Australian military gears up - armoured vehicles upgraded

Materials World magazine
,
24 Sep 2013

Cameron Chai looks at the materials and technology behind the new protected mobility vehicle set to join Australia’s defence force fleet.

For the majority of the automotive industry, the design of the next generation of vehicles is driven by carbon emissions reduction targets as well as consumer demand for the likes of driverless technology. For the military, however, of more concern is protecting soldiers against enemy threat on the front line.

Since 2011, the Australian defence force has been looking to upgrade its current fleet of protected mobility vehicles (PMVs) and replace around a third of its light capability Land Rover models, which, having been in service since the early 1980s, are nearing the end of their 30-year life. After considering a range of replacement models (including those classified under the US Joint Light Tactical Vehicle (JLTV) programme – such as the BAE Systems Valanx, General Tactical Vehicles JLTV Eagle, Lockheed Martin JLTV, Navistar Saratoga, Oshkosh L-ATV and the AM General BRV-O), in December 2011, Thales Australia’s Hawkei vehicle was selected for development and testing under Stage 2 of the Manufactured and Supported in Australia (MSA) option, as part of LAND 121 Phase 4. The global defence services company has since been working on developing this new PMV fleet under the Australian Department of Defence programme.

Thales is no stranger to the Australian defence force, having designed and manufactured the Bushmaster PMV currently in military use. The vehicle has proven its worth in both its native country and in UK and Dutch militaries, protecting troops in hostile and unforgiving environments such as Afghanistan. While the Bushmaster has the ability to transport up to 10 troops, the Hawkei will serve as its smaller brother, with a maximum capacity of six. Namesake of the Acanthopis hawkei – the stealthy native Australian species of death adder – Hawkei is currently undergoing the final stages of testing. The project, which is worth AUS$1.5bln, will result in the supply of 1,300 protected and unprotected light vehicles to replace part of the Land Rover fleet.

Thales has invested AUS$30m in the design of the seven-tonne 4x4 vehicle to ensure it meets the required military-standard levels of blast and ballistic protection against the likes of improvised explosive devices (IEDs), mines and small arms fire, while delivering necessary mobility, performance and payload capacity.

Designing the hull
Hawkei meets this strict brief primarily through its mobility and crew protection cell. Paul Harris, Director of Strategy, Sales and Marketing for Thales Australia, says that the key to this lies in the shallow, V-shaped hull design. ‘The hull provides both structural integrity to the whole vehicle and 360° protection against small arms, shell fragmentation, and mine and IED underbelly blasts,’ says Harris. ‘The hull deflects some of the energy, with the remainder being absorbed using a sophisticated hull floor design via an internal floating floor and suspended seats to isolate troops from blasts. The shallow V-profile also provides good accessibility and ground clearance.’

The kitted design of the monocoque hull uses SMART armour technology, an innovation of Israeli armour and combat vehicle design company Plasan Sasa. The lightweight system is widely recognised for its multi-hit performance, which it achieves via a three-layer construction (see diagram below). The A-structure layer features an inner spall liner made of autoclaved aramid fibre composite bonded to steel armour plate, and provides the structure of the hull. The outer B-layer comprising a matrix of ceramic cylinders applied in panels completes the system. The ceramic panels can be applied by troops in around 30 minutes without the need for any specialist tools. Furthermore, its level of protection can be scaled via add-on applique armour kits (layer B) according to the in-field threat level.

However, designing the structural monocoque system proved more challenging than conventional body-on-frame military vehicles. Plasan's Michael Piha explains, 'Ceramic makes excellent armour because of its hard nature, but it is also brittle and therefore unsuitable for structural applications, such as a vehicle body. In a steelbased design such as Hawkei, the ceramic would simply crack under the stresses of the dynamic loads.'

The solution came in using the SMART armour in combination with a so-called kitted hull approach. On the former, Piha explains, 'Each of the thousands of ceramic cylinders in the armour can take high loads without breaking. The matrix of cylinders allows each panel to defeat multiple close hits of ballistic threats and shrapnel without significant damage to the surrounding area.' Furthermore, he says, because the ceramic modules are able to flex together with the underlying vehicle body, the armour will last the lifetime of the vehicle without any reduction in its protective capabilities.

The kitted hull approach involves bolting together the metal-composite armour panels that form the structure. This method has advantages in mass production, due to the absence of welding on the assembly line as well as the ability to combine dissimilar and non-weldable materials. In the case of Hawkei, it also allowed optimisation of the critical balance of weight, threat and cost.

Because the vehicle not only has to cope with the everyday stresses of off-road driving but also with the massive forces of underbody and roadside explosions, Thales and Plasan subjected the hull to several controlled mine blast tests (including sequential underbelly, ballistic and side tests) to ensure it met Australian ballistic and blast protection requirements, all of which it exceeded.

Testing performance
To date, Thales has supplied six prototype Hawkei vehicles and a prototype trailer to Australia’s Department of Defence. They are currently undergoing extensive testing at the Monegeetta Proving Ground in Victoria as well as at other Commonwealth facilities. Crucial factors under assessment include Hawkei’s communications system, mobility, payload, and air and sea transportability. Australian troops are also carrying out user assessments on the vehicle.

The survivability testing programme, supported by Australia’s Defence Science and Technology Organisation, is assessing the vehicle’s protective capabilities via tests performed according to NATO standard AEP-55 STANAG 4569, which covers strikes from kinetic energy, artillery and IED blasts.

Should testing prove successful, final approval of the project is expected around 2015, when the new Hawkei models will be deployed on the battlefield. Thales has further plans to export Hawkei, enabling increased levels of troop protection to defeat enemy threats on a global scale.

Protection racket
In addition to the hull, several features are integral to the success of the Hawkei:

  • Drivetrain layout – the engine and transmission are located side-by-side, so only the driveshaft passes under the crew compartment. The transmission and transfer cases are forward of the firewall, meaning the hull is free of potentially highly damaging heavy components being blasted into the crew cabin from underneath and so improving blast protection.
  • Windows – made from bulletproof glass.
  • Engine – lightweight, 3.2L twin-turbo diesel engine.
  • Tyres – central inflation system and optional runflat inserts.
  • Transportable configuration – allows the vehicle to be rapidly deployed using CH47 Chinook helicopters.
  • Vehicle health monitoring systems – alongside integrated logistics support (ILS) systems from Boeing Defence Australia, the health and status of the vehicle can be monitored, allowing predictive maintenance and, therefore, reducing the cost of repair.