There are many factors which improve the survivability for a vehicles occupants and designers have to balance them.
If one starts with a deep V shape hull to deflect blast from mines, geometry means that in order to have a useable volume it has to be high. Height raises the centre of gravity which makes it more prone to toppling over caused by side blast or terrain. Adding additional side armour to protect from projectiles, shell fragments and RPG attack will make the high centre of gravity problem worse.
To counter this, the designer might widen the wheelbase but this might mean it becomes too wide to negotiate narrow streets where one might want to go. Turning circles are likely to be reduced by this as well. Wide turning circles are a particular problem in the confines of built-up areas, unless the vehicle can reverse at speed it might be stuck in a vulnerable position or even under attack whilst trying to execute a 23 point turn. In this respect tracked vehicles have a great advantage because they can turn on their axis. UK and US experience in Iraq highlighted the utility of tracked vehicles in built-up areas, the manoeuvrability of the Bulldog (a modified FV432) was particularly useful.
If stability can be solved by width a vehicles height might not necessarily be a bad thing, providing the occupants with and increased field of view, the higher you are the greater distance you can see, especially when there are obstacles or vegetation nearby. On the down side, high vehicles are harder to conceal and can be dangerous in areas with low power cables.
Having the occupants strapped inside a survivable cell obviously protects them should they contact an IED but they lose all situational awareness which might mean they become more vulnerable to for example, an ambush or direct fire attack. In certain operations the ability to present a low threat visual image and having easy access to a local population might engender greater cooperation leading to improved intelligence, yet another means of defence against attack.
Weight is always a problem for vehicle designers and in areas with poor road and bridge infrastrucure trundling around in 20 tonne plus armoured vehicles leaving a trail of devastation behind it is not likely to engender good relations with the local population.
As the designer seeks to counter one danger it impacts on the ability to counter another, the age old trade off measure-countermeasure is played out.
No vehicle is indestructable, the best protected armoured vehicle in the world, the Challenger 2, has been penetrated by an EFP IED but against a blast mine or large IED there is no better place to be than in a blast protected MRAP/PPV.
Some say the Finland was the originator of the V shaped blast resistant vehicle but it is certain that the concept was perfected by Rhodesia and South Africa during the 70’s in their various brush wars and insurgencies. There are some parallels with Afghanistan today, the mine and IED was and is the weapon of choice for a force that cannot match the firepower, training or discipline of the conventional forces ranged against them. The Rhodesian and South African armed forces and industrial base more or less neutralised the mine as a strategic weapon and whilst the terrain and other conditions are different in Afghanistan, is there something that can be learned from their experience, perhaps yes.
The terminology is also of note; the South African and Rhodesian forces termed them Mine Resistant Vehicles (MRV), the US forces Mine Resistant Ambush Protected (MRAP) and the UK Protected Patrol Vehicles (PPV). The UK also used the term Mine Protected Vehicle to describe the types used by the Royal Engineers in the Balkans for route proving, IED recce and CASEVAC.
There are different types of weapon that present different challenges for vehicle designers but they are often grouped under one banner. The purpose built mine, the improvised explosive device (IED) that might use ‘home brew’ explosives, the vehicle borne IED and the Explosively Formed Projectile (EFP) or off route mine all act differently against a vehicle. A V shaped hull is unlikely to offer any protection against an EFP, which have even penetrated the armour of a Challenger tank. A VBIED’s resultant sideways blast may topple a high flat sided vehicle. Modern anti tanks mines rely less on blast and have EFP warheads. Surplus munitions such as artillery shells are sometimes combined with other explosives and the tactic of linking or dasiy chaining explosives to magnify the effect or shape a reaction in the accompanying units is a tactic that was practised in Africa and seems to be on the increase in Afghanistan.
As we said above, solve on problem and it makes another worse. There is simply no universal solution which makes vehicle design simply one part of a comprehensive counter Mine/IED strategy.
The history of these vehicles is very complex with a number of manufacturers and designers being involved over many years, a book could be written on the subject alone. We have split the evolution of the blast resistant vehicle into a number of distinct phases;
Initial designs took existing truck or Land Rover chassis and applied the V shape hull concept. The success of these first attempts was great but deficiencies were recognised and over the years the design concept was perfected, branching into a number specialist vehicles and designs that were no longer conversions but built from scratch.
Taking an existing chassis and transplanting a V shaped hull created an effective but very top heavy and ungainly vehicle, they were often toppled by blast but despite this its occupants more often than not survived, unlike in conventional vehicles. The injuries that did occur whilst riding in these vehicles were mainly as a result of ignoring standing orders and procedures about strapping in or securing loose objects. When subject to a large mine strike even a loose cigarette lighter can be a fatal projectile. Many of these early designs were also transplanted onto railway vehicles which were proving vulnerable to mine attack.
The Buffel was probably the most widespread of the type and consisted of a V shaped hull fitted to a Unimog chassis and with extra wide wheel rims to try and counteract the stability issue. An armoured cab was fitted, dispensing with the passenger seat allowed the creation of a protected citadel for the driver that also ensured any transmission or engine components did not intrude into the drivers area during a mine contact. A number of variants were produced, some armed, some unarmed and a wide number of mechanical enhancements. Retaining the basic mobility of the Unimog it still suffered in very wet conditions, after heavy rainfall for example. The Buffel was a significant export success and has been extensively used in Sri Lanka where the locally produced version is called the Unibuffel, a snip at less than £30,000. A particulalrly useful feature of the Buffel is a very large water tank, invaluable in areas where water was a scarce commodity.
For further information and a series of excellent pictures see here
The Concept Refined
In order to address a number of issues including the high centre of gravity, the concept of a monocoque hull was developed, without a separate chassis, the hull formed the chassis rather than sitting on it.
The Mamba still used Unimog running gear but without a chassis, relying in the monocoque hull. These types are characterised by employing a sacrificial drive-train and wheels, the engine and gearbox are inside the shell.
The Casspir was designed in response to a police requirement and is one of the most widely known vehicles of the type (even appearing in a Gorillaz music video for ‘Dirty Harry’)
In a widely reported incident a Casspir detonated 4 TM57 landmines arranged in two stacked pairs, one pair under the a wheel and the second pair linked a meter away. The vehicle was launched into the air but the most severe injury sustained by the occupants was a broken ankle. The TM57 has just over 6kg of high grade military explosive.
Up to Date
BAe, Navistar, Force Protection, Integrated Convoy Protection and Oshkosh (amongst many more) are currently manufacturing a wide range of blast protected vehicles, all of which can trace their conceptual roots back to those Land Rover and Unimog based lash ups produced by the South Africans and Rhodesians.
An example is the BAe RG31 Family, Force Protection Cougar/Mastiff or Thales (Australia) ADI Bushmaster;
The UK is no stranger to using these vehicles, having developed route proving and casevac techniques in the Balkans using Alvis 4’s. These were replaced by the Tempest vehicle, not widely known, the contract was let to Supacat (of Jackal fame) and used an early version of the Cougar, the same vehicle that subsequently became the Ridgeback, the vehicle at the centre of the recent ‘waiting at Dubai’ controversy. The base vehicle was obtained from Technical Solutions Group, a subsidiary of Force Protection, the manufacturers of the Mastiff and Ridgeback.
8 Tempest vehicles were purchased at a cost of £2.7 million (http://www.theyworkforyou.com/wrans/?id=2006-10-31c.80541.h) or roughly a third of a million each. We always caveat these figures with the statement that we don’t know the nature of the contract and whether it included documentation, initial logistics package, training or any of the numerous other factors that can make dividing the total cost a programme by the numbers of units, meaningless.
Its an unfair comparison but worth making anyway, the Sri Lankan Unibuffel costs less than £30k.
The UK has purchased the Mastiff (a derivative of the Force Protection Cougar 6×6) with UK specific communications fit, electronics, remote weapon station and other modifications including extra armour on the sides in place of the glass view ports. The Ridgeback is the UK version of the Cougar 4×4, again from Force Protection. The Mastiff 2 is now in service and includes a wide range of improvements. The Wolfhound Heavy Support Vehicle is a protected logistic vehicle used for towing the 105mm Light Gun and transporting various loads, based on the Mastiff it is in service in Afghanistan (or will be very soon)
One of the early wheeled detection vehicles was called the Pookie (Night Ape) and consisted of a highly modified VW Beetle. It had a deep V shaped driver’s compartment, very low pressure surplus racing slick tyres and an electronic mine detection system. Although relatively slow it was very effective and during the latter years of its service the enemy was known to have placed a bounty on it!
In 1979 a number of Pookie’s detected an average of just under 6 mines per day and built at a cost of less than a single damaged vehicle repair they were a great success. None were lost to land mines although a number were damaged in ambushes that specifically targeting them. Only 1 driver was killed by a direct RPG hit. Responding to the threat of ambush they were fitted with the spider, a fearsome 24 barrel 12 gauge shotgun providing a 270 degree arc of fire.
The concept embodied by the Pookie was developed further into the Meerkat and Husky vehicles as part of the Chubby mine detection and removal system. The Chubby system from RSD utilises a range of V shaped and open frame vehicles to both detect and disrupt mines and IED’s. The detection vehicles are very low ground pressure but the detonation vehicles have staggered wheels and high ground pressure. The UK purchased 3 complete sets for use in the Balkans although their status today is unknown. An unmanned conversion kit is also available. The US has a version called the Ground Standoff Mine Detection System from General Dynamics.
The Force Protection Buffalo is a heavier design fitted with a variety of sensors, space for mine clearance robotic vehicles and an articulated clearance arm. A number have been purchased by the UK as part of the Talisman programme.
Hopefully this post has illustrated the complexity of designing blast resistant vehicles, their history and the fact that the UK armed forces are no stranger to them.
One of our commenters (see below) has highlighted a few shoddy errors in this post concerning the early UK experiences with this type of vehicle, the Alvis 4 and Tempest. Apologies for these and a big thank you to STL for putting us straight on these points. The article above has now been corrected.
For much more detail on the South African and Rhodesian experience of mine warfare we would thoroughly recommend having a read of ‘Taming the Landmine’ by Peter Stiff.