Towing and A-frames

Introduction

This section has information on towing and towing with an A-frame. 

Towing a trailer

The capacity of the towing vehicle must be suitable for the trailer to be towed.

Towing vehicles must be registered in the correct registration category to tow a trailer that has an ATM over 4.5 tonnes. 

Contact MVR for further registration information.

Generally, truck manufacturers show the designed towing capacity - which is called the gross combination mass (GCM) limit. This information may also be on the compliance plate or build plate attached to the vehicle.

The laden mass of the trailer in a vehicle combination (not being a road train) comprised of a rigid motor vehicle and a trailer must not exceed the laden mass of the rigid motor vehicle.

The towing attachment must also be suitably rated to meet towing requirements.

Towing with an A-frame

You can tow a vehicle (up to 4.5 tonnes gross vehicle mass) that is connected to the tow bar of another vehicle in the Northern Territory (NT) using a triangular shaped frame commonly known as an A-frame.

You should also check with your vehicle's manufacturer to determine whether the towed vehicle is suitable for A-frame towing – eg: read the advice in the 'Owner's Manual'.

Your A-frame must be designed and marked as being suitable to tow the make and model of the vehicle being towed.

If it isn't designed or marked, the A-frame and its connections will need engineering certification before you can use it.

General rules for towing another vehicle

The driver of a vehicle must not tow another motor vehicle unless it meets all of the following:

  • the driver can control the movement of the towed vehicle
  • the brakes, steering and rear lights including indicators of the towed vehicle are in working order
  • the person who is licensed to drive the towed vehicle is in the driver's seat and is in control of its brakes and steering
  • it is safe to tow the vehicle
  • the towed vehicle must be registered or have a current temporary licence.

Coupling

The coupling must:

  • be designed and constructed with sufficient strength to hold the vehicles together in tow and must comply with the Australian Design Rule 62 - mechanical connections between vehicles
  • allow for an adequate amount of angular movement between the towing and towed vehicles to cater for road undulations and curves
  • maintain a space between the combination not exceeding two metres.

A-frame component

The A-frame component must:

  • be secured to a substantial part of the towed vehicle such as a sub-frame or chassis member - connection to the bumper, suspension or steering components is not allowed unless approved by the manufacturer
  • and be marked with the VIN/chassis numbers of both the towing vehicle and the towed vehicle.

Chains and cables

The A-frame component must be equipped with safety chains/cables.

Towed vehicles with a laden mass up to 2.5 tonnes

You must have at least one safety chain complying with Australian standards.

Towed vehicles with a laden mass over 2.5 tonnes

You must have two safety chains.

Towed vehicles with a laden mass over 3.5 tonnes

You must have steel chains with a minimum 800 MPa breaking stress and conforming to the mechanical properties of Grade T chain according to Australian standards.

If you fit safety cables instead of chains you must comply with Australian standards for steel wire ropes.

Towed vehicle laden mass up to 3500kg

Towed vehicle laden mass
(kg)
Minimum chain link diameter
(mm)
Work load limit
(kg)
Number of chains
(minimum)
Marking
(1.5mm for chain < 8mm)
(2mm for chain ≥ 8mm)
Minimum marking frequency
(link)
0 to 10006.3100014177-104th
Up to 16008160014177-164th
Up to 250010250014177-254th
Up to 350013350024177-354th

Towed vehicle laden mass over 3500kg

Towed vehicle laden mass
(kg)
Minimum chain link diameter
(mm)
Break load limit
(kg)
Number of chains
(minimum)
MarkingMinimum marking frequency
(link)
Up to 4500646072(Manufacturer's Mark), T, 8, 80 or 80020th or 1m

More information

For more information get a copy of V65 Northern Territory requirements for A-frame towing of vehicles PDF (518.5 KB)


Lighting and steering

Lighting requirements

All of the following lights must be fitted to the rear of the towed vehicle and be operational whilst under tow:

  • two amber turn signal lamps
  • two red stop lamps
  • two white reverse lamps
  • one registration plate lamp at the rear of the towed vehicle to illuminate the registration plate
  • two red tail lamps.

These lamps may include the towed vehicle's own lights, or a portable light bar can be fitted to the rear of the towed vehicle.

Steering requirements

The A-frame towing must provide safe and adequate steering control for the towed vehicle and the overall combination of both vehicles.

The vehicle combination must be capable of turning within a 25m diameter circle, measured at the outer wheel track.

When travelling in a straight line on a level surface the towed vehicle must follow the path of the towing vehicle without deviating off-line by any more than 100mm.

It is recommended that the tow ball or hitch position on the towing vehicle is placed as close as possible to the rear axle for greater control of the overall combination.

More information

For more information get a copy of V65 Northern Territory requirements for A-frame towing of vehicles PDF (518.5 KB)


Road transformer exemption

A general exemption has been granted to allow a towed implement – known as a road transformer – to be used on a road or road related area without the need for it to be registered. 

This exemption does not apply to any other towed implement.

A road transformer is a towed implement that provides a quick and easy way to maintain a gravelled road between grader road works. It is made from recycled rail tracks designed without wheels and dragged behind a towing vehicle for removing irregularities in gravelled roads. 

Compulsory third party insurance on the towing vehicle extends to cover the road transformer.

More information

For more information get a copy of V77 General exemption for towed implement - road transformer PDF (696.1 KB)


A-frame tow mass ratio and braking

The unladen mass of the towing vehicle must be 3.5 times the laden mass of an un-braked vehicle being towed.

If you want to use a towing vehicle that is less than 3.5 times the mass, you must have control of the brakes on the towed vehicle. You will need approval from the MVR.

The towing limits specified by the vehicle manufacturer must not be exceeded.

The loaded mass of the towed vehicle must not exceed the towing capacity of any component in the combination, including the A-frame, tow bar, coupling and tow ball.

Loads in towed vehicle

You can tow a vehicle that is carrying a load but you must ensure you follow all of the below:

  • the unladen mass of the towing vehicle must remain greater than 3.5 times the laden mass of the towed vehicle when the vehicle is loaded
  • the loaded mass of the towed vehicle doesn't exceed the capacity of any component in the combination
  • that any load carried in the towed vehicle is placed as low as possible and toward the rear of the vehicle to reduce the load on the front axle.

Braking guide

  Stopping distance when brakes applied at 35km/h Average deceleration rate from any legal speed Peak deceleration rate from any legal speed
Vehicle combination gross mass under 2.5 tonnes 12.5m 3.8m/s2 5.8m/s2
Vehicle combination gross mass 2.5 tonnes or over 16.5m 2.8m/s2 4.4m/s2

The parking brake of the towing vehicle must be able to hold the vehicle combination stationary on a 12% gradient.

More information

For more information get a copy of V65 Northern Territory requirements for A-frame towing of vehicles PDF (518.5 KB)