So let me "Ask the Pilot"
How many of the convoy had winches, and did anyone get bogged on the dunes?
Presumably when the first vehicle 'flies' up the dune, there is little danger of that vehicle suddenly meeting another going the opposite way at the crest?
I can't recall how many had winches (Jeremy obviously did, as did I). It would have been most. We did have a couple of vehicles get bogged (further up the track, so pics to come and I'll elaborate on that then). In fact, I was tail-end charlie that day, so I was determined not to get stuck - I have some movie of me going over (and the onlookers scattering...!).
Suffice to say getting bogged in sand was not a serious issue. It's really a case of getting the right momentum to carry you over the dune. Th people that got bogged just missed enough 'carry' and got stuck just before the crest only just badly enough that they couldn't crawl over.
That said, there were quite a few times when people got part-way up a dune and ran out of steam. They would call 'backing up', go back down and hit it a bit harder (even Jeremy had to do it one occasion IIRC!). Part of the education was 'reading' the dune and working out what gear and speed to use. Despite what I say about the fun, you didn't want to get totally airborne over a crest!
Getting bogged in mud would be a far more serious matter, requiring a lot of winching. In 2016, which I think I may have mentioned, they had heavy rain just before leaving Wiluna and the shire roads were closed. Jeremy used his experience and judgement to 'escape' Wiluna on a side track but said he did have a lot of winching out of mud on low parts of the CSR until they got N of the wet areas.
It is requested that all vehicles on the track stay open on Ch40, which we all did to start with. After encountering some other traffic, it became evident that the chatter can become a bit confusing so Jeremy switched us over to Ch18 while he monitored Ch40 as well. He would make periodic calls asking if other traffic was in the vicinity and he could alert us of oncoming traffic (which is rare). Mostly, once he made an encounter, either they or we would pull over and let respective vehicles past and we would keep each other updated as we passed the other, known number, of vehicles. Our tail-end charlie would call the all-clear once past the others and let them know our convoy was through.
Courtesy is the byword. Sometimes we might hold a little longer at a well or morning tea stop when Jeremy knew vehicles were coming, or to give any that may have just left time to open up some distance.
As for the possibility of confronting someone head-on at the peak of a dune, that never happened or had much prospect of happening, I guess mainly because of low probability. But that said, Jeremy was always active on Ch40 (he also had a much more powerful CB radio than the rest of us) calling to ask if other travellers were around. He seemed to be able to judge how far away others may be - an advantage of his experience for both us and them. He kept us fully informed from the time of first hearing scratchy chatter - which could have been oncoming or following vehicles. Once he had that worked out, he just kept more specific updates coming.
We negated the possibility of running up the backside of our own vehicles by calling [Callsign] 'clear' after cresting a dune - hence the periodic wait on the 'runway'. Quite a few of the dunes were 'double-headers' and some were even 'triple-headers' where you would drop over into a smaller sub-swale before having to hit the next crest (which may or may not be straight ahead - ie. there may be a turn and then quickly into it again). Jeremy would always give the heads-up for anything like that so we were prepared for it.
It could become quite amusing when we were in a close-packed area of dunes with the radio traffic calling 'clear' constantly but referring to a different dune, given the spread that could develop with our ten vehicles. It was important to listen for the callsign of the vehicle in front of you that day. With the exception of the days on the vehicle rotation I was behind Jeremy, I was always behind John & Maxine so I got to recognise their voices which was helpful as of course the call sign number changed daily.
Jeremy had a sand flag and several of us did as well, but those weren't really needed.
As I say, you learn a lot by going on a tag-along with such an experienced leader. I thought it was money very well spent. I rented the Troopy (not many companies do it for the CSR!). They were good in preparing the vehicle - almost new tyres, full workshop check, winch, radio, EPIRB, fridge, fuel and water drums, tools, camping gear - really quite self-contained. The Troopy may be basic but it's just about bullet-proof.
The Victorian couple that had the other Troopy also rented from the WA base of the company I rented from but they did it one-way to drop-off in Darwin. Because I was coming back to Perth, I added another Engel fridge of my own, and added other bits of my own camping gear and left behind some of what they supplied.