Army turns spotlight on can't-see-me Benz

Despite its mottled olive green and khaki paintwork the army's G-Wagon stands out in the bush

The DTOs of the Land 121 Training Team have nothing but praise for the Mercedes-Benz G-Wagon.

And why wouldn't they, after a quarter of a century driving around in the proven but agricultural Land Rover Perentie?

To translate, DTO is an abbreviation of 'Driver Testing Officer' and the Land 121 Training Team is an army unit located at RAAF Base Amberley in Queensland. It's where military drivers undergo a week-long conversion course for the new Mercedes-Benz G-Wagon, which is the W461 (military spec) version of the civilian (W463) G-Class.

Earlier this week the army welcomed the media to the unit, to provide some background and demonstrate in the field the G-Wagons purchased from Benz under the umbrella of Project Overlander Phase 3A (AKA Land 121 Phase 3A). The importer is supplying 2146 vehicles to the ADF – with the air force taking some, but the lion's share going to the army. Overlander 3A also calls for the supply of 1179 Haulmark trailers, to be towed behind the G-Wagons.

Project Overlander is "the Australian Defence Force's vehicle replacement program," explained Major Tim Keeffe, Officer Commanding at the Land 121 Training Team. Overlander will eventually procure more than 7500 vehicles for service with the ADF and "G-Wagon is the first part of that."

Phase 3B concerns the replacement of the ADF's Unimog and Mack heavy commercial vehicles, and Phase 4 will see the introduction of the Protected Mobility Vehicle (Light) for use in war zones. Still in the prototype phase, the PMV is unlikely to enter service before 2020, meaning a selection of the ancient Land Rovers must remain in service until then. The Rovers will continue to work in hostile environments for years yet, but the G-Wagon won't. Apart from general service roles, the G-Wagons will be employed in humanitarian and disaster relief work, although one variant – the SRV – will be armed for surveillance and reconnaissance (hence the name), but principally throughout the top end of Australia. Units such as 51 RQR will be equipped with the SRV, for use throughout far North Queensland.

But the SRVs will represent a tiny percentage of the total G-Wagon fleet for the ADF, with other variants of the Benz workhorse including ambulance and mobile command post. Benz will supply the G-Wagon in 4x4 and 6x6 variants (cab chassis only), with Newcastle engineering firm G.H. Varley providing different modules to suit different purposes; everything from conventional goods carrying to a cage module for transporting dogs. With so much (literally) riding on the G-Wagon, the contract is a complex one by necessity.

"We're not just buying trucks," Major Keeffe said of Project Overlander, "We're buying an entire support system."

As an example of that, the ADF is not only purchasing the vehicles themselves, but also three years of spare parts initially. And that section of the Department of Defence that oversees Project Overlander – Defence Materiel Organisation, or DMO for short – wants to sign a contract for up to 15 years or beyond.

The operational conversion to the G-Wagon is not only facilitated by military staff (the DTOs), but also civilians from Vertical Horizons Australia (VHA). Similarly, maintenance instruction is provided by Scientific Management and Associates (SMA).

The back story

While the G-Wagon can trace its ancestry back to the 1970s, the Australian Army's vehicles are not only up to date, they're at the leading edge of development, thanks to input from the army itself. Benz management told motoring.com.au that the 6x6 was developed specifically for the ADF, but has now been picked up by the Swedish army too, the Swedes ordering 120 of them.

David McCarthy, Senior Manager for Corporate Communications at Mercedes-Benz Australia, says that the G-Wagon is being delivered to the army "on time and on budget."

"It's the best G-Wagon that's ever been provided to a military force," he also remarked.

That is why the rest of the world has been watching Overlander/Land 121 3A with considerable interest and Mercedes-Benz has even picked up the Aussie G-Wagon's Motec data logger for sale through its supply channels around the globe.

"Thanks to this project we've given [Motec] that exposure," said the Senior Manager and Head of Military Business at Mercedes-Benz, Mark Dixon, who also observed that the Varley modules for the vehicle were an "off the shelf solution" that had found a ready market in Singapore. Mr Dixon declared that the roll-out of the military-spec G-Wagon locally has been "a success story for Australian industry."

The G-Wagon is entering service first with the army's 7 Brigade (Brisbane) and 1 Brigade (Darwin). For the moment, 3 Brigade in Townsville will plug on with the Land Rover until supply of the Benz catches up.

The Vehicle

If you thought the civilian G-Class was expensive, be glad you're not paying what the army is outlaying for its G-Wagon fleet. No one has put a number to it, but the G-Wagon is reportedly about double the price of the G350 BlueTec, depending on the variant. Powered by a 135kW/400Nm common-rail diesel V6 that is Euro 5-compliant – and roughly twice as strong as the 3.9-litre Isuzu powerplant in the Land Rovers – the G-Wagon also features push-button dual-range transfer and a five-speed automatic transmission. Just like the civilian G 350 BlueTec, the army G-Wagon comes with three diff locks that can be selected on the fly by pressing the respective buttons in what passes for the centre fascia.

Payloads range from 1200kg (for the four-door wagon) to as much as 2390kg for the single-cab 6x6 'carryall' variant. According to specs provided, the G-Wagon's towbar loading is up to 150kg and the 6x6 single cab will haul 2700kg, not including the weight of the trailer.

To meet the needs of the Land 121/Overlander 3A contract, Mercedes-Benz has strengthened the G-Wagon's chassis rails to cope with air drops and the G-Wagon also features a wading facility that can be selected to keep electrics safe in salt water fording. Wading depth is 750mm in fresh water, or 600mm in salt water. You'll notice in the pics that the drivers turn off the headlights and wait a minute or so for the lights to cool before the vehicles enter the water.

Heavy duty coil springs for all axles (up to three for the 6x6 variants) are complemented by oil-filled dampers, unlike the gas units in the civilian G-Class models. Benz spokesman David McCarthy has told motoring.com.au that the civilian models are migrating to oil-filled dampers also, with effect from September production. The manufacturing facility at Graz in Austria originally specified AMG-developed gas dampers, but MB Australia has now insisted on the oil-filled units, which provide a better ride and are more durable in tougher conditions.

The front axle is rated up to 2200kg and the rear axles are good for 2800kg. Live rear axles are located by forged trailing arms and Panhard rods, but don't provide the same degree of wheel articulation as in the Land Rovers. But the G-Wagon's centre diff lock balances out traction from front to rear and diagonally so the Benz can proceed even with two wheels off the ground. The Land Rover can keep all four wheels on terra firmer longer, but once two wheels lift clear of the track it's in trouble.

All G-Wagons are supplied to the army with 16-inch alloy wheels. According to the army, there have been no problems with the alloys, even with tyre pressures dropped for offroad work. Original equipment tyres are provided by BF Goodrich, but a prototype SRV present on the day was being trialled with Goodyear Wranglers. These tyres come with additional (kevlar) protection for the sidewalls, but cost more without delivering significantly greater durability than the Goodrich tyres, the army has found. The standard tyres have lasted 18 months so far, with the only punctures incurred as a result of driver error.

Power steering, ABS and air conditioning are all fitted as standard in the Benz – a first for a vehicle in general service with the army. The air conditioning, in particular, has been welcomed by the military operators who drive the vehicles. Either selecting low range or enabling the centre diff lock will disable the ABS, according to Major Keeffe, leaving the driver no choice but "threshold braking" in an emergency. Other than seatbelts, the only passive safety feature fitted is the driver's airbag in the steering wheel hub.

The DTOs

Convoy commander for our run up to the 4WD park at Janowen Hills was Corporal Warrick Hickson. While very military in his bearing, Corporal Hickson is a bit of a revhead, just on the quiet. It was probably unavoidable growing up with a motor mechanic in the family. A serving member of the army for "six or seven years", Corporal Hickson currently owns an MA61 Supra and before that a Celica GT-Four. Toyotas seem to run in the family, with the old man whipping up a 300hp 4A-GE engine by bolting up a supercharger and a turbocharger to the 16-valve four-cylinder. The corporal is watching with interest the success of Toyota's 86 sports car – and he sounds like he might be seriously in the market for one.

Corporal Hickson initially had his doubts about the automatic transmission in the G-Wagon, but has found the vehicle to be very capable offroad and, when asked whether there was anywhere the Land Rover could go but the Benz couldn't, he simply replied: "I don't believe so." He says that it's the lockable centre diff of the Benz that offsets its stiffer ride and smaller degree of wheel articulation. The ADF bought TD5-engined Land Rover Defenders in the not-too-distant past, he advised, but offroad they proved to be "top-heavy" and, combined with their "narrow footprint" were prone to falling over.

Two aspects of the Benz that place it ahead of the Land Rover are the comfort afforded by air conditioning and the low levels of NVH, which Corporal Hickson explained allowed actual conversation to take place at 100km/h.

It was Corporal Hickson who introduced us to one of his colleagues, Corporal Brooke Shaw, a former soldier who transferred to the RAAF, but still instructs drivers for a living.

Corporal Shaw first came to our attention for a scene in an instructional video aimed at drivers new to the G-Wagon. None of the ADF personnel appearing in the video are ever likely to win a Gold Logie, but Corporal Shaw let her skills do the talking for her, applying opposite lock in a Benz as it oversteered its way through thick, soggy mud. Away from the Land 121 Training Team she drives a BMW 3 Series Touring to transport her two pampered poodles – a far cry from the way she spends her time during working hours. In fact, don't tell anyone at Benz, but the corporal is a fan of the BMW marque and is looking around for a good X5 to pick up.

Licensed to drive heavy commercial vehicles, she was behind the wheel of a 6x6 'Carryall' for the day the press attended Amberley and the Janowen Hills complex. Around the four-wheel drive park the 6x6 proved equally at home whether cresting steep grades in a quarry or fording a stream. It's a vehicle that rides better than the 4x4s, but Corporal Shaw prefers the agility of the shorter-wheelbase vehicles.

On the way back to Amberley she was confidently guiding the heavily loaded combination of 6x6 and trailer across narrow causeways and up steep hills. Clearly she loves her job and wouldn't swap it for anything – although the opportunity to refuel aircraft in her 'Air Movements' capacity was "cool".

If there's one downside to the job, it's "sitting there" – in the front passenger's seat watching her students behind the wheel. She would much rather be doing the driving...

Pictures courtesy of Cpl Mark Doran, Defence News:

Wagon demonstrates benefits of centre diff lock

6x6 fording the stream at Janowen Hills complex

Wagon fording the same stream

Single-cab 4x4 in the quarry

Wagon descending into quarry

Major Keeffe with 6x6 in the background

Corporal Shaw at the wheel of the 6x6

Corporal Shaw with SRV in background

Corporal Hickson with Corporal Tim Conquest at the wheel of the SRV