Solar That Really Works!

Solar that Really Works! covers the design, installation and use of solar in cabins, camper trailers, caravans, fifth wheelers, campervans and motor homes.

eBook versions

Paperback version

The book retailers set their own prices which can vary substantially. We'll aim to keep a selection of the better prices above.

Any bookshop, whether online or bricks and mortar, can order copies of Solar That Really Works!  Just ask.
ISBN: 978-0-6483190-3-0

The Camper Trailer Book

Fourth Edition

by Collyn Rivers

The Camper Trailer Book was first published in 2006. Camper trailers and usage, however, changed so fast it has been updated several times.

This book has not yet been converted to an eBook format and is not yet available as a paperback. While printed copies of previous editions may still be available, we have decided to publish this new edition of The Camper Trailer Book on this website.

Each week we will add a new section.  Over time the complete book will be available on this site. As each section is added it will also be completely searchable.

If you own or are interested in travelling with a camper trailer you will find this book invaluable.  It covers every issue you are likely to encounter and then some.  We trust you will find this helpful and useful.

The Camper Trailer Book – Chapter 28: Legal Issues

Tare Weight: unladen weight (but includes a nominal amount of fuel if relating to a vehicle).

Aggregate Trailer Mass (ATM): this is the total mass of the laden trailer when carrying the maker’s maximum recommended load. This includes that imposed on the towing vehicle when both vehicle and the trailer are on a level surface. This is sometimes referred to as Aggregate Loaded Mass (ALM).

Gross Trailer Mass (GTM): this is the mass borne by the axle/s of the trailer when carrying its maximum load uniformly distributed over the load bearing area. It is the ATM minus the towbar load.

Gross Vehicle Mass (GVM): this is the Tare Weight of a vehicle (i.e. not a trailer) plus everything you are carrying, including driver, passengers, dog/s, fuel and water.

Gross Combination Mass (GCM): this is the GVM plus ATM. It is the maximum legal on-road weight including that of the loaded trailer.

Mass: In the above, the term mass can be regarded by owners as the same as weight. It does however have a very specific meaning that needs to be used in engineering/legal matters. In effect it is a measure of a body’s resistance to being accelerated.

Weight: for most purposes (non-technical) purposes, weight can be regarded as that which most people think it is. It is however a result of our Earth’s gravitational force attracting another body that has mass.

In space, a mass that has a weight of 10 kg on Earth has zero weight because there are no gravitational forces acting on it. If someone throws that mass at you in space, the impact would hurt almost much as it would on Earth. (It will not be identical as throwing it causes the thrower to be thrust slightly rearward unless firmly supported at the time.)

Legal towing weights

As from December 1998, Australia’s national rules specified, in essence, that a ‘motor vehicle with a Gross Vehicle Mass (GVM) not exceeding 4.5 tonnes must not, without the approval of an authority, tow a trailer with a mass (including any load) exceeding the capacity of the towing apparatus fitted to the vehicle, or the relevant maximum trailer mass specified by the vehicle manufacturer’ – with the overriding rule that such maximum weight is whichever is the lesser of the two.

As every vehicle manufacturer now specifies that maximum towable mass, and tow bar makers specify the maximum loading of their units, the towing weight limit can be readily established.


Brakes are not legally required on single-axle trailers with a GTM not over 750 kg. For the purposes of this ruling, two axles with centres spaced not more than one metre apart are, for the above purpose, regarded as a single axle.

Excepting for the above, all trailers must have an ‘efficient braking system’.

Over-run brakes may be used on trailers up to 2000 kg GTM.

If under 2000 kg GTM, an efficient braking system is considered to have brakes operating on the wheels of at least one axle.

If over 2000 kg GTM the trailer must have brakes operating on all wheels.

Above 2000 kg GTM all brakes must be operable from the driver’s seat of the towing vehicle.


Drawbars must withstand the following forces, applied at the centre line of the intended coupling without detachment, or any distortion or failure that will affect the safe drawing of the towed trailer.

Longitudinal tension and compression (N)1.5 X 9.81 X ATM (kg)
Transverse thrust (N)0.5 X 9.91 X ATM (kg)
Vertical tension and compression (N)0,5 X 9.81 X ATM (kg)

Tow Ball Height

The centre body of the tow ball coupling must be 350 mm – 420 mm from the ground.

Safety chains

All trailers without a breakaway mechanism (that automatically applies the brakes if the trailer breaks away from the towing vehicle) must be fitted with safety chains.

The requirements vary with the ATM but, up to an ATM of 2500 kg, there must be at least one safety chain complying with AS 4177.4-1994, or as amended.

The chain must be permanently attached to the trailer (a shackle is not permitted). Welding is acceptable for this level of ATM.

Dual axles

There are also various requirements many of which depend on whether or not the suspension is load sharing and also of the axle’s fore/aft separation. These are spelled out in detail in VSB-1.

Towing speeds

Legislation governing what size and/or weight trailer can be towed by what weight of vehicle etc. was standardised nationally in December 1998.

The new regulations removed the former speed restriction of 80 km/h for vehicles weighing less than 4.5 tonnes whilst towing trailers having a laden weight over 750 kg.

General speed limits apply. Vehicles over 5.0 tonne, with or without a trailer, are limited to 100 km/h.

The definition of ‘camping’

Authorities define ‘camping’ in various ways but it is the local councils’ health department regulations that usually prohibit overnight occupied parking.

You may get away with it you do not raise a pop-top roof or let stuff drain onto the ground, but it is extremely difficult, and probably impossible, to argue that erecting and using a tent-type camper trailer is ‘not camping’.

Drinking alcohol whilst camped

Section 25 of the Police Offences Act rules it is illegal to drink alcohol in a public place. A public place is any place prescribed by regulation for the purposes of Section 25.

Subsection 25(5) extends Section 25 to make it an offence to drink alcohol in a stationary motor vehicle, which is in a (prescribed) public place.

The intent of this part of the Act is, (from Hansard 10 May 1995), ‘to cover those people who go from hotels to their cars, with liquor, and sit drinking their liquor. Often after consuming the liquor, they return to the hotel, purchase more, and on the way to and fro, damage property and otherwise conduct themselves in an antisocial manner.’

It is technically an offence to consume alcohol in a camping trailer whilst settled down for the night in a (prescribed) public place, but most police officers are aware of and respect the intent of the Act. It is thus unlikely in the extreme that police would take any action in these circumstances. In the improbable event that they did, any consequent charge would almost certainly be thrown out of court.

Fishing licences

Fishing licensing and fishing restrictions vary from state to state and are frequently changed and/or updated. Illegal fishing can (in the NT for example) result in confiscation of all associated equipment. This does not mean just your rod and line – it can extend to your vehicle and trailer.


Even though you plan to be away from home for some length of time, or to spend life more or less permanently on the road, Australian law still requires you to vote.

Pre-registering as an ‘itinerant voter’ enables you to vote from any polling booth. Electoral Offices can assist you in this matter. They are listed under that heading in the Telstra White Pages.

Licences & registration

Some states will renew licences prior to their expiry date and if this option is available, it is worth surrendering a still-current licence as a five-year licence can usually be obtained.

To obtain or renew a driving licence, you must provide a street address (not a PO Box), in the state that is issuing the licence. There is no way around this one – arguments that you have ‘no home state’ will not be accepted. Use a relative’s address if necessary because it is no address – no licence.

Vehicle registration is similar. The authorities demand you have a ‘garage address’. Arguing your Troopy is never ‘garaged’ is a waste of time. You may need to use a relative’s or friend’s address in the state where the vehicle is registered. This address does not need to have a physical garage, nor even a parking space on the street within kilometres. All the authorities actually need is an address in the state in which the vehicle it is registered so that you can be contacted by letter mail.

Before leaving home, contact a registration office in your home state to establish procedures.

Be certain to obtain the authority’s interstate (i.e. full) telephone number and store it somewhere safely because most licensing authorities list only 013 telephone numbers for their own state – and those cannot be accessed from another state. Nor will Directory Enquiries advise a licensing authority’s full number.


This one confuses those who refer to Australian and New Zealand Standards – but are not aware that the words ‘should’ and ‘shall’ have legally defined and quite different meanings.

Should in effect means that whatever it refers to is recommended, but does not have to be followed.

Shall states that whatever it refers to is a mandatory requirement: that is ‘you must do it’.

Collyn Rivers is a semi-retired automobile research engineer.  He is the author of seven books, five of which are about making RVs and solar work optimally.

Solar That Really Works!

Solar that Really Works! covers the design, installation and use of solar in cabins, camper trailers, caravans, fifth wheelers, campervans and motor homes.

eBook versions

Paperback version

The book retailers set their own prices which can vary substantially. We'll aim to keep a selection of the better prices above.

Any bookshop, whether online or bricks and mortar, can order copies of Solar That Really Works!  Just ask.
ISBN: 978-0-6483190-3-0