INTERNATIONAL CONFERENCE ON MINE CLEARANCE TECHNOLOGY 2-4 July 1996 Copenhagen, DENMARK TECHNOLOGY FOR MINE CLEARANCE OPERATIONS PROTECTIVE EQUIPMENT FOR MINE CLEARANCE PERSONNEL Vernon P. Joynt GENERAL 1. Mechem are the people probably most qualified to speak about the aspects of vehicle mine protection in relation to the various threat situations. When it comes to personnel protection, they have some experience through their mine clearing research and involvement with EOD. One of the key issues on safety in mine clearing operations at present revolves around the final step where the deminer manually opens up the detected signal. The very large quantity of harmless signals opened up makes the men complacent and slows down the demining process too much. VEHICLES AND THREAT SCENARIOS 2. The principles used to protect personnel in vehicles and the vehicles themselves against the effects of landmine detonations are numerous. It is therefore more practical to put forward the requirement more common to the United Nations type humanitarian operations and go into detail about the equipment available to meet those requirements. Obviously the threat in the area of operations also play a big role. It is therefore necessary to describe these threats first. THREATS IN RELATION TO VEHICLE PROTECTION 3. Simple blast anti-tank mines. These occur in countries like Mozambique, Rwanda, Ethiopia and Uganda. Typically the charge weights are around 6 kg TNT (that is, TMA-3). 4. Boosted anti-tank blast mines. Especially in Angola, but also in Bosnia and Herzegovina, such mines occur in significant quantities. In Angola the added complication occurs that the mine fuses are not used and that the mine is triggered by means of an anti-personnel mine and detonating cord. The result is belly blasts under the vehicle (slides 1, 2, 2a and 2b). Slides 2a+b show a 30 kg plastic explosive main charge, lifted in the UNAVEM III road clearance contract. Note the two plastic pressure switches used to trigger the explosive. A mine like this is also extremely difficult to prod because the PE4 is soft and cannot be felt. Slide 2c shows the effect on an ambulance of a centre blast mine. 5. Projectile producing mines (SFF mines). These mines are of more modern manufacture and are particularly difficult to protect against, because they combine the penetration effect of a Misnay-Chardin self-forming fragment (SFF) with a normal AT blast mine effect. The most common example is the TMRP-6 mine manufactured in Yugoslavia that is estimated to occur in nearly 50 per cent of the threat in Bosnia and Herzegovina due to AT mines (slides 3 and 4). Protection against these mines require a composite armour kit fitted in a position as close as possible to the mine detonation (slides 9 and 10). 6. Anti-group anti-personnel mines. These mines produce shrapnel and therefore the vehicles must also have normal armouring of the hull. There are two types: surface Claymore types and buried jumping mines, usually triggered by means of a trip wire or pressure switch. VEHICLES 7. An early vehicle developed in 1972 by Mechem for the Rhodesian war was the Hyena (slide 25 shows the prototype), a combination of a lorry chassis, engine and drive train and a deep V-shaped armour hull. This quaint looking vehicle led to Mechem being approached by the South African military and the Police for mine protected vehicles both for combat and for border patrol work. 8. Thousands of Buffels (Afrikaans for buffalo), developed by Mechem, were manufactured for the Army. These had a mine and ballistic protected armoured cab and hull mounted on a Unimog chassis. The chief disadvantage of this vehicle was instability on sideways sloping ground, which could make cross country work hazardous. The military theatres in Northern Namibia and Southern Angola where the Buffels were used, however, was very flat sandy country on which these vehicles were excellent. The degree of protection was such that, in all the campaigns, less than 1 per cent of personnel involved in anti-tank mine detonations were killed. 9. A requirement from the Police, who were patrolling borders infested with armed insurgents in 1983, led to the development of the Casspir, possibly the first successful monocoque mine-protected vehicle. With a very high level of protection, the Casspir proved to be ideal in the bush, as its height offered an excellent view and the low centre of gravity made it very stable. The big advantage which the Casspir had over the numerous other mine protected vehicles in use at that time was that it could be repaired quickly and cheaply after a landmine detonation. This is exploited today in the mine clearing contracts that Mechem is doing. 10. A variety of other requirements for mine protected vehicles led to vehicles developed by other companies and organizations. They were based on Mechem design parameters and were explosion tested at the Mechem test range. About 1987, it was seen that the then border wars were near their end, and it was correctly postulated by Mechem that these would be followed by an upswing in urban unrest. Mechem commenced development of a new vehicle with a slightly lower level of mine protection than the Casspir, but with adequate ballistic protection for the circumstances expected in urban and rural situations, and much easier to drive in city streets and traffic. This new vehicle was named the Mamba (slide 27). Originally designed as a two-wheel drive vehicle, it exhibited mobility which was frequently better than other four-wheel drive vehicles in head-on competition. The present military version, however, is a four-wheel drive based on a Unimog. 11. It is the fortunate historical combination of the development of anti-mine techniques and of mine-protected vehicles which has led today's Mechem mine clearing expertise. 12. United Nations Operations need mainly two types of vehicle: a personnel carrier to replace the Land Rover type vehicles and mine protected load carriers to replace lorries (slide 28). At present being worked on producing a mine protected version of the M35 American truck. The purchase price must not be high. Typical prices acceptable by the military for light armoured vehicles is usually much too high for commercial operations. 13. In general the mine protected vehicles developed in South Africa are cheaper than most light armoured vehicles, but experience shows that there is scope for a smaller and cheaper vehicle. In the slide series some possibilities are shown. The series range from the big and heavy personnel carriers suitable for mine clearing operations (Casspir, Wolf and Okapi - slide 26), through the medium-sized vehicles like Mamba, Alvis 8 and RG31, to the light vehicles like the Ribbok, used by the South African farmers during the war years, and the Scarab under development at Alvis (slides 5, 6 and 7). 14. The use of water (+ 70 litres) in the tyres of normal trucks was found to reduce casualties in an AT mine explosion up to sixfold. This is due to the absorption of heat out of the blast, reducing overpressures and lengthening the time of the blast impulse. The protection offered by the so called TMRP-6 kit is shown with slides and the fitting to various vehicles, like the Mamba, Comanche, Cobra and the Scarab types, is indicated or possible (slides 8, 9, 10, 11 and 12). 15. The RSD mine-clearing system vehicles are also shown (slides 13, 14 and 15). These are available with TMRP-6 protection and the system is well suited for use in clearing corridors through mine areas where "wild" mines are predominant. PROTECTION FOR DEMINERS 16. Personal protection equipment like normal flak jackets, visors, helmets, gloves etc. will only be discussed where something new is available but not commonly used or gear under development may offer an advantage (slides 16 and 17). The total bombsuit is not really practical for most of the deminers, but is essential when clearing, jumping or other antigroup mines. Mine shoes, mine mattresses (slide 18) and high protection level visors and helmets are discussed. In the South African wars, two principles apart from the foam pad approach proved useful. Firstly a water pocket in the sole of a shoe and secondly a steel wedge shaped insert in the sole. IMPROVEMENTS PROPOSED TO SIGNAL INVESTIGATION 17. These techniques are now under test at the Mechem explosive range. The purpose is to put some distance between the position being investigated and the man. Time saving and safety are the major considerations. The following are involved: (a) The use of hypergols. These are chemicals which cause fire when coming in contact with explosives like TNT. (b) Mechanical techniques for uncovering a mine. A rotary brush technique is being investigated (slide 19) and shows much promise. It is proposed to introduce this into the Angola contracts. (c) Air jets for uncovering a detection signal (slides 20 and 21). (d) Water jets - slides show a water cannon and a water jet generator using detonating cord, both are proven EOD devices (slides 22, 23 and 24). A high pressure large system is also earmarked for use in the Benguela railway mine clearance contract. (e) Explosive signal interrogation using hollow charges or simple low-velocity detonation cratering charges. 18. Remote-controlled devices like the use of a bomb-arm as fitted to the mine clearing Casspirs (slide 14 - topic two).