Just to add to my comment about the Shell braking systems, Maddock goes on to say:
'…the braking systems for each triple, has undergone modification by Shell transport engineers, with the result that these 50 metre 115 tonne, 62 wheel rigs can be stopped in their own length without skid or axle hop when moving at 70 km/hr. ’
Makes me wonder what Buntine’s tankers had done to them when on the Shell bitumin contract. They were triples, non sleepers with 2 drivers in order to do the full journey Darwin to Alice in one go. There was a metal catwalk across the back of the cab with a low rail round it. Not sure if this is what it was intended for, but it was normal for the spare driver to get into his sleeping bag and stretch out on it. This came to an end when one night, due to a roo or a cow suddenly appearing in the headlights, the driver did an emergency stop. He didn’t hit it or lose control into the bush, but, due to the fact that the pair of them had neglected to check the front tank cap lockings, a great lump of molten ashphalt jumped out and landed on that catwalk. Fortunately the 2nd man was in the cab at the time, otherwise we would have been looking at a Pompeii-type situation. And I don’t mean Portsmouth. 