12 axle trailer with gooseneck coupling

VicRoads has established a new policy in Victoria in regards to operators obtaining a single trip permit to tow a platform trailer using a gooseneck coupling connected to the prime mover, and operating with up to 12 lines of axles on the trailer.

Platform trailers are used to transport indivisible loads, such as power transformers and construction equipment, across the road network. Generally, platform trailers will be deployed when the overall mass of the load exceeds 100 tonnes. The connection between the platform and the prime mover can either be via a drawbar or gooseneck coupling.

Recent advances in heavy vehicle technology, including the use of higher tensile steels and a greater emphasis on computer simulations mean that trailers with gooseneck connections are now far more stable than they were in the past.

Consequently, operators can obtain a single trip permit to tow a platform trailer using a gooseneck coupling connected to a prime mover and operating with up to 12 lines of axles on the trailer on specified routes at specified axle mass limits provided that:

  • the coupling is a height adjustable gooseneck so that the platform can be made level prior to the commencement of travel
  • all axles on the platform trailer load share
  • the trailer does not exceed the operating specifications set by the manufacturers in regard to maximum loads, speed and the amount of row that can be safely connected to the gooseneck connection
  • the laden trailer mass not be towed in excess of 70 km/h
  • the gooseneck/platform configuration is arranged in a three-point connection

Arrangement 1: Three point gooseneck connection

Image of a coupling set up on a platform trailer

  • there is a minimum distance of 6.0 metres between the centre of the last drive axle and the centre of the first trailer axle. This minimises the concentration of mass on bridges with longer distances providing greater potential for travel over structures. This distance requirement also assists in avoiding the possibility of the prime mover being “lifted” by the trailer travelling over a crest
  • if a gooseneck connection has a mass compensating mechanism, it is continually operational and maintains a constant mass on the tandem drive axle group, and that the mass is not more than 18.5 tonnes
  • to assist in maintaining traction towing a laden trailer, the vehicle configuration must be adjusted so as to maintain a minimum of 14.0 tonnes on the tandem drive axle group of the prime mover
  • the loading deck in normal travel mode must be no more than 1.0 metre high
  • the number of prime movers pulling/pushing the trailer must be sufficient that the sum of their Gross Combination Mass (GCM) ratings is equal or greater than the gross mass of the vehicle combination, including the mass of the prime movers
  • where additional prime movers are to be used to pull or push a platform trailer , the permit application must include details of the additional prime movers so that the bridge assessments can include the vehicle masses
  • a standby prime mover accompanies a vehicle combination when the total mass of the primary prime mover and trailer vehicle combination exceeds 150.0 tonnes gross (as of 21 January 2013); and
  • single trip permits are obtained for unladen movements of the trailer.

A tandem-axle dolly, fitted between the prime mover and the gooseneck trailer, may also be used.

Permits can be obtained for travel on specified routes at specified axle mass limits by calling VicRoads (Tel: 03 9881 8702) or the National Heavy Vehicle Regulator (NHVR) (External link).

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