DIG:
Spardo:
You beat me to it Dig, I have a similar picture which I was going to post. The late John Maddock, writing in 1988 wrote of Shell’s then preference for the Mack Superliner with a Mack V8 460 driving through a 9-speed Mack box (that raises my eyebrows because, like you, I fully appreciated the quad box’s 20 pulling a triple full of cows!). They were still triples back then, semi + 2 dogs, but with some safety mods to the braking systems I believe. Also each semi was a tri but the unit and dollys were tandems.Yes Spardo we had one superliner with a 9 speed box and one with a 12 speed both engines set at 400hp,the 9 speed was so unreliable and used to seize in 2nd gear, Macks finished up supplying a spare gearbox,the 12 speed never gave a problem similar to the quad box but air shift so only one gear stick and I tried to talk the boss into fitting a 12 speed into the other truck but he said while its still under warranty Macks can pay for it we just keep fitting the spare box,we got quite good at it about 5 hours to do the change.When the Macks started doing the Alice run Shell had the draw bars lengthened on the dollys to 14 feet and what a difference that made to the trailers tracking they hardly jigged about at all very smooth and straight to pull.
Dig
I’m wondering if I have got the wrong end of the stick (no pun intended 
) here, when Maddock says:
‘they have a 9 speed Mack box, preferred to a splitter type transmission because of more favourable fuel economy and better drive axle wear, as well as being less complicated from the drivers’ viewpoint’,
I assumed he meant just that, 9 gears, no more. Hence my indredulity, but it sounds from what you say that they were in fact quad or perhaps triplex boxes, but without the need for a 2nd stick.
If that is so, I am surprised at his lack of clarity because it was from him that I posted many years ago on TN his description of the operation of the quad box with 2 sticks. Certainly ties in with his ‘less complicated’ comment. Juggling 2 sticks at 40 mph on a dirt track road, one at times with the crook of the elbow, is nothing if not …errr, complicated. 