How do you ensure a 7.5 tonne mine clearance vehicle can drive safely over a minefield without setting off explosions? Michelin's answer is to create a tyre so soft and with such a massive footprint that it could roll over a plastic coffee creamer pot without squashing it.
Unveiled ahead of the Eurosatory 2014 defence expo, the snappily codenamed LX PSI 710/75 R 34 runs at just 0.3 bar of pressure without generating the overheating that can cause under-inflated tyres to burst or suffer a short lifespan. The tyre was ten years in development as progress was temporarily put on hold while anti Improvised Explosive Device (IED) and bullet-resistant tyres were in greater demand during the asymmetric combat taking place in Iraq and Afghanistan.
The company brought the materials expertise of its 6,600 researchers and €640m operating budget to bear on the new tyre, which is painstakingly hand-crafted by Michelin specialists. The casing is based on Michelin's agricultural tyres, to which a wide, 10cm thick foam band is manually affixed then covered with a fine rubber film called 'skim'. Combined, these enable the tyre to safely operate at record-low pressures while creating the longest possible footprint.
Now Michelin's anti-landmine tyre has been selected for use with MBDA's SOUVIM 2 system-of-systems for the French Army, which stands for Système d'OUVerture d'Itinéraire Miné, or Mined Route Opening System. Having passed all the military's 'stealth' tests for anti-landmine tyres, the LX PSI 710/75 R 34 has been awarded original equipment certification.
Fitted with the tyres, which each weigh 200kg, the 7.5-tonne lead vehicle in SOUVIM 2 exerts a ground pressure of just 360g/sq cm, even less than a 2.5kg rabbit, which applies a comparatively hefty 450g/sq cm. While the SOUVIM 2 solution includes equipment to safely detonate mines, the tyre could also be used on security, rescue and evacuation and supply vehicles to enable them to traverse minefields safely.
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The SOUVIM programme was developed in response to a change in the way mines were used in combat. Until recent decades, minefields were restricted to the front line where they were set to prevent the enemy advancing its front line, and breaching countermeasures could be used. But the nature of France's military interventions from the 1990s onwards has driven a shift towards the route-clearing methodology.
The French Armed Forces bought five Meerkat/Husky road trains from Armscor, the arms procurement agency of the South African Department of Defence in 1995 to conduct studies on the best way to address these new threats. Based on the findings of these studies, France's military procurement bureau Direction Générale de l'Armement offered MBDA a contract in 1999 to carry out the design of the system that came to be known as SOUVIM 2.
Softer means safer
Not just a single self-contained vehicle, SOUVIM 2 is a countermining system that consists of a combination of mine detection and decoy sub-systems. Michelin's tyre is fitted to the lead vehicle, the Véhicule Détecteur de Mines (VDM), whose function it is to detect or decoy the mines.
A VDM fitted with the Michelin tyres can carve a safe path through a minefield at a speed of 10km/h, covering up to 150km a day. The tyres are so squishy that not only do they not set off flat landmines, but they will deform over the tops of conical landmines without activating them.
The VDM is manned and, while having tyres that are far less likely to set off mines offers some degree of defence, the crew and vehicle itself are protected from any under-body blasts by a V-shaped hull. To keep the weight down and maintain the VDM's stealthy tread, the defensive design is based around deflecting any blast away from the driver's cabin rather than using heavy armour.
The other elements of SOUVIM are the Véhicule Tracteur de Remorques (VTR), which tows the various trailers, and the trailers themselves, Remorques Déclencheuses de Mines, which trigger the mines.
The VDM uses a series of pushed decoys in front of it to bait any mines and IEDs in its path, then tows an initial mine triggering trailer to secure the path taken by the second vehicle, while marking out the route is has cleared. In regions such as Afghanistan, where IEDs present a bigger threat than mines, MBDA offers a VDM + system which consist of an autonomous non-towed vehicle equipped in front with a pushed heat, weight/pressure and electro-magnetic decoy system as well as a metal detector.
The VTR and its trailers then follow within the path marked out by the VDN. Each has fused wheels with progressively larger wheelbases to set off any explosives with its weight, ensuring the entire breadth of the path has been made safe.
French Army leads the orders
The French Army ordered four SOUVIM 2 systems in 2007, and the system is now in series production with three counter-IED version systems having been delivered to the French Army, two of which have been deployed in Afghanistan.
SOUVIM 2 is now being offered internationally, and MBDA has partnered with Force Protection Incorporated in the USA to create an alternative SOUVIM system-of-systems incorporating Buffalo MRAP vehicles. Known as Netted Route Clearance Capability, it uses a secure jam-resistant data link between all the vehicles, enabling crew to remain safely inside the Buffalo while controlling SOUVIM 2's sensors, decoys and effectors remotely.
In terms of military solutions, bigger is not always better, but for Michelin's anti-mine tyre and France's SOUVIM solution, softer certainly means safer.