GUIDELINES SHATTER RESISTANT FILM I. INTRODUCTION

Transcription

1 GUIDELINES SHATTER RESISTANT FILM I. INTRODUCTION 1. In the event of an explosion, the resultant blast can shatter glass windows into razorsharp, knife-like shards and hurl these through the air at high speed. The results are likely to include significant material damage, together with possible severe injury or death to those in its path. Fortunately, there are materials readily available that can mitigate these effects and significantly reduce the risk of injury from shattered glass. 2. Shatter Resistant Film (SRF) for windows (which is manufactured by a variety of companies and marketed under several brand names) is now routinely used in diplomatic missions, government buildings and commercial organisations in various parts of the world. Shatter resistant film is effective for all types of blast including artillery and mortars, burst gas pipes, and other accidental or deliberate incidents of high-pressure releases. It should be noted that severe shaking from earth tremors, or residual blast, can also shatter unprotected glass. It should also be noted that there are no magic solutions to stop the effects of large blasts on structures. However, SRF is an effective mitigating agent and can reduce injuries and death. 3. The aim of this paper is to provide a field guide to the understanding, selection and installation of shatter resistant film. The paper will also explain the threat posed to UN staff from shattered glass caused by the effects of blast, together with a limited description of the characteristics of the effects of blast on structures. II. TERMINOLOGY 4. The following terms are used throughout the paper: a. Shatter Resistant Film. Shatter Resistant Film (SRF) is widely used in industry to describe the polyester laminate film that provides protection against blasts. The term Blast Protective Film has been used within the UN (including the MOSS tables), but should be replaced by the term SRF. SRF is a polyester material with its own bonding agent that is affixed to glass windows and walls. Its protection capability depends on the quality of the material, the adhesive glue, thickness of film, type of glass, application method and blast characteristics. b. Application. There are several ways to apply SRF to windows. The way in which it is applied will determine its ability to withstand pressure and whether the pane of glass will remain in the frame or be flung out of it. Weak window frames may rip out of their walls, complete with glass pane, and smash across desks or offices intact. The most simple form of SRF application is called Daylight Application ; when the film is cut to the size of the glass and adhered to it. Other forms of application may involve removal of the glass, wrapping the SRF over the edges and replacing it in the frames. Additionally,

2 batons may be fixed to strong frames to ensure the glass-covered SRF remains in the frame throughout the blast. However, this method incurs significantly greater cost. SRF must be applied only in accordance with the manufacturer s guidance. This may be done either by company technicians, or by UN staff who have been trained in its application. Note: Daylight application is likely to be appropriate for most situations. c. Shatter Resistance. This is the ability of the film to adhere and hold onto the shattered glass throughout the enormous distortion caused by the blast, without tearing and failing. Typically a very high percentage of glass will adhere to appropriate quality SRF (97%) under severe shattering (see attachment 1). d. Stand Off Distance. This is the distance from the target glass to the expected or actual blast origin. e. Armoured Glass. Armoured glass is specifically created glass of extreme robustness designed to defeat ballistic bullets and massive blast. It is heavy, thick, very expensive and requires expert and specialized frames and fitting. It is not included in this paper. III. EXPLOSIVE BLASTS AND THEIR EFFECTS 5. The weapon of choice for terrorists is explosives typically in very large quantities, and often in the form of vehicular bombs, suicide bombers or package bombs. Importantly, near misses from artillery, mortars, rockets and missiles also create an explosive blast and the effects may be similar to terrorist bombings. 6. The characteristics of an explosion will include: blast, flash and fragmentation. SRF is designed to protect against Blast only: 7. Blast This is the main cause of concern for window glass. Blast is caused by the release of enormous amounts of chemical energy from the explosive, resulting in an air-pressure wave traveling at high speed. The air-pressure (blast) wave can pick up particles and thrust them at great velocities. This force may initially be sufficient to rip steel and propel stones and pieces of metal like a shotgun. Large blast waves are capable of climbing up and over walls, up building walls, and may wrap around buildings, but they lose significant energy as they do so! 8. Flash This is the heat energy resulting from the chemical release of the explosive. It may cause severe burning to material and flesh. High quality SRF will not constitute a burning hazard. 9. Fragmentation This is a combination of large and small pieces of, bomb casing, stones, vehicle parts, ball-bearings, or loose material including wood fragments. High quality SRF will provide very limited protection against relatively slow moving fragmentation. 2

3 IV. PRINCIPLES FOR THE USE OF SRF 10. The decision to install SRF must evolve from recommendations following the conduct of an appropriate Threat Assessment. The Threat Assessment is a comprehensive study into the security aspects of the duty station and must be completed by a competent authority (i.e. UNSECOORD, Agency Security Officer, DPKO Chief Security Officers, etc). Once the threat has been established and understood, it will be necessary to assess the risk (likelihood and consequence) of the threat impacting on UN staff. 11. It is not compulsory to install SRF to UN facilities under baseline MOSS. However, SRF (termed blast protective film in MOSS) is mentioned in the annex to MOSS and may be added to a country MOSS if identified in the country Threat Assessment and approved by the SMT. These principles for use of SRF are provided for guidance only. They are based on technical information from SRF manufacturers, national and commercial security organisations, and practical experience from FSCOs in the field. There is no implied guarantee of safety and local information and advice should be considered before installing SRF for UN staff, whenever possible. The cost of SRF varies with the quality and application. A guide for the calculation of project costs is provided at Annex A a. Stand Off Distance. The Threat Assessment will determine likely areas where a blast may occur. The closer the blast, is to UN premises, the more damage will be caused. If a reasonable stand-off distance cannot be achieved (i.e. UN offices are on busy streets), then either; (1) personnel should be moved to a safer location, or (2) armoured glass should be installed (and walls reinforced). In addition, physical barriers should be used to keep vehicles away from buildings. This is the most effective protection against an explosion. The further vehicles can be kept away from windows and other potential targets, the better! An absolute minimum of 50 meters should be maintained. b. Materials. Unfortunately not all window film is designed or manufactured to resist the extreme effect of an explosion. Plastic window film designed to reduce glare or UV rays will not stop or significantly reduce the effects of an explosive blast. Unfortunately many UN buildings in conflict areas have already covered their office windows with this inexpensive film and believe it provides protection against blast it does not! Various manufacturers supply SRF. The commercial companies, 3M, Llumar and Du Pont manufacture high quality SRF products that are available widely throughout the world. Care should be taken to ensure that SRF provided by other manufacturers meet the minimum standards of this paper (based on the performance of 3M products). The use of wide packing-tape to cross windows will not stop or significantly reduce the effects of an explosive blast. In some circumstances it may provide extremely limited aid in securing glass during a minor earth tremor, or from minor pressure waves from distant artillery explosions..but not from the direct effects of an explosion! c. 3

4 d. Thickness. SRF comes in a variety of thickness. The unit of measure is commonly referred to as mils, or 1/1,000 of an inch. One mil equals approximately mm. The thicker the SRF, the stronger the film. Most SRF is of the range 2 6 mils ( mm). Generally, exterior windows facing a potential blast will require thicker SRF, whilst interior glass, and rear, external windows may only require a thinner film. It should be noted that different manufacturers use different measurements to describe the thickness of their product. e. Application. Regardless of the thickness of the SRF, the mode of application is a significant consideration. The cheapest application is Daylight Application. However, with this method of application the SRF together with the attached, shattered glass, may fly out of the window frame at high speed and crash onto the rear wall of an office, or across a table. It is likely that such an incident will cause injury to staff. Regardless of the application method, death and injury will be mitigated by correct SRF application. f. Target. The target is the glass doors or windows exposed to the blast. In countries of the developing world (where many UN staff operate), domestic grade glass is installed in UN offices. This is a low quality glass that shatters easily. g. Other Advantages. (1) SRF is a high strength material and resists smashing from blunt and sharp objects. However, it does not provide ballistic protection and only minimal fragmentation protection (dependent on thickness). (2) Although this does not add to blast protection, SFR typically provides high levels of UV light protection. It typically comes as a clear film, and Du Pont products will not yellow over time. 12. The installation of SRF is not a solution on its own. Once the need for SRF has been identified in a Threat Assessment, it must be a part of an integrated security system for the UN facilities and residences. The decision to use, or not to use SRF, is an accountable decision. Annex C contains a summary of the advantages and limitations of using SRF. V. CONCLUSION 13. SRF is a critical aspect of physical security protection. Although its application is a mitigating factor and is unlikely to eliminate casualties completely, when appropriately selected and applied, it will save personnel from injury and facilities/equipment from damage. Every attempt should be made to ensure that expert advice is obtained and the installation instructions of the manufacturer are followed when applying SRF. 4

5 Annex A INDICATIVE COST OF MATERIALS AND APPLICATION The general costs of purchasing and installing SRF provided in this Annex are based on general considerations regarding products from 3M, and using daylight application only. They should only be used as indicative costings as they will vary greatly. Further information on other manufacturers and enhanced application modes may be provided by UNSECOORD at a later date. Type of SRL Material Only Applied by Contractor 3M Product Description Shatter Resistance SCLARL150 (2 mils or 0.05 mm) ULTRA400 (4 mils or 0.10 mm) ULTRA600 (6 mils or 0.15 mm) $ $ $ $ $ $ High Strength Clear Safety and Security film Superior Strength Clear Safety and Security film Supreme Strength Clear Safety and Security film Least resistant to blast. Best for interior and other windows out of direct blast. Good resistance. Appropriate for general window usage. Best resistance to blast. Particularly for areas in High risk areas of blast. Cost of application can be reduced by having UN staff, or other local staff, trained by 3M as was done by a UN country team in South Asia who sent personnel to a neighbouring country for formal training in SRF application. The personnel then returned and installed SRF to all UN buildings in the country. Notes: 1. 3M data has been used in this paper for ease of reference. This is not a recommendation for their exclusive use. 2. All indicated costs are based on prices at New York rates, and include the use of 3M specialists installing the film. The variation is added to give a likely cost in other parts of the world. (no expectation of similar prices should be considered outside the USA). 3. Additional cost for application may be included for application if windows require cleaning, windows are non-standards size, and/or access is difficult. 5

6 Annex B ULTRA400 GUIDE TO DETERMINING THICKNESSES AND APPLICATION METHOD After determining the Threat and Risk, and consequently the need for SRF, security managers must consider the cost of the material. To ensure maximum cost-benefit a building under threat must be considered in relation to the exposure of the windows (and other glass) to a potential blast. Windows facing the threat need maximum protection, windows to the rear and internally may require minimum protection (some, or no protection), and other windows either on high-rise buildings or at the side and rear of a building may require a moderate amount of protection. By utilising different thickness SRF, the cost may be kept down. However, cost should not compromise safety/security and security officers and decision-makers may be accountable for their decisions as to the standard of SRF applied. This guide will use the 3M, clear, SRF products of 2, 4 and 6 mils thickness (SCLARL150, ULTRA400 and ULTRA600). (Windows at rear) SCLARL150 ULTRA400 (Windows at rear) SCLARL150 ULRA600 UN House 100+ meters ULTRA600 ULTRA600 ULTRA600 Identified car bomb location 30 + meters 6

7 B-2 EXAMPLE WHERE STAFF SHOULD NOT BE LOCATED UN House Less than 50 meters Tree Potential car bomb site limited vehicle access to building (30 m) These windows should be bricked-up, or high grade SRF installed. Even then, these rooms should be used for storage of non-vital equipment/stores. They should not to be used as offices or meeting rooms when this close to large blasts. 7

8 Annex C SUMMARY OF ADVANTAGES AND LIMITATIONS Advantages: SRF significantly mitigates the destructive effects of blast against offices and facilities. Greatly reduce the extent and number of injuries from flying glass. Reduces smash and grab theft. Reduces UV light into buildings. Widely available throughout many parts of the world. Limitations: SRF does not stop every tiny fragment of glass. May require additional strengthening of window and glass-door frames. Requires specialised installation. May trap all glass onto the SRF, but this could fly back into a room and injury/kill. Many similar, cheaper products that do not provide protection from shattered glass. The type of SRF to use, areas to be covered and application is poorly understood. It requires a significant cost to the system. It is not a magic solution and some areas are unable to be protected by SRF. SRF must be used in conjunction with all other security measures for the location. 8