Delivering lightweight ultra quads with SAF-Holland

Duraquip banked on SAF-Holland axles and suspension to produce a fleet of lightweight long haul ultra quad side tippers for heavy haulage application in Western Australia.

Heavy-duty transport vehicle and equipment manufacturer, Duraquip, has delivered a number of ultra quad combinations for David Campbell Transport (DCT) recently. The new lightweight long haul ultra quad side-tipper fleet is an addition to DCT’s existing fleet that is in use for its mining operations in the Pilbara region in northern WA.

Duraquip specialises in heavy-duty transport solutions for the mining, agricultural, industrial, and earthmoving sectors across Australia. For the past 15 years its portfolio has included off-road floats, dollies, trailers, liquid tankers and side-tippers for logistics and material handling applications. However, this order marks Duraquip’s move into the iron ore ultra quad market.

Mining applications can be as tough as it can get and demand rugged units that tick all the right boxes on the efficiency, safety and durability list. But one of the requisites on this order from DCT was to make lightweight units that deliver better performance standard for multi-combinations. So, when it came to choosing the axles and suspension, Duraquip recommended going with SAF-Holland.

“It’s a lightweight suspension but to be able to get these trailers to do the job you would need to meet certain performance criteria, so a fairly stringent Performance-Based Standard (PBS) assessment was required, and the SAF-Holland product met the performance requirement in the PBS modelling,” says Tony Richardson, Duraquip’s design and sales support manager for Perth metro division.

The new ultra-quad combinations feature a tri-axle group on the lead trailer and quad axles including a rear self-steering SAF axle on the following three trailers to ensure an acceptable swept path on turns. The SAF self-steering axle has a weight capacity of nine tonnes and an additional weight of 136kg in comparison with the corresponding rigid axle.

The SAF steering axle results in less tyre wear, lower fuel consumption, a high level of driving comfort, optimal manoeuvrability due to precise tracking and a higher resale value of the trailer. Meanwhile, the SAF rear steer axles enables the ultra-quad axle trailers to track exceptionally well both on straight highway stretches and around the corners.

The stabilisation damper provides weight optimised steering stabilisation to improve handling on straight and winding roads. The stabilisation damper is suspended on the axle body on one side and on the steering tie rod on the other. It is either pressed (shortened) or pulled (lengthened) depending on the direction of the steering knuckles’ movement. The unique design of this damper means that its internal spiral spring is always compressed during both movements. As the side force decreases, the spring force proportionally increases, forcing the steering knuckles back into the straight-ahead position.

The DCT units feature 14 degrees of steering angle. SAF self-steering axles are capable of achieving a steering angle of up to 20 degrees based on the track, spring centres and type of wheels installed. An electro-pneumatic locking mechanism, which is easily controlled by the trailer EBS unit, makes reversing possible by setting the self-steering axle to rigid. A cathodic dip coating process on particularly exposed parts such as axles and hubs ensures that all SAF axles offer long-term corrosion protection.

“Although we mainly left it to SAF-Holland to best explain the features of their product to the Campbell Transport team, one of the main reasons we recommended SAF-Holland for this order was a quick lead time,” Tony says. “With the current state of things with the pandemic that makes it quicker for us with our job. We have been sourcing products from SAF Holland for four years and in that time, we’ve had no major issues. They have good products that are fit for the purpose. Their team has been on top of any issue that we may have encountered. Currently we source around three-four products from them. We started out sourcing heavy-duty off-road axles and suspension, which are both great products. In the recent times though we mainly go to them for lightweight spring suspension and disc brake axles for side tippers. They also have a very good warranty offering with their products.”

Duraquip has delivered over half of the order to DCT, where the units will join over 500 trailers and 90 prime movers already at work for the WA-based business. DCT operates from various depots across the state in applications as diverse as mining, heavy haulage, grain, refrigerated, livestock carrying and compost. Designed especially for use in the iron ore mining and transport division, these ultra-quad heavy-duty combinations are all geared up for a tough road ahead.