1975Chambers Dict. of Science & Technology 945Proto set (Mining), Mine rescue equipment, weighing some 18 kg and incorporating an oxygen cylinder, breathing bag, and face mask, used for work in foul underground air.
1977Sunday Times 30 Jan. (Mag. Sect.) 1Proto, The name of a breathing apparatus which filters out toxic gases and supplies its wearer with oxygen in conditions of intense heat and bad air.
1972Mining Survey Oct. 28What is a Proto man? Taking his name from the breathing apparatus — his primary ‘tool’ — he is a highly skilled, self-disciplined member of a team that can be called upon at a moment’s notice night or day, to go underground in an emergency and fight fire or save lives.
1946C.B. JeppeGold Mining on WitwatersrandII. 1811‘Proto’ teams, One or more fully trained Proto teams are maintained on most mines...Proto Team Equipment,...5 sets of Proto rescue apparatus...Canaries in small cages.
1960Rand Daily Mail inJ. Crwys-WilliamsS. Afr. Despatches (1989) 325Nobody knows how many hundred yards of rock and debris separate them from the proto (rescue) teams who are working in two-hour shifts.
1976Citizen 19 Dec. 2Police and mine proto teams were last night digging through the rubble of a five-storey block of flats which collapsed when an earthquake struck Welkom yesterday.
1980Sunday Times 3 Feb. (Mag. Sect.) 5Proto teams went down. Wearing oxygen masks and working round the clock they tried to break through to the men.
1989J. Crwys-WilliamsS. Afr. Despatches 327It was hope..which kept everyone going, from the Proto teams clearing a passage at the rate of two metres every three hours,..to the witchdoctor throwing bones in their midst.
1993E. Prov. Herald 15 May 1Specially trained proto teams are working against the clock in a search for the miners.