Sand flag, radio antennae mounting on a cab chassis

Yes Flynnie, I agree. To be effective a Sand or Dune Flag should be close to the front of the vehicle (bull bar) and of adequate height but I have not been able to find any "Regulations" re this.

I have observed many flags with long poles but very flexible and consequently bending back at even fairly low vehicle speed. Not only is the flag itself no longer near the front of the vehicle but it is now very much lower. The flag in your profile photo appears to be like that. Of course the driver does not get to see his flag in motion and probably believes it is still high and forward.

The Sandflag Kit sold here on ExplorOz is 4 metres high when mounted and has a rigid telescopic fibreglass pole which does not bend with motion or wind. However you need to remember to lower it before passing under trees etc.

I have tried affixing a flag to my HF antennae but was alarmed at how it bent the antennae back on its spring base when doing a little extra speed in the swales.

Allan

You have just had me rummaging through the debris I brought back from the trip. Found the sandflag and its documentation. Also checked the date of that photo - more later.

I fitted a Black Widow sandflag to my Teampoly Smartbar using the smartbar optional sandflag bracket. When I got the sandflag I looked at fitting it to one of the unused CB antenna type brackets supplied with the smartbar. But they looked like they would flex excessively under the weight and flex of the sandflag assembly. I guess that is why Smartbar have the optional sandflag bracket that uses two mounting points on the bar instead of one (one above the other). Pretty obvious in hindsight but less so at the time. (tip if ordering a smartbar get the sandflag bracket at the same time. Saves hassles later like waiting for it to arrive before heading off on trip)

As you say there is a fair bit of flex in the photo. The reason I picked that as a profile photo is the contrast between the flag and the shadow. Adds a bit of interest. The photo was taken on 7.9.09 on the Rig road on top of a high dune. The wind was pretty strong that day and was bending the flag quite a bit. A little more rigidity in the pole might have been a good thing that day. Still the wind was blowing a lot faster than I was travelling so on a still day there would be a lot less flex.

There is below a photo taken from beside and below the vehicle less than a minute after the profile photo and two from the rear quarter and below vehicle (taken one second apart) soon after. These shows despite the strong gusty wind the flag is still well forward, a long way in front of the headboard for instance. Because I was standing well below the vehicle when taking these photos the apparent height of the flag and the vehicle are reduced (squashed down). I would estimate a height of about 3.8 or 3.9 metres instead of over 4 metres for the side photo. In the photos taken from the far rear quarter you can see a bit of movement and the flag probably drops to about 3.5 metres, maybe a touch less. My vehicle is 2.2 meters to the top of the "rabbit ears". The CB antenna is a fraction higher.

Pretty clear that strong winds cause a drop in the effectiveness of my setup. Still I think it is more than good enough. There is also a sunset photo the next evening showing how high that flag really is.

Image Could Not Be Found

Image Could Not Be Found

Image Could Not Be Found

Image Could Not Be Found

Image Could Not Be Found



As far as regulations, I have no first hand knowledge. I can only quote what was included in the instructions of the Black Widow sandflag I got. It says:

"The Black Widow sand flag is a C.A.M.S compliant sand flag (Australian mining standards). The flag consists of three --- sections----. Generally two sections are enough when mounted to an antennae mount on a bull bar or one to two on a roof rack".

I used all three on the bull bar giving a total height of over 4 metres

"The legal height from flag to ground is set at 3000mm. On a bull bar with two sections the height is reached in most cases"...

I would have more than met the 3 meters with two sections and had a lighter and more rigid setup but I went for the extra height. Everyone else I saw in the desert had done the same. I recognised some other Black Widow setups and no doubt saw some of the ones you refer to. Maybe there were shorter ones but I was looking for them and don't recall ever seeing any.

So I think we agree on put them at the front and put them high like everyone else does! And not too bendy.

Yes Flynnie, we seem to be in agreement.

I got on my soapbox about ineffective sandflags. I have observed some which could probably been seen in the driver's rear vision mirror!

The worry is that they could be coming up the other side of my sandhill!
The other worry is motorcyclists with of course, no sand flags. You could very easily collect a new bonnet ornament. Fortunately, the ones that I have encountered seem to be heading in the same direction as myself.

My other concern is the value of UHF radio to warn of approaching vehicles over sandhills. I have endeavoured to use the UHF but on the rare occasions when I do make contact, neither of us has been able to establish where we are relatively except that we are within radio range whatever that happens to be. I find UHF useful for convoys but a waste of time otherwise.

Allan

No worries about soapbox. I took you points about some sand flags, and maybe mine, as too flexible as being valid and relevant to anyone setting up a sandflag. That is why I checked other photos from the same shoot of my vehicle to get a better idea of how bent it was and that is why I posted them for others to see that they can get a bit bent over. My flag had bent more than I would have liked but was still (I think) within tolerance in strong and gusty winds. A little more rigidity would have been useful, certainly no less.

I have heard people talking about using fishing rods for a sand flag and I would caution that they likely would be way too flexible.

I encountered a few bikes coming at me on both crossings and fortunately they were alert and much more manoeuvrable than me and avoided me. They did not worry me. I was more worried about meeting similar sized vehicles head on on a dune. It nearly happened once. I was reversing down a dune after a failed attempt to cross when another vehicle came over it towards me. He thought I was most courteous giving way to him but the truth is I wasn't, I was just reversing prior to having another go. Likely we would have seen each others flags and avoided a collision but it would have been close.

Like you I found CB useless at the top of dunes to warn oncoming vehicles of my approach. At top of a dune they have too much range and you talk to someone 20 or 40 k away on top of another dune. More effective just to monitor the chatter between vehicles to get an idea of who is nearby.

On another note I don't think vehicles should observe "radio silence" on channel 10 but nor should they just chatter incessantly. Somewhere in between is enough to alert other vehicles without crowding the channel. Looking for some feedback or different opinions on this from others who have done the crossing as it seems one of the few areas where there is conflicting advice.