SubscribeA new weapon has been added to the arsenal threatening troop installations and other facilities in the War on Terror.
Cars and trucks are being used extensively as the missiles to attack ground targets. Their effects are obvious to anyone watching the media.
The new factor in current operations is the willingness of the opponents to sacrifice their lives in delivering their deadly cargo. As a consequence, the vigilance of defenders goes far beyond such traditional measures as identifying suspicious vehicles parked in a potentially vulnerable area.
Forces are aware that in addition to defending against remotely launched missiles, they must also defend against the entry or approach of unauthorized vehicles to defended facilities. This is achieved in two ways; first, by entry control at well-defended locations, and second, by physically preventing entry in other areas.
Concertainer from Hesco Bastion Ltd is used extensively in both situations. At controlled access points, HESCO Concertainer forms protective bunkers and emplacements from which defenders can observe vehicle entry and if necessary take offensive action. These structures are available either as pre-configured sets such as the Hesco Bastion Limited's Sangar/Guardpost or as purpose-built structures. Many military facilities in current areas of operation use extensive perimeter walls using stacked Concertainer units.
A most common configuration is a pyramid of three units, providing a wall nine-feet high and a base thickness of seven feet. This configuration provides excellent protection against direct-fire attack and mitigation against effects of larger caliber weapons and bombs. The protection provided in these applications is widely understood as a result of very extensive evaluation in the United States, Great Britain, and elsewhere, as well as field experience generated around the world since the first Gulf War.
The effectiveness of Concertainer structures against vehicle impact has, until recently, been less well documented. While it was clear that the mass of fill would seriously impede a vehicle, no trials had taken place to prove the effectiveness of various structures and quantify the results.
Another aspect that was important to defenders was the possible generation of fragments from the wall itself after vehicle impact. Again, blast trials had proved that there was very little danger of a Concertainer wall generating fragments even under very large blast attack, but there was no test evidence to prove that would be the case in a vehicle attempting to breach the wall.
In the spring of 2004 two tests took place investigating different aspects of the use of Concertainer emplacements as vehicle crash barriers. The first test was conducted by the Transport Research Laboratory, in the United Kingdom.
The purpose of this test was to evaluate relatively small stand-alone Concertainer "blocks" which might be used to force approaching vehicles to slow down through a chicane prior to being searched at a controlled-access entry point. The test evaluated several systems of traditional traffic-control structures as well as those made using the Concertainer system. Traditional barriers are effective for normal drivers; for a determined terrorist willing to sacrifice himself and his vehicle, the requirement becomes to physically stop the vehicle.
The test threat vehicle was a 7 1/2 tonne commercial flat-bed. This vehicle was selected, as it is the largest vehicle that can be operated in the United Kingdom without a heavy goods operators' license. The impact velocity was 42 miles per hour.
Two tests were carried out. The first used two Concertainer Mil 1 cells, each of which is four-foot six inches high, with a footprint three-foot six inches, square. The two cells were perpendicular to the approach of the vehicle, so the wall was three-foot six inches thick and seven feet wide.
The units were filled with a sand gravel mix, compacted by the constructing Sappers by foot as they distributed the fill in the cells. The wall was founded on a concrete slab, which was considered to be the worst case, as there would be minimal friction between the fill and the slab.
The threat vehicle hit the centre of the wall with a mighty thump! Once the dust settled it was clear that the vehicle was destroyed and the driver would have achieved his desire for suicide, with or without a bomb. The vehicle was stopped in approximately twenty feet, using the United States Department of State criteria, described shortly.
The second test was exactly the same as the first, except that the block was four cells, two wide by two deep, providing a structure seven feet thick and seven feet wide. The results of this test were the same except that the vehicle was stopped in about eight feet.
Observers to these two tests determined that Concertainer blocks would be most effective in this role and others where channeling of traffic, with these rapidly-emplaced and imposing units was required.
The second series of tests were carried out by the United States Air Force, Force Protection Battle Lab at a disused airfield near San Antonio, Texas. The purpose of this test was to evaluate a Concertainer barrier in a configuration typical of perimeter walls for military and other vulnerable facilities.
The tests were based on criteria developed by the U.S. Department of State for vehicle crash barriers. As there is often very little separation between the perimeter and vulnerable facilities, especially in embassies in urban areas, the criteria are very demanding. In general, the structure must stop a 15,000 pound vehicle, traveling at fifty miles per hour within one meter of the inside face of the wall, a most demanding requirement!
For the test a pyramid configuration of one Mil 1 unit upon two Mil 1 units was used. The length of the structure was thirty-two feet and the impact was in the centre of the wall. The wall was nine feet high, with a base thickness of seven feet. They were filled with coarse sand and foot-compacted. Again, the vehicle impacted with a mighty thump! The vehicle was essentially stopped dead, with penetration, as measured by the Sate Department criterion, only three feet into the outside face of the wall with virtually no penetration past the inner face.
While a segment of wall only thirty-two feet long was used, there was virtually no displacement at the ends of the wall, indicating that the wall, as a whole, would have maintained its integrity. Another aspect which was important to the evaluators was that no secondary fragments were generated from the wall and any bits detached from the vehicle were captured by the remaining soil mass. Observers agreed that the test was most successful!
While it has been intuitively evident that a HESCO defence emplacement comprising a Concertainer structure constructed from Mil units would make an effective vehicle barrier, these two tests have proved the premise. The product's inherent characteristics of flexibility, rapid construction, and effectiveness were as applicable to vehicle crash as they were to ballistic and blast attack. They will reinforce the confidence of force protection designers and personnel protected by HESCO products in general, and Concertainer structures in general against those threats that constantly face them.
*HESCO, CONCERTAINER and MIL are all trade marks of Hesco Bastion Ltd
Further information can be found at www.hescobastion.com
