlor Shaft stopped operating but the King's Cross area of the settlement developed nearby and would have constrained mining operations. During the Second World War, it was used for copper extraction. Source: en.wikipedia.org/wiki/Mount_Isa_Mine_Early_Infrastructure

Ore Bins under construction. Lawlor Shaft, Rio Grande Orebody. 27th September 1930. This orebody was developed to bring the surface to be dumped into the bins. From these bins a train would take this ore around to a Glory Hole in the Black Star mine and dump the ore down to 4 Level Haulage. Around this time disaster struck the 4 Level Drive due to cutting into a huge aquifer and the water inflow was uncontrollable. The miners were sent elsewhere while the water inrush was being controlled. The miners started out to cut a downhill drive from 4 Level in the Rio Grande to a meet up with the 4 Level Haulage drive from Black Star Mine to No. 1 Ore Shaft, Urquhart Shaft. This made the surface operation at Lawlor Shaft redundant

MOUNT ISA MINES LIMITED. The following progress report has been receded from the Mine Superintendent of Mount Isa Mines Limited for the period ended November 15 :— Lawler Shaft.—Rio Grande lode, 150ft. level: North drive was extended 14ft. 6in, total 103ft, from the main crosscut. Average assay values were 28.5 percent, lead, and 28.7oz. sliver per ton, over a width of 53in., with ore on both sides of the drive South drive was extended 16ft. to a total of 82ft., from the main crosscut, in ore averaging 25.6 percent, lead, and 23oz. silver per ton, over a width of 47in., with ore on both sides of the drive. Diamond drill borehole No. 1 was sunk 57ft., to a total depth of 197ft. below the surface, and cased to 90ft. In hard shale and ironstone. Source: "The Brisbane Currier" 30 Nov 1926 trove.nla.gov.au/newspaper/article/21087400#

The 4000 lb bomb was a "blockbuster", basically a thin-walled barrel of explosives that caused huge blast waves on impact.