^666 



PROCEEDINGS OF SECTION H. 



oenerally contains acetic acid, its use in lubricants has been largely 

 -dispensed with in Queensland. A graphite preparation has been 

 largely used, Avhich seeins to be fairly satisfactory. Water is, of 

 course, generally met -with in sinking shafts, and in some cases acids 

 ■are. associated with it. In wet sinking shafts, and in other shafts in 

 which much water is hoisted, the ropes are often quickly rendered 

 xmsa'fe owing to corrosion. After ropes have been in use for some 

 time they begin to show signs of crystallisation, probably to a con- 

 siderable extent due to vibration, and as a rule it is found that the 

 lower end of the rope becomes brittle first. It frequently happens 

 that a rope has to be subjected to the torsion test several times until 

 it is cut at a point behind the pulley when the cage is at the top of 

 the shaft. A case recently came under my notice at a mine where 

 the engines were kepi, bailing water continuously. Some 300 ft. or 

 400 ft. were kept coiled on the drums, as the bailing was not carried 

 on from the bottom of the sliaft. The engine-driver one day found a 

 great many wires broken in that part of each rope that travelled in 

 the shaft. A few days afterwards he found that the Avires in the 

 ropes coiled on the drums were also badly broken. Not having been 

 much used these wires showed very little flattening or corrosion. 

 These ropes were of simple construction, with a rather high ultimate 

 :sti-ess, and the wires were of a large diameter, becoming brittle 

 ■quickly, as is often the case in this class of rope. In the accom- 

 panying schedule are some particulars of actual rope tests. In order 

 to save space, and not make the list too tedious, the torsions have 

 been averaged, and I am afraid this averaging may convey a wrong 

 impression. It will, I think, be readily conceded that if 27 wires 

 give only 3 to 5 torsions each, and the remaining 9 wires give each 

 25 torsions, then the system of averaging does not convey a correct 

 idea of the condition of the rope. It is occasionally found that when 

 a wire rope has been in use some time its breaking stress is, 

 especially in ropes of simple construction, slightly higher than when 

 tested before being used. Two such instances were met with in com- 

 pound ropes at the No. 1 South Oriental and Glanmire Gold Mine, 

 tested on the 20th November, 1905, and 11th January, 1907. 



This increase in the tensile strength is often accompanied by 

 :a decrease in the torsion test. Again, sometimes, but not often, it 

 has been noticed that ropes of simple construction seem to increase 

 their ultimate stress as they are worked, while the torsion 

 tests give worse results. A case in point is the north rope at the 

 Columbia and Smithfield Gold Mine, included in the schedule. As a 

 rnle, however, there is a steady decline in both the ultimate stress 

 and the results of the torsion test, as instanced by the record of tests 

 of the ropes at the South Glanmire and Monkland Gold Mine. When 

 a rope begins to give bad results in eitlier test, it is not condemned 

 until several tests have been made, and frequently, when the bottom 

 50 ft. or 60 ft. have been cut ofE, better results are obtained, 

 •especially in the torsion test. But if, after cutting off 100 ft. or 

 loO ft., satisfactory results are not obtained, the rope is condemned. 

 Frequently a rope either brittle or corroded gives fair results under 

 the tensile test, and ropes are more frequently condemned for these 

 defects than for any other deficiencies when subjected to the tensile 

 test. 



