What Is A Combination Vehicle

Combination vehicle

A towing vehicle in combination with i or more than trailers or other motor vehicle that is being towed.

Gross mass limits

The combined gross mass of an A-railroad train must not exceed 39 tonnes. The combined gross mass of a B-train must not exceed 39 tonnes, unless it has:

at least 2 motor-driven axles in a tandem or tri axle fix
three motor-driven axles in a tri-axle set up.

The combined gross mass of any other combination of a rigid vehicle and 2 trailers must not exceed 20 tonnes.

Aquiver beam

A pair of short axles in the aforementioned line across the vehicle, each axle being:

mounted with two wheels on it (with each cycle at least 500 millimetres apart beyond the vehicle), and
able to oscillate, that is, ane wheel can rising while the other falls.

Oscillating beam

Overall length

For a rigid vehicle and full trailer combination (including load, but excluding collapsible mirrors), the maximum overall length is 20 metres.

The maximum overall length for a truck and semi-trailer combination (including load, but excluding collapsible mirrors) is 19 metres*.

* A semitrailer with a quad axle set up and two steering axle is express to 18 metres (and must take been first registered before 1 December 2017).

Rear steering axles – heavy trailers

Heavy full trailers, heavy unproblematic trailers and heavy pole trailers must not take rear steering axles.

Heavy semi-trailers that are not function of an A-railroad train or a B-train may accept:

a tandem axle set or tri-beam prepare with or without one steering axle, or
a quad-axle set with one rear steering axle capable of turning in both directions through an angle of at least fifteen degrees, or two steering axles if get-go registered before i Feb 2017. If 2 of the axles are steering axles, these must be either:
- the ii rearmost axles, which must be able to plow in the same management through an angle of at least fifteen degrees, or
- the foremost axle and the rearmost beam, which must be able to turn in contrary directions through an angle of at least 15 degrees.

A quad-axle set must be certified by a heavy vehicle-certifying engineer, or other vehicle inspector or inspecting arrangement specifically approved by Waka Kotahi NZ Transport Bureau, to confirm that the steering axles run across the above requirement.

Rear trailing unit altitude

The distance betwixt the rigid vehicle's indicate of zipper on the first trailer and the rear of the combination, including its load. The maximum distance is xiv.v metres, and information technology applies to all combinations of rigid vehicles and trailers.

Retractable axles – heavy trailers

Heavy trailers may have retractable axles in the rear beam set if:

the retractable beam has automated control to ensure that the axles that remain on the ground stay within the advisable legal mass limits and manufacturer'south limits, and
frontwards distance and rear overhang limits are complied with, both when the axle is on the ground and when it is retracted (note that the position of the rear axis may change depending on whether the axle is retracted or in contact with the footing), and
such retractable axles are certified for compliance with the requirements in both the bullet points above.

Note: you tin only operate a vehicle with an beam in a retracted position if the vehicle is unladen.

Semi-trailers

A trailer where:

office of the weight of the trailer and its load is borne by the towing vehicle, and
the coupling is not behind the rearmost axle of the towing vehicle or, if the towing vehicle is a rigid vehicle and has more than one axle in its rear axle ready, is no more than than 300 millimetres rearward of the rear centrality of the towing vehicle.

Stability of heavy trailers

When laden or unladen, heavy trailers with a gross mass exceeding ten tonnes must have a static coil threshold (SRT) of at to the lowest degree 0.35g (where g is the acceleration due to gravity). SRT measures the stability of the vehicle.

Trailers with a torso height or load height of two.8 metres or more than above ground are too required to be certified that they have an SRT of at to the lowest degree 0.35g.

When the trailer goes for its document of fettle (CoF) inspection, the information from the SRT certificate volition be entered on a new certificate of loading for that vehicle.

Trailer:truck mass ratio – heavy trailers

For a rigid vehicle (truck) towing ane heavy trailer, the ratio of the gross mass of the trailer to the gross mass of the truck at all times must not exceed 1.5.

This combination doesn't apply if the speed of the combination vehicle doesn't exceed 40km/h or if the vehicle is operating under an overweight allow with a vehicle axle alphabetize above 1.i.