Elphinstone Builds Versatile Power Pole Trailer for Zinfra
Designed to carry power poles up to 15.5 metres long, Elphinstone Engineering’s new extendable dog trailer for Zinfra can also transport 20-foot containers, transformers and palletised freight — giving the utility operator considerably more flexibility from a single piece of equipment.
power-pole-trailer-expanda-dog.jpg Elphinstone Engineering’s Expanda Dog power pole trailer was developed for Zinfra to carry long poles while also providing the flexibility to transport containers, transformers and palletised freight.
Key Features
- Carries power poles from approximately 6.5 metres to 15.5 metres long
- Extendable two-axle dog trailer with a maximum 9.5-metre wheelbase
- Designed to keep the complete borer-truck combination under 19 metres
- Flat deck can carry 20-foot containers, transformers and palletised freight
- Adjustable padded V-block bolsters suit timber, concrete and composite poles
- Onboard weighing displays front axle, rear axle and total trailer weight
- Air-operated extension locks, EBS braking and provision for rear cameras
Adjustable V-block bolsters with polyurethane pads allow the trailer to carry timber, concrete and composite power poles.
Special-purpose equipment is very good at doing the job it was designed for. The downside is that when that particular job is finished, it can spend a fair bit of its life parked in the yard waiting for the next one.
That was something Zinfra wanted to avoid when it approached Elphinstone Engineering about a new power pole trailer.
The basic requirement was straightforward enough. Zinfra needed to transport power poles up to 15.5 metres long behind one of its borer trucks.
But the company also wanted to get considerably more utilisation from the trailer than it could from a conventional dedicated pole carrier.
The Elphinstone design therefore had to be capable of carrying a 20-foot shipping container, transformers and palletised freight, while still performing its primary role as a long-pole trailer.
There was another important limitation.
When coupled behind the borer truck, the complete combination needed to remain under 19 metres overall length, and the design needed to work with trucks fitted with either front- or rear-mounted cranes.
Fully extended, the Elphinstone Expanda Dog can accommodate power poles up to 15.5 metres long while retaining the flexibility to shorten the trailer for smaller loads.
The result is an extendable two-axle dog trailer built around a flat deck, giving the operator considerably more flexibility than a traditional single-purpose pole trailer.
When retracted, the trailer can carry poles down to approximately 6.5 metres in length. Extended, it can legally accommodate poles up to 15.5 metres long, with a maximum wheelbase of 9.5 metres.
That flexibility means the trailer can be configured to suit the load rather than forcing the operator to take a full-length trailer everywhere, regardless of what is actually being carried.
Pole support is provided by adjustable bolsters incorporating V-blocks. On this particular trailer, the arrangement is configured to carry up to five poles, although the positioning can be altered to suit different pole diameters and load requirements.
The V-blocks are fitted with polyurethane pads, allowing the trailer to handle timber, concrete and composite poles without relying on a single support arrangement for three very different materials.
Load restraint has also been designed around the trailer’s broader role.
The Zinfra unit is fitted with air-operated winches for securing pole loads, although manual winches can also be specified.
Along the side rails, Elphinstone has incorporated provision for ratchet-strap anchor points, allowing palletised freight to be restrained with at least two straps per pallet.
That seemingly simple addition is an important part of the trailer’s multi-purpose philosophy.
Instead of returning from a job as an empty pole trailer, the flat deck can potentially be used to move other equipment and materials required in the field.
A 20-foot shipping container can also be carried and secured to the deck, further increasing the trailer’s usefulness across different jobs.
External load indicators for Elphinstone Expanda Dog onboard weighing system
Knowing What It Weighs
Loading flexibility is only useful if the operator can also manage axle weights, particularly when dealing with equipment such as transformers, containers and varying combinations of power poles.
For that reason, the trailer is equipped with an onboard vehicle weighing system.
The system displays the load on the front axle group, rear axle group and the trailer’s total weight.
External load indicator lights are fitted at each axle position, allowing the operator to stand beside the trailer during loading and watch the load increase without repeatedly returning to a fixed display.
A radio remote readout can also be used by the crane operator, meaning axle and total weights can be monitored while the load is actually being positioned.
It is a practical approach to loading equipment that may vary considerably in both mass and centre of gravity.
Air-operated winches provide load restraint for pole transport, while the rear bolster and flat-deck arrangement form part of the trailer’s multi-purpose design.
Built to Extend
The trailer’s extension system runs on oil-impregnated bushes to allow the chassis to move smoothly when being lengthened or shortened.
Air-operated locks secure the trailer once the required length has been selected.
Elphinstone has also incorporated a rear-mounted control that can apply the trailer brakes while it is being extended or retracted.
That means the trailer can still be safely controlled during the extension process even when the towing vehicle is not equipped with a separate hand control for the trailer brakes.
The braking system itself incorporates EBS, while an accessory cable has been run through the trailer to provide for equipment such as rear-mounted cameras.
Even the drawbar has been designed around the reality that the trailer may work behind different trucks.
Multiple drawbar heights are available, including conventional 875mm and 900mm configurations as well as lower 700mm and 750mm arrangements.
The front towing connection is also bolt-on, allowing different coupling systems to be fitted depending on the towing vehicle.
More Than a Pole Trailer
The new Zinfra trailer joins a range of power pole transport equipment already produced by Elphinstone Engineering.
What makes this particular design interesting, however, is the thinking behind it.
Rather than starting with the idea of building a better pole trailer, the project began by asking how much more work could be extracted from the same piece of equipment.
It still carries the long poles it was originally commissioned to transport.
But when there are no poles to move, it can carry a container, a transformer, palletised equipment or other general freight.
For an operator working across remote and changing job sites, that additional utilisation can be just as valuable as the trailer’s headline carrying capacity.
It is a relatively simple philosophy: if a trailer is going to follow the truck to the job anyway, it may as well be capable of doing more than one job when it gets there.
And in this case, that philosophy has turned what could have been another dedicated power pole trailer into a considerably more versatile piece of equipment.
The Zinfra Expanda Dog is fitted with air-operated winches to secure power pole loads, with manual winches also available depending on the application.