By Jake McQueen, Product Manager for HESCO Bastion Concertainer®., HESCO Bastion Concertainer®
SubscribeHESCO Bastion Concertainer® units were originally used to provide protection against ballistic attack from small arms fire. The changing requirement of force protection prompted the introduction of bunkers that would protect personnel against stray mortar and artillery rounds.
In response to the threat of attack by VBIED, defense walls built from Concertainer units were developed, and have become the standard equipment for protecting personnel, equipment and facilities from a wide range of munitions and IED’s.
Today’s terrorist and insurgent are employing targeted mortars and artillery rockets, resulting in casualties being sustained inside hitherto safe camps. This has resulted in many countries with troops deployed in hostile environments demanding the provision of overhead protection, for either living accommodation or for cabins housing camp critical or mission critical assets.
HESCO Bastion has again been imaginative and pro-active in developing a means of defeating these new threats, with the design of the Extended Overhead Protection System (EOPS).
HESCO Bastion originally approached QinetiQ to design a means of providing side and overhead protection for a Weatherhaven MECC Shelter. The MECC is approximately 22' wide, much wider than the normal spans that HESCO Bastion caters for with their standard bunker kit.
QinetiQ are one of the world leaders in the design of fortifications. They are prime contractors to the UK Ministry of Defense, and are also contracted to HESCO Bastion to provide high-level force protection and blast mitigation advice. QinetiQ have extensive experience gained from a range of peace support and internal security operations.
EOPS was designed by QinetiQ using structural engineering analysis and evidence from past testing on munitions systems against HESCO Concertainer units.
The system was designed to withstand an attack from 81mm mortar bombs, typical of the size currently used by insurgents in Iraq. However, as anticipated by both QinetiQ and HESCO Bastion, EOPS will provide protection against much larger charge sizes.
MIL 3 and MIL 4 Concertainer units have been used for protection purposes on the system. A specially designed and manufactured locating cup is fitted to the four corners of an ISO container frame or similarly configured product. These cups provide the central support to the steel roof beams. The roof beams in turn locate into the Concertainer units. In addition, two short roof beams are used to bridge the access points.
The roof structure consists of a two 11m long roof beams. These beams have minimum yield strength of 170 N/mm2 and a minimum tensile strength of 410N/mm2. Two 3m-roof beams, with the same grade of steel are used to bridge the access point. 11m long steel sheet piles (made of the same grade of steel as the roof beams) are used to form the base of the overhead cover by placing them across the structure.
A parapet is then formed using MIL 3 units and finally the internal roof cavity is filled with soil until it is level with the top of the MIL 3 units.
EOPS covers a footprint of approx 11m x 11m, with an internal space of 8m x 8m. The walls are built from 1.5m x 1m x 10m long MIL 4 units on the base, with 2 layers of 1 x 1 x 10m MIL 3 units on top.
Advantica has successfully tested EOPS in the UK. Their Spadeadam Test Site is a major testing facility in the United Kingdom. The company has a proven pedigree in the testing and study of oil and gas installations, and the effects of blast on a variety of civil structures and structural components. Advantica has tested products for both commercial companies and the UK MOD and security services at this facility.
The testing was carried out over three days and involved the use of C4 Explosives contained within a steel case 3-5mm thick. All charges were placed in contact with the roof to simulate an attack by cased munitions fitted with a super-quick fuse.
Charge sizes used were: 2, 5, 10, 15, 10, 15, 20, 25 and 30 Kg (66lbs). The testing was halted at 30kg when one shelter corner post suffered deformation of 50 - 75mm. Even at this stage there was no evidence of damage to the inside of the Weatherhaven shelter.
Pressure readings were taken during the firing of all shots; the heaviest shot only generating pressures inside the shelter of approx 7.5KPa (1.1Psi), with pressures of around 17.4KPa (2.5 Psi) inside the open part of the system structure. (The threshold for ear drum damage is around 5Psi)
As can be seen by the charge sizes, the structure had already been subjected to charge sizes totaling 112kg (246lbs) prior to the final and largest charge. These charges had produced craters in the roof fill typically of 600 - 800mm deep.
Various invited guests from a number of countries and organizations viewed part of the testing. Prior to the testing they were given a briefing on HESCO Concertainer and the purpose behind the testing. Delegates were then able to see two cased charges of C4 being fired, one of 10kg and the other of 15kg. Both of these shots had no effect on the integrity of the structure less a crater in the sand cover on the roof as would be expected.
EOPS offers an unrivalled level of overhead protection against all mortar bombs, 155mm artillery shells and 122mm rockets fitted with a super-quick fuse. In addition, EOPS provides greater flexibility and utilization of space, as bunkers can be placed side-by-side and end-to-end to form a large complex of shelters under one common protective roof cover.
If increased protection levels are required, internal walls built from Concertainer units can still be incorporated to provide internal compartmentalization.
The successful design and testing of EOPS means that for the first time ever, multiple cabin offices, living and dining quarters, command posts or field hospitals can now be placed in an easy to build, competent protective structure.
Further information on EOPS, or any other HESCO Bastion products is available at www.hescobastion.com
