High and Mighty

Mack has captured a lot of attention with its integrated 70-inch sleeper Super-Liner. Prime Mover puts it to the test in the outback.

Mack Trucks marked six decades of Australian manufacturing with the unveiling at this year’s Brisbane Truck Show of its latest Super-Liner featuring a new fully integrated walk-through 70-inch sleeper.

The new walk-through sleeper will be available in a variety of configurations as an option for the heavy haul oriented Super-Liner and the big bunk sleeper bolsters the Super-Liner’s already strong credentials as a heavy haulage and roadtrain prime mover with GCM’s available in excess of 200 tonnes, if required.

The 70-incher is more akin to a mobile apartment than a truck’s sleeper. In fact, it’s so roomy it was used as a recording studio for interviews by journos with Mack executives at the Brisbane Truck Show.

At the time we were offered the opportunity to drive the Super-Liner on a route through central Queensland in a roadtrain configuration and some months later we find ourselves at the wheel of what is a stunning looking rig.

The Super-Liner is liveried in show stopping glossy grey and black paint, combined with matt black fuel tanks and wheels reminiscent of vehicles featured in road warrior style movies which fits in well with the landscape along our route.

Our Mack journey commences in Mount Isa where we check over the Class 2 AB-triple combination which is grossing 90 tonnes with its 2,000-litre fuel tanks topped up.

The load behind the trailers’ curtains consists of IBC’s filled with water, which at certain times of the year out here would be worth more than gold.

Following its impressive debut in Brisbane, the Super-Liner has been fitted with several additional components necessary for safe operation in the wider outback including a bullbar, LED driving lights and external air filters with high level intake scoops.

It is impressed upon us that this particular Mack is a prototype and the only one in existence, so we commit to taking extra care of it. The first locally produced 70-inch sleeper equipped Super-Liners are expected to be delivered to customers in late 2024.

Peter Shields, testing the new AB triple.
Peter Shields.

Roads in central Queensland commonly consist of a sealed single lane, which requires easing off the throttle before dropping the kerbside wheels into the dirt when confronted with another approaching roadtrain.

This mostly happens seamlessly with the only communication required being a friendly wave of acknowledgement between the drivers. Lighter vehicles, many of them connected to large caravans, are required to pull completely onto the verge and stop for approaching roadtrains.

Most do, but the occasional fool will risk stone damage to their windscreens and will try us on. Steering 90 tonnes of truck off the sealed surface at 90 km/hr can be unnerving except for the sure footedness of the Mack’s steering and suspension which has undergone a comprehensive redesign including the steering box itself.

The result is excellent stability which contributes to driver confidence. Any steering input in a 44-metre long combination such as this can be amplified at the rear-most trailer and a ‘less is more’ approach to steering is a constant reminder to keep the left ear of the gold bull dog mounted on the bonnet aligned with the edge of the bitumen to maintain the correct position in the centre of the sealed lane surface.

The Mack’s stability is achieved using parabolic front springs and Mack’s eight airbag rear suspension. An occupational hazard for truck drivers in this part of the country are the herds of cattle which, even in this age of modern truck transport, can still be found being guided along stock routes by Aussie cowboys on horseback.

Confronted by a sizeable herd ourselves, timely advice is offered to us from one of the drovers to “Just keep rollin’, mate, they’ll get out of your way.” And they do, with no damage to livestock or Mack.

We arrive in Winton well before dusk and drop the trailers on the outskirts to enable us to run bobtail into the attractive town which boasts a wide main street and three thriving pubs all within 100 metres of each other.

This is the location where AB “Banjo” Patterson wrote “Waltzing Matilda,” and the countryside befits the images of the lyrics of our unofficial national anthem.

After an excellent meal at one of the pubs, I retire to the Super-Liner’s inviting full size bed. Despite the heat, leaving the Ice Pack air conditioning running while enjoying a steak at the pub means the cab is comfortably cool upon my return so the Ice Pack is switched off.

Cattle cross the road.
The journey is briefly disrupted at a cattle crossing.

The overnight temperature is easily maintained by keeping the air circulating through the use of the small fan fitted in the sleeper compartment. Hatch type windows on each side of the sleeper are equipped with insect screens and work well to provide cross-cab fresh air ventilation.

On the exterior the window hatches are hidden behind the aero fairings. The blackout curtains between the sleeping and driving sections have a magnetic seal which keeps the light out, even though we are parked in an area well illuminated by streetlights.

The king size single bunk is two metres long by one metre wide and the inner spring mattress helps induce a restful sleep until 4.00am when it seems every galah (of the feathered variety) in central Queensland is welcoming the approach of dawn from their vantage perches on the town’s powerlines.

The sleeper has a massive 2.1 metre ceiling height and is outfitted with a wardrobe with sizeable full hanging space as well as other storage lockers.

The use of the upright fridge provides the advantage of not needing to unpack a bunch of items in order to get to something located on the bottom. The control panel for lighting and the Ice Pack is readily accessible.

It also provides USB charging ports. The fridge, freezer and microwave oven look after the catering requirements while a DVD media player connected to a high-resolution colour television takes care of the entertainment.

The mighty 16-litre MP10 685hp engine delivers 3,810Nm (2,300 lbs/ft) of torque at as low as 1,000 rpm while achieving good fuel economy by hanging on in 12th gear and taking advantage of the 3.10:1 rear axle gearing.

Not only does the engine provide such impressive hauling capabilities, the three stage “PowerLeash” engine braking easily holds the 90 tonnes to account on descents with very little need to touch the service brakes.

Stage one is an exhaust brake, stage two is an engine compression brake, and stage three is the combination of both. Using the selector wand at its spring-loaded fourth position initiates downshifting the transmission to maximise the engine braking effect without risking over revving.

The Bendix Wingman fusion safety system is standard equipment across the Mack optimised spec range and features lane departure warning, blind spot alarm, adaptive cruise control, collision warning and autonomous emergency braking.

On the return leg to Mount Isa we appreciate how the Mack Super-Liner has been designed with the needs of the Australian driver in mind, providing high levels of performance, safety, comfort and handling, combined with a spacious and well-appointed sleeper cabin environment.

Mack roadtrain in outback Queensland.
Mack Super-Liner AB-triple.
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