To serve in Vietnam was to serve in a hot, humid tropical environment. To serve inside an armoured vehicle during the war was to compound the discomfort of a climate that was very foreign to most Australians. Alternating between an unpleasantly hot dry season and a wet season during which the relative humidity could approach 100 per cent, South Vietnam's climate drained men of energy and demanded high levels of endurance.
For APC crews, the dry season meant operating through a constant haze of dust that penetrated their clothing, permeated their pores and worked its way into their eyes and ears causing conjunctivitis and ear infections. The heat and humidity too could become difficult to bear inside an armoured vehicle that magnified the outside temperature. In the wet season, a different set of problems emerged, not the least of which was the need for vigilance against getting one's vehicle bogged. Rain and damp, however, caused the most obvious and most common problems. Men stayed wet for much of the time and being inside a vehicle made little difference if the hatches were open. Crews whose APC's floors were covered in sandbags for extra protection against mines had also to contend with the extra weight when the sandbags took on water as well as the unpleasant odour of mildew and rot common to tropical environments.
Tank's crews, not surprisingly, experienced similar discomforts. As one Australian engineer put it:
The Centurion tank, … some situations we had to have the hatch down, … even with the armoured personnel carriers you had to be hatched down at different times, looking through periscopes which is very frustrating. Of course heat built up in the tank … and the armoured personnel carrier, gets very hot with weapons going off, cordite, heat of the motor, heat of everything else that's going on all the time. It's very uncomfortable.
[Desmond Kearton, RAEME, Australians at War Film Archive]
As one author on the subject of armour in Vietnam put it:
'it can be a test of human endeavour inside a noisy metal box all day in 40-degree heat, with 80 per cent relative humidity and no one has had a shower for a week.'
[McKay, G., and Nicholas, G., Jungle tracks, Australian armour in Vietnam, Allen and Unwin, Sydney, 2001, p. 37.]
Of course the climate was something that everyone who served in Vietnam had to reckon with. In combat, however, the crews of armoured vehicles and, indeed, infantrymen travelling in APCs faced heavy calibre weapons and the ever present threat of mines whose explosive power could be measured in the tens of kilograms. APCs, with their relatively thin armour, were vulnerable to rocket propelled grenade (RPG) fire as well as recoilless rifles and of course mines and booby traps. Even the more heavily armoured Centurion tanks were at risk should an RPG hit them in the right, or, depending on one's point of view, wrong place. Proving the value of armour on combat operations in Vietnam was not without cost.