The great caravan weigh in

And here begins a topic that can certainly do your head in big time … caravan weights. There’s a ton of acronyms to go with the weighing jargon. There’s ATM, GTM, GVM, TBM, GCM and BTC. It’s very confusing.

We just knew that we needed an expert to help us out and make sure we knew what our actual weights were, to ensure we were compliant and safe.

So, Ric from vanweigh.com.au was booked to professionally weigh both my van and my folks van. Thank Peter for organising! And so began the great caravan weigh in. It was great for us! A great learning experience.

Ric first had some heavy duty scales set out under each of the car wheels. With this reading, the gross vehicle mass (GVM) and each axle mass was determined and then could be compared with the compliance plate GVM. We came in with extra to spare but add in all the kids and it’s tight, possibly need to either strap a kid to the bonnet and loose the heaviest one!

Peter’s result will result in a costly upgrade and a serious decluttering. This news was a bit heart breaking for him. Despite the news, this exercise was seriously very valuable! In Ric’s words, it’s peace of mind.

Then it was the caravans turn to get correctly weighed. The van was manoeuvred to sit over the scales so that gross trailer mass (GTM) could be determined. The GTM is the weight of the laden caravan when it is coupled to the tow vehicle. Each axle of the van is also measured. Now understanding the Gross vehicle mass (GVM) and the Caravan’s Gross Trailer Mass (GTM), the Gross Combined Mass (GCM) can be worked out. It’s essentially the GVM (including the tow ball mass) and the GTM combined. This can then be compared with the GCM compliance plate number.

After this the van was unhitched so that the tow ball mass (TBM) can be determined. This is the weight that would be placed upon the tow vehicle when coupling a caravan. We were advised that you only need to have ideally 8 – 10% spare tow ball mass.

I had previously bought a tow ball weight scale and Ric also tested its accuracy. There was a 40kg difference to the precise professional tow ball weight machine. I wasn’t too happy about that. Spent a little more on the Hayman Reese tow ball weight scale clearly with no benefit. 

Here is a little diagram to recap:

Once all the various weights are determined specific to each van, a report is printed and Ric takes you through all the data. He is very helpful and answers each and every question you have.

Ric also sends through a pdf of the document so we have it in digital format for future reference. We had a good result overall and learnt about where we should add any extra weight to balance out  our van. It was also recommended for our situation that we do use a weight distribution system to balance out the weight in our towing vehicle (given that our van was bottom heavy). Peter was advised that it wasn’t necessary for his van and towing vehicle situation.

With understanding the weight distribution over the axles, you can more accurately pack your van to keep safe on the roads (avoiding dangerous sway).

For our Jayco Expanda we need to put heavier items over the right rear axle and lighter items over the left rear axle. This would be because we have the fridge, bunks and cupboards on that size which makes it slightly heavier. Ric did say that the kitchen side can tend to be heavier (if you have your kitchen all to one side). 

Another great bit of information was the option of seeking out a licensing centre where they may be about to match the caravan’s ATM compliance rating to the compliance axle group mass. In our case, it would mean there would be an extra 311kg of weigh that would then meet compliance as opposed to only having 151kg of spare capacity. It didn’t sound like a costly exercise so is something we will check out in the future. 

Now it was helpful for me to see some visuals of all the terminology as well as watching a video. Here is the terminology in chart format:

I also watched a ton of videos on this topic and have listed a collection of videos that you may find useful. The first video includes some explanation on the technical terms. It also includes other safety requirements such as safety chains, mirrors and a great list of questions to think about in relation to insurance. If you would like the list of insurance questions in a pdf, you can go to Caravan Insurance Q’s and download for FREE. 

After a ton of research, I purchased the Falcon Milenco Towing Mirrors. They were highly recommended, economical, are super easy to use and have worked well for our towing endeavours. Peter purchased the Falcon Milenco Grand Aero Convex mirrors which have a different shape.

This next video, by RVSafe, is on caravan sway to help understand why correct weight distribution is essential to a safe traveling experience. It’s a slightly amusing but useful video. 

And last but not least, a little sway demonstration model I also found quite useful.

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